Nisha Bhatia, Vandana K. Dhingra, Pulkit Mittal, Sunil Saini
Abstract Objective Our objective was to study the radiation exposure rate as function of time in the administration of radioiodine iodine-131 (I-131) for the treatment of thyrotoxicosis or Graves' disease and remnant ablation on an outpatient basis at the Department of Nuclear Medicine, and also, to study the impact of revised discharge criteria for radioiodine therapy enforced by the Atomic Energy Regulatory Board (AERB) of India. Materials and Methods This study included patients who underwent low-dose radioiodine therapy using I-131. Patients were classified into two different groups, that is, group A and group B. Group A included patients receiving low dose I-131 for the treatment of thyrotoxicosis, whereas group B included patients receiving I-131 therapy for the ablation of residual thyroid tissue after total thyroidectomy. The radiation exposure rate was measured using a radiation detector in milli roentgen per hour (mR/h) at 5 cm distance of stomach and neck levels and with the patient standing at the distance of 1 m after oral administration of I-131 at 0, 1, and 2 hours. Results A total of 134 (17 males and 117 females) patients were included in the study. Group A comprised 102 (14 male and 88 females) patients and group B of 32 (3 males and 29 females) patients. At the neck level, the average exposure rate in group A versus group B after 0, 1, and 2 hours was observed to be 6.9 versus 22.27 mR/h, 33.67 versus 43.39 mR/h, and 41.75 versus 48.90 mR/h, respectively. At the stomach level, the exposure rate was 23.65 versus 71.32 mR/h, 13.27 versus 48.45 mR/h, and 9.91 versus 39.43 mR/h after 0, 1, and 2 hours, respectively. At a distance of 1 m, the exposure rate was 1.31 versus 2.99 mR/h, 1.05 versus 2.58 mR/h, and 0.92 versus 2.21 mR/h, respectively. Conclusion Exposure rate measured for patients treated with up to 1,110 MBq (30 mCi) of I-131 was under permissible limits as per revised discharged limits, that is, 50 µSv/h (5 mR/h) prescribed by AERB, India. The patients undergoing radioiodine therapy I-131 (up to 1,110 MBq/30 mCi) can be discharged safely 2 hours postadministration following good work practice along with providing proper radiation safety instructions to patients.
{"title":"Radiation Safety and External Radiation Exposure Rate of Patients Receiving I-131 Therapy for Hyperthyroidism and Remnant Ablation as Outpatient: An Institutional Experience","authors":"Nisha Bhatia, Vandana K. Dhingra, Pulkit Mittal, Sunil Saini","doi":"10.1055/s-0043-1771285","DOIUrl":"https://doi.org/10.1055/s-0043-1771285","url":null,"abstract":"Abstract Objective Our objective was to study the radiation exposure rate as function of time in the administration of radioiodine iodine-131 (I-131) for the treatment of thyrotoxicosis or Graves' disease and remnant ablation on an outpatient basis at the Department of Nuclear Medicine, and also, to study the impact of revised discharge criteria for radioiodine therapy enforced by the Atomic Energy Regulatory Board (AERB) of India. Materials and Methods This study included patients who underwent low-dose radioiodine therapy using I-131. Patients were classified into two different groups, that is, group A and group B. Group A included patients receiving low dose I-131 for the treatment of thyrotoxicosis, whereas group B included patients receiving I-131 therapy for the ablation of residual thyroid tissue after total thyroidectomy. The radiation exposure rate was measured using a radiation detector in milli roentgen per hour (mR/h) at 5 cm distance of stomach and neck levels and with the patient standing at the distance of 1 m after oral administration of I-131 at 0, 1, and 2 hours. Results A total of 134 (17 males and 117 females) patients were included in the study. Group A comprised 102 (14 male and 88 females) patients and group B of 32 (3 males and 29 females) patients. At the neck level, the average exposure rate in group A versus group B after 0, 1, and 2 hours was observed to be 6.9 versus 22.27 mR/h, 33.67 versus 43.39 mR/h, and 41.75 versus 48.90 mR/h, respectively. At the stomach level, the exposure rate was 23.65 versus 71.32 mR/h, 13.27 versus 48.45 mR/h, and 9.91 versus 39.43 mR/h after 0, 1, and 2 hours, respectively. At a distance of 1 m, the exposure rate was 1.31 versus 2.99 mR/h, 1.05 versus 2.58 mR/h, and 0.92 versus 2.21 mR/h, respectively. Conclusion Exposure rate measured for patients treated with up to 1,110 MBq (30 mCi) of I-131 was under permissible limits as per revised discharged limits, that is, 50 µSv/h (5 mR/h) prescribed by AERB, India. The patients undergoing radioiodine therapy I-131 (up to 1,110 MBq/30 mCi) can be discharged safely 2 hours postadministration following good work practice along with providing proper radiation safety instructions to patients.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47601736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Intrathecal administration of radiopharmaceuticals is an infrequently performed procedure in most nuclear medicine facilities. It is possible that adverse allergic reactions following the intrathecal administration of radiopharmaceuticals often go unreported. Here we present a case of spontaneous cerebrospinal fluid rhinorrhea with recurrent bacterial meningitis, who underwent radionuclide cisternography for localization of the site of leak and developed an adverse allergic reaction following the intrathecal administration of technetium-99m diethylenetriamine pentaacetate that resolved with appropriate treatment. Imaging, however, could be carried out to our satisfaction and the allergic reaction did not interfere with, or result in discontinuation of the scan procedure.
{"title":"Adverse Allergic Reaction to Intrathecally Administered Technetium-99m Diethylenetriamine Pentaacetate: A Case Report","authors":"Ahalya Nair, Guneshwaran Poolpandian, Kabilash Dhayalan, Jayaram Saibaba","doi":"10.1055/s-0043-1771281","DOIUrl":"https://doi.org/10.1055/s-0043-1771281","url":null,"abstract":"Abstract Intrathecal administration of radiopharmaceuticals is an infrequently performed procedure in most nuclear medicine facilities. It is possible that adverse allergic reactions following the intrathecal administration of radiopharmaceuticals often go unreported. Here we present a case of spontaneous cerebrospinal fluid rhinorrhea with recurrent bacterial meningitis, who underwent radionuclide cisternography for localization of the site of leak and developed an adverse allergic reaction following the intrathecal administration of technetium-99m diethylenetriamine pentaacetate that resolved with appropriate treatment. Imaging, however, could be carried out to our satisfaction and the allergic reaction did not interfere with, or result in discontinuation of the scan procedure.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45986712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Urethral melanomas are a rare subtype of noncutaneous melanomas. The disease has a tendency to have skip lesions and early metastases as compared with cutaneous melanomas. The role of fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography computed tomography (PET-CT) is well established in cases of cutaneous melanomas and is recommended by the National Comprehensive Cancer Network (NCCN) for stage IIB to IV cancer. There are no established guidelines on the management of noncutaneous melanomas; however, a recently published United Kingdom national guideline aims to streamline the management of ano-uro-genital melanomas. The guideline describes a very limited role in the use of 18 F-FDG PET-CT in this case scenario. The tendency to skip lesions, early metastases, involvement of brain parenchyma, and finally the usage of anti-PD-1 medications are key areas where 18 F-FDG PET-CT has shown superiority over CT scan. With this case report, we aim to highlight the strength of 18 F-FDG PET-CT in the management of urethral melanomas, which can be extrapolated to other ano-uro-genital melanomas.
{"title":"Role of 18 F-FDG PET-CT in Urethral Malignant Melanoma and Analysis of the UK Guidelines on Ano-uro-genital Melanomas","authors":"Abhishek Mahato, Anurag Jain, M.G. Manoj, Richa Joshi","doi":"10.1055/s-0043-1771280","DOIUrl":"https://doi.org/10.1055/s-0043-1771280","url":null,"abstract":"Abstract Urethral melanomas are a rare subtype of noncutaneous melanomas. The disease has a tendency to have skip lesions and early metastases as compared with cutaneous melanomas. The role of fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography computed tomography (PET-CT) is well established in cases of cutaneous melanomas and is recommended by the National Comprehensive Cancer Network (NCCN) for stage IIB to IV cancer. There are no established guidelines on the management of noncutaneous melanomas; however, a recently published United Kingdom national guideline aims to streamline the management of ano-uro-genital melanomas. The guideline describes a very limited role in the use of 18 F-FDG PET-CT in this case scenario. The tendency to skip lesions, early metastases, involvement of brain parenchyma, and finally the usage of anti-PD-1 medications are key areas where 18 F-FDG PET-CT has shown superiority over CT scan. With this case report, we aim to highlight the strength of 18 F-FDG PET-CT in the management of urethral melanomas, which can be extrapolated to other ano-uro-genital melanomas.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":"352 ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41272306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Al-Fatlawi, Farideh Pak, Saeed Farzanefar, Yalda Salehi, Abbas Monsef, P. Sheikhzadeh
Abstract: Background This study was aimed to optimize the fluorodeoxyglucose (FDG)-administered dose and scan time based on patient specifications using a highly sensitive five-ring bismuth germanium oxide (BGO)-based positron emission tomography/computed tomography (PET/CT) scanner (Discovery IQ). Methods We retrospectively analyzed 101 whole-body 18 F-FDG PET/CT images. Patient data were reconstructed using ordered subset expectation maximization with resolution recovery algorithms (OSEM + SharpIR). Signal-to-noise ratio (SNR) was calculated for each patient, standardized to SNR norm , and plotted against three body index parameters (weight, body mass index, and lean body mass). Two professional physicians blindly examined image quality at different patient time per bed positions to determine the minimum acceptable quality. To select images of acceptable quality, the noise index parameter was also measured. A new dose-time product (DTP) was established for each patient, and a predicted injected dose was assumed. Results We found an almost linear association between patient weight and normalized SNR, and patient weight had the highest R 2 in the fitting. The redesigned DTP can reduce results by approximately 74 and 38% compared with ordinary DTP for 80- and 160-s scan durations. The new dose regimen formula was found to be DTP = c/t × m 1.24 , where m is the patient weight, t is the scan time per bed position, and c is 1.8 and 4.3 for acceptable and higher confidence states, respectively, in Discovery IQ PET/CT. Conclusion Patient weight is the best clinical parameter for the implementation of 18 F-FDG PET/CT image quality assessment. A new dose-time regimen based on body weight was proposed for use in highly sensitive five-ring BGO PET-CT scanners to significantly reduce the injection dose and scan times while maintaining sufficient image quality for diagnosis.
摘要：背景 本研究旨在使用基于高灵敏度五环氧化铋锗（BGO）的正电子发射断层扫描/计算机断层扫描（PET/CT）扫描仪（Discovery IQ），根据患者规格优化氟脱氧葡萄糖（FDG）的给药剂量和扫描时间。方法 我们回顾性分析了101例全身18F-FDG PET/CT图像。使用有序子集期望最大化和分辨率恢复算法（OSEM+SharpIR）重建患者数据。计算每个患者的信噪比（SNR），标准化为SNR标准，并根据三个身体指数参数（体重、体重指数和瘦体重）绘制。两位专业医生盲目地检查了每个床位不同患者时间的图像质量，以确定可接受的最低质量。为了选择质量可接受的图像，还测量了噪声指数参数。为每位患者建立新的剂量-时间乘积（DTP），并假设预测的注射剂量。后果 我们发现患者体重和归一化SNR之间几乎呈线性关系，并且患者体重在拟合中具有最高的R2。与普通DTP相比，在80秒和160秒的扫描持续时间内，重新设计的DTP可以将结果减少约74%和38%。新的给药方案是DTP = c/t × m 1.24，其中m是患者体重，t是每个床位的扫描时间，对于Discovery IQ PET/CT中的可接受和较高置信度状态，c分别为1.8和4.3。结论 患者体重是实施18F-FDG PET/CT图像质量评估的最佳临床参数。提出了一种基于体重的新剂量-时间方案，用于高灵敏度的五环BGO PET-CT扫描仪，以显著减少注射剂量和扫描时间，同时保持足够的诊断图像质量。
{"title":"Optimization of the Acquisition Time and Injected Dose of 18 F-Fluorodeoxyglucose Based on Patient Specifications for High-Sensitive Positron Emission Tomography/Computed Tomography Scanner","authors":"M. Al-Fatlawi, Farideh Pak, Saeed Farzanefar, Yalda Salehi, Abbas Monsef, P. Sheikhzadeh","doi":"10.1055/s-0043-1771284","DOIUrl":"https://doi.org/10.1055/s-0043-1771284","url":null,"abstract":"Abstract: Background This study was aimed to optimize the fluorodeoxyglucose (FDG)-administered dose and scan time based on patient specifications using a highly sensitive five-ring bismuth germanium oxide (BGO)-based positron emission tomography/computed tomography (PET/CT) scanner (Discovery IQ). Methods We retrospectively analyzed 101 whole-body 18 F-FDG PET/CT images. Patient data were reconstructed using ordered subset expectation maximization with resolution recovery algorithms (OSEM + SharpIR). Signal-to-noise ratio (SNR) was calculated for each patient, standardized to SNR norm , and plotted against three body index parameters (weight, body mass index, and lean body mass). Two professional physicians blindly examined image quality at different patient time per bed positions to determine the minimum acceptable quality. To select images of acceptable quality, the noise index parameter was also measured. A new dose-time product (DTP) was established for each patient, and a predicted injected dose was assumed. Results We found an almost linear association between patient weight and normalized SNR, and patient weight had the highest R 2 in the fitting. The redesigned DTP can reduce results by approximately 74 and 38% compared with ordinary DTP for 80- and 160-s scan durations. The new dose regimen formula was found to be DTP = c/t × m 1.24 , where m is the patient weight, t is the scan time per bed position, and c is 1.8 and 4.3 for acceptable and higher confidence states, respectively, in Discovery IQ PET/CT. Conclusion Patient weight is the best clinical parameter for the implementation of 18 F-FDG PET/CT image quality assessment. A new dose-time regimen based on body weight was proposed for use in highly sensitive five-ring BGO PET-CT scanners to significantly reduce the injection dose and scan times while maintaining sufficient image quality for diagnosis.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47130800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Venous tumor thrombus is a rare complication of rectal cancer but is more common in other types of cancer, like renal cell carcinoma and hepatocellular carcinoma. The usual site of tumor thrombus in rectal cancer patients is the inferior mesenteric vein (IMV), which is seldom seen in the common iliac vein, with only a few cases reported till now. We present a case of fluorodeoxyglucose (FDG) avid right iliac vein tumor thrombosis after low anterior resection in a patient with rectal cancer and review the literature.
{"title":"FDG PET/CT Depicting Right Iliac Vein Tumor Thrombosis following Low Anterior Resection in Rectal Cancer Patient: A Case Report and Literature Review","authors":"Akram Al-Ibraheem, Serin Moghrabi","doi":"10.1055/s-0043-1771288","DOIUrl":"https://doi.org/10.1055/s-0043-1771288","url":null,"abstract":"Abstract Venous tumor thrombus is a rare complication of rectal cancer but is more common in other types of cancer, like renal cell carcinoma and hepatocellular carcinoma. The usual site of tumor thrombus in rectal cancer patients is the inferior mesenteric vein (IMV), which is seldom seen in the common iliac vein, with only a few cases reported till now. We present a case of fluorodeoxyglucose (FDG) avid right iliac vein tumor thrombosis after low anterior resection in a patient with rectal cancer and review the literature.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42561427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abhishek Mahato, Anurag Jain, V.S Prakash, Rajesh Nair, Richa Joshi, D. Paliwal, Awadhesh Tiwari, S. Khandpur, Harkirat Singh
Abstract Background Flourine-18 fluorodeoxyglucose positron emission tomography-computed tomography ( 18 F-FDG PET-CT) is a well-established imaging modality for the evaluation of patients with oncological and nononcological conditions. The underlying principle of imaging is the preferentially increased glucose consumption by cancer cells, due to overexpression of glucose type 1 receptors that are insulin independent. Thus, one of the factors that leads to decreased sensitivity of an 18 F-FDG PET-CT is elevated blood sugar levels, leading to decreased glucose uptake by cancer cells due to competitive inhibition. A significant percentage of patients scheduled for PET-CT scan has diabetes mellitus type II as a comorbid condition and often has elevated random blood sugar (RBS) precluding an upfront PET-CT evaluation. Such cases must be rescheduled. This causes delay in the evaluation and management of such patients. Empagliflozin is a novel sodium glucose type 2 inhibitor that prevents tubular reabsorption of glucose and increases renal glycosuria resulting in decreased blood sugar. This drug does not cause significant hypoglycemia or increase endogenous insulin secretion. This study was undertaken to evaluate a potential role for empagliflozin in facilitating optimal blood sugar control in patients with hyperglycemia on the day of the scheduled PET scan. Methods This is an interventional prospective study and patients detected to have RBS more than 200 mg/dL on the day of the scheduled scan were included in the study. The patients were administered two tablets of 10 mg empagliflozin and kept under observation. Samples for RBS were taken at approximately 2nd and 4th hour post administration by bedside method. These patients underwent scan on the same day after adequate sugar control and when an RBS of less than 200 mg/dL was achieved. The primary outcome studied was change in RBS values in the patient cohort and evaluation of PET SUV (standardized uptake value) compared with the rest of the patients scheduled on the same day. Secondary outcome was assessment of any side effects in the patients. Results Total of 10 patients were found to have elevated blood sugar (RBS > 200 mg/dL; irrespective of being on medication) and did not meet the evaluation criteria for a PET-CT scan on the scheduled day. Following administration of the drug, all 10 patients were able to attain blood sugar levels and fulfill the criteria for undergoing a PET-CT scan. No obvious side effect was noted in any of the patient. The SUV values of the patient cohort were comparable with the rest of the patient scanned on the day. Conclusion In this pilot study, 20 mg of empagliflozin (2 tablets of 10 mg) appears to be a safe and effective method for achieving optimal decrease in the RBS without causing hypoglycemia or hyperinsulinemia. It can be safely employed in the subset of population with RBS between 201 and 300 mg/dL to adequately bring the sugar levels at acceptable levels
{"title":"Use of Oral Empagliflozin to Obtain Optimal Blood Sugar Levels for Conducting 18 F-FDG PET-CT in Patients with Hyperglycemia—A Pilot Study","authors":"Abhishek Mahato, Anurag Jain, V.S Prakash, Rajesh Nair, Richa Joshi, D. Paliwal, Awadhesh Tiwari, S. Khandpur, Harkirat Singh","doi":"10.1055/s-0043-1771283","DOIUrl":"https://doi.org/10.1055/s-0043-1771283","url":null,"abstract":"Abstract Background Flourine-18 fluorodeoxyglucose positron emission tomography-computed tomography ( 18 F-FDG PET-CT) is a well-established imaging modality for the evaluation of patients with oncological and nononcological conditions. The underlying principle of imaging is the preferentially increased glucose consumption by cancer cells, due to overexpression of glucose type 1 receptors that are insulin independent. Thus, one of the factors that leads to decreased sensitivity of an 18 F-FDG PET-CT is elevated blood sugar levels, leading to decreased glucose uptake by cancer cells due to competitive inhibition. A significant percentage of patients scheduled for PET-CT scan has diabetes mellitus type II as a comorbid condition and often has elevated random blood sugar (RBS) precluding an upfront PET-CT evaluation. Such cases must be rescheduled. This causes delay in the evaluation and management of such patients. Empagliflozin is a novel sodium glucose type 2 inhibitor that prevents tubular reabsorption of glucose and increases renal glycosuria resulting in decreased blood sugar. This drug does not cause significant hypoglycemia or increase endogenous insulin secretion. This study was undertaken to evaluate a potential role for empagliflozin in facilitating optimal blood sugar control in patients with hyperglycemia on the day of the scheduled PET scan. Methods This is an interventional prospective study and patients detected to have RBS more than 200 mg/dL on the day of the scheduled scan were included in the study. The patients were administered two tablets of 10 mg empagliflozin and kept under observation. Samples for RBS were taken at approximately 2nd and 4th hour post administration by bedside method. These patients underwent scan on the same day after adequate sugar control and when an RBS of less than 200 mg/dL was achieved. The primary outcome studied was change in RBS values in the patient cohort and evaluation of PET SUV (standardized uptake value) compared with the rest of the patients scheduled on the same day. Secondary outcome was assessment of any side effects in the patients. Results Total of 10 patients were found to have elevated blood sugar (RBS > 200 mg/dL; irrespective of being on medication) and did not meet the evaluation criteria for a PET-CT scan on the scheduled day. Following administration of the drug, all 10 patients were able to attain blood sugar levels and fulfill the criteria for undergoing a PET-CT scan. No obvious side effect was noted in any of the patient. The SUV values of the patient cohort were comparable with the rest of the patient scanned on the day. Conclusion In this pilot study, 20 mg of empagliflozin (2 tablets of 10 mg) appears to be a safe and effective method for achieving optimal decrease in the RBS without causing hypoglycemia or hyperinsulinemia. It can be safely employed in the subset of population with RBS between 201 and 300 mg/dL to adequately bring the sugar levels at acceptable levels","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45304706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maryam Darami, B. Mahmoudian, Michael Ljungberg, Jalil Pirayesh Islamian
Abstract Objectives Collimators have a significant role in image quality and detectability in single-photon emission computed tomography (SPECT) imaging. Using an appropriate alloy that effectively absorbs scattered photons, without induced secondary x-rays, and with proper rigidity and weight may provide an effective approach to the image improvement that conventionally collimators made of lead (Pb). Materials and Methods A Siemens E.CAM SPECT imaging system equipped with low-energy high-resolution (LEHR) collimator was simulated by the Simulating Medical Imaging Nuclear Detectors Monte Carlo program. Experimental and simulated data were compared based on a 2-mm 99m Tc point source in an acrylic cylindrical Deluxe phantom (Data Spectrum, Inc). Seven types of tungsten (W) alloys (Wolfmet), with W content from 90 to 97% by weight, were then used as collimator materials of the simulated system. Camera parameters, such as energy- and spatial resolution, image contrast, and collimator-related parameters, such as fraction of septal penetration, scatter-to-primary ratios, and percentage of induced secondary x-rays, due to interactions in the collimator, were evaluated. Results Acceptable conformity was found for the simulated and experiment systems in terms of energy spectra, 10.113 and 10.140%, full width at half-maximum (FWHM) of the point spread function (PSF) curves, 8.78 and 9.06 mm, sensitivity, 78.46 and 78.34 cps/MBq, and contrast in images of 19.1 mm cold spheres in the Deluxe phantom, 79.17 and 78.97%, respectively. Results on the parameters of the simulated system with LEHR collimator made from the alloys showed that the alloy consisting of 90% W, 6% nickel, and 4% copper provided an FWHM of 8.76 mm, resulting in a 0.2% improvement in spatial resolution. Furthermore, all the Wolfmet collimators showed a 48% reduction in the amount of X-rays production compared to the Pb. Conclusion A Wolfmet LEHR collimator, made by a combination of W (90%), Ni (6%), and Cu (6%) provides a better image quality and detectability compared to the Pb.
{"title":"Impact of Wolfmet Tungsten Alloys as Parallel-Hole Collimator Material on Single-Photon Emission Computed Tomography Image Quality and Functional Parameters: A Simulating Medical Imaging Nuclear Detectors Monte Carlo Study","authors":"Maryam Darami, B. Mahmoudian, Michael Ljungberg, Jalil Pirayesh Islamian","doi":"10.1055/s-0043-1771287","DOIUrl":"https://doi.org/10.1055/s-0043-1771287","url":null,"abstract":"Abstract Objectives Collimators have a significant role in image quality and detectability in single-photon emission computed tomography (SPECT) imaging. Using an appropriate alloy that effectively absorbs scattered photons, without induced secondary x-rays, and with proper rigidity and weight may provide an effective approach to the image improvement that conventionally collimators made of lead (Pb). Materials and Methods A Siemens E.CAM SPECT imaging system equipped with low-energy high-resolution (LEHR) collimator was simulated by the Simulating Medical Imaging Nuclear Detectors Monte Carlo program. Experimental and simulated data were compared based on a 2-mm 99m Tc point source in an acrylic cylindrical Deluxe phantom (Data Spectrum, Inc). Seven types of tungsten (W) alloys (Wolfmet), with W content from 90 to 97% by weight, were then used as collimator materials of the simulated system. Camera parameters, such as energy- and spatial resolution, image contrast, and collimator-related parameters, such as fraction of septal penetration, scatter-to-primary ratios, and percentage of induced secondary x-rays, due to interactions in the collimator, were evaluated. Results Acceptable conformity was found for the simulated and experiment systems in terms of energy spectra, 10.113 and 10.140%, full width at half-maximum (FWHM) of the point spread function (PSF) curves, 8.78 and 9.06 mm, sensitivity, 78.46 and 78.34 cps/MBq, and contrast in images of 19.1 mm cold spheres in the Deluxe phantom, 79.17 and 78.97%, respectively. Results on the parameters of the simulated system with LEHR collimator made from the alloys showed that the alloy consisting of 90% W, 6% nickel, and 4% copper provided an FWHM of 8.76 mm, resulting in a 0.2% improvement in spatial resolution. Furthermore, all the Wolfmet collimators showed a 48% reduction in the amount of X-rays production compared to the Pb. Conclusion A Wolfmet LEHR collimator, made by a combination of W (90%), Ni (6%), and Cu (6%) provides a better image quality and detectability compared to the Pb.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45080482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Habibollah Dadgar, M. S. Vafaee, Amirreza Khorasanchi, Parastoo Kordestani Moghadam, Reza Nemati, Hossein Shooli, Esmail Jafari, Majid Assadi
Abstract Background An accurate monitoring technique is crucial in brain tumors to choose the best treatment approach after surgery and/or chemoradiation. Radiological assessment of brain tumors is widely based on the magnetic resonance imaging (MRI) modality in this regard; however, MRI criteria are unable to precisely differentiate tumoral tissue from treatment-related changes. This study was conducted to evaluate whether fused MRI and O-(2- 18 F-fluoroethyl)-L-tyrosine ( 18 F-FET) positron emission tomography (PET) can improve the diagnostic accuracy of the practitioners to discriminate treatment-related changes from true recurrence of brain tumor. Methods We retrospectively analyzed 18 F-FET PET/computed tomography (CT) of 11 patients with histopathologically proven brain tumors that were suspicious for recurrence changes after 3 to 4 months of surgery. All the patients underwent MRI and 18 F-FET PET/CT. As a third assessment, fused 18 F-FET PET/MRI was also acquired. Finally, the diagnostic accuracy of the applied modalities was compared. Results Eleven patients aged 27 to 73 years with a mean age of 47 ± 13 years were enrolled. According to the results, 9/11 cases (82%) showed positive MRI and 6 cases (55%) showed positive PET/CT and PET/MRI. Tumoral recurrence was observed in six patients (55%) in the follow-up period. Based on the follow-up results, accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 64, 85, 25, 67, and 50%, respectively, for MRI alone and 91, 85, 100, 100, and 80%, respectively, for both PET/CT and PET/MRI. Conclusion This study found that 18 F-FET PET-MR image fusion in the management of brain tumors might improve recurrence detection; however, further well-designed studies are needed to verify these preliminary data.
{"title":"Initial Experience of 18 F-FET PET-MR Image Fusion for Evaluation of Recurrent Primary Brain Tumors","authors":"Habibollah Dadgar, M. S. Vafaee, Amirreza Khorasanchi, Parastoo Kordestani Moghadam, Reza Nemati, Hossein Shooli, Esmail Jafari, Majid Assadi","doi":"10.1055/s-0043-1771282","DOIUrl":"https://doi.org/10.1055/s-0043-1771282","url":null,"abstract":"Abstract Background An accurate monitoring technique is crucial in brain tumors to choose the best treatment approach after surgery and/or chemoradiation. Radiological assessment of brain tumors is widely based on the magnetic resonance imaging (MRI) modality in this regard; however, MRI criteria are unable to precisely differentiate tumoral tissue from treatment-related changes. This study was conducted to evaluate whether fused MRI and O-(2- 18 F-fluoroethyl)-L-tyrosine ( 18 F-FET) positron emission tomography (PET) can improve the diagnostic accuracy of the practitioners to discriminate treatment-related changes from true recurrence of brain tumor. Methods We retrospectively analyzed 18 F-FET PET/computed tomography (CT) of 11 patients with histopathologically proven brain tumors that were suspicious for recurrence changes after 3 to 4 months of surgery. All the patients underwent MRI and 18 F-FET PET/CT. As a third assessment, fused 18 F-FET PET/MRI was also acquired. Finally, the diagnostic accuracy of the applied modalities was compared. Results Eleven patients aged 27 to 73 years with a mean age of 47 ± 13 years were enrolled. According to the results, 9/11 cases (82%) showed positive MRI and 6 cases (55%) showed positive PET/CT and PET/MRI. Tumoral recurrence was observed in six patients (55%) in the follow-up period. Based on the follow-up results, accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 64, 85, 25, 67, and 50%, respectively, for MRI alone and 91, 85, 100, 100, and 80%, respectively, for both PET/CT and PET/MRI. Conclusion This study found that 18 F-FET PET-MR image fusion in the management of brain tumors might improve recurrence detection; however, further well-designed studies are needed to verify these preliminary data.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":"22 1","pages":"183 - 190"},"PeriodicalIF":0.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48191476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Madhur K. Srivastava, Afshan J. Shaik, Sireesha Yareeda, Kavitha Nallapareddy, L. Lingappa, Pallavi Moturi, Padmaja Gaddamonugu, R. M. Kandadai, R. Borgohain
Abstract Objective Electrical status epilepticus in sleep (ESES) is defined by near-continuous epileptiform discharges during sleep along with cognitive, behavioral, and/or imaging abnormalities. We studied the neurocognitive profile and their correlation with 18 F fluorodeoxyglucose positron emission tomography (FDG PET) brain abnormalities in children with ESES. Methods Fourteen children with ESES with normal magnetic resonance imaging (MRI) from March to December 2019 were included. The intelligence quotient (IQ) and child behavior checklist (CBCL) scores were estimated using validated scales, and FDG PET brain was done at the same point of time to look for cerebral metabolic defects which was compared with a control group. Results Fourteen patients with a mean age of 8.2 ± 2.7 years were analyzed. The average duration of epilepsy was 6 ± 2.8 years. The mean IQ was 72.4 ± 18.2 and mean CBCL score was 37.3 ± 11.8. There was negative correlation between IQ and CBCL ( r = −0.55, p < 0.001). The duration of epilepsy also showed negative correlation with IQ ( r = −4.75, p < 0.001). FDG PET scan showed predominant thalamic hypometabolism in 12 of 14 patients (85.7%) on visual analysis with multiple other hypometabolic cortical and subcortical regions in the brain. The quantitative analysis showed significant difference in metabolism of basal ganglion when compared with control group. The total number of hypometabolic regions seen in the brain showed moderate positive correlation with CBCL score but no significant correlation with the IQ of cases. Conclusion This study demonstrates functional impairment of cerebral cortical, basal ganglia, and thalamic hypometabolism in a cohort of ESES patients with normal structural MRI brain study. There was a moderate correlation of extent and pattern of cerebral hypometabolism with the neuropsychological status of the child and duration of epilepsy.
{"title":"Neurocognitive Profile and 18 F-Fluorodeoxyglucose Positron Emission Tomography Brain Imaging Correlation in Children with Electrical Status Epilepticus during Sleep","authors":"Madhur K. Srivastava, Afshan J. Shaik, Sireesha Yareeda, Kavitha Nallapareddy, L. Lingappa, Pallavi Moturi, Padmaja Gaddamonugu, R. M. Kandadai, R. Borgohain","doi":"10.1055/s-0042-1757284","DOIUrl":"https://doi.org/10.1055/s-0042-1757284","url":null,"abstract":"Abstract Objective Electrical status epilepticus in sleep (ESES) is defined by near-continuous epileptiform discharges during sleep along with cognitive, behavioral, and/or imaging abnormalities. We studied the neurocognitive profile and their correlation with 18 F fluorodeoxyglucose positron emission tomography (FDG PET) brain abnormalities in children with ESES. Methods Fourteen children with ESES with normal magnetic resonance imaging (MRI) from March to December 2019 were included. The intelligence quotient (IQ) and child behavior checklist (CBCL) scores were estimated using validated scales, and FDG PET brain was done at the same point of time to look for cerebral metabolic defects which was compared with a control group. Results Fourteen patients with a mean age of 8.2 ± 2.7 years were analyzed. The average duration of epilepsy was 6 ± 2.8 years. The mean IQ was 72.4 ± 18.2 and mean CBCL score was 37.3 ± 11.8. There was negative correlation between IQ and CBCL ( r = −0.55, p < 0.001). The duration of epilepsy also showed negative correlation with IQ ( r = −4.75, p < 0.001). FDG PET scan showed predominant thalamic hypometabolism in 12 of 14 patients (85.7%) on visual analysis with multiple other hypometabolic cortical and subcortical regions in the brain. The quantitative analysis showed significant difference in metabolism of basal ganglion when compared with control group. The total number of hypometabolic regions seen in the brain showed moderate positive correlation with CBCL score but no significant correlation with the IQ of cases. Conclusion This study demonstrates functional impairment of cerebral cortical, basal ganglia, and thalamic hypometabolism in a cohort of ESES patients with normal structural MRI brain study. There was a moderate correlation of extent and pattern of cerebral hypometabolism with the neuropsychological status of the child and duration of epilepsy.","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43670682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lu-DOTATATE, a peptide receptor-based radionuclide therapy (PRRT), is one of latest treatment options for patients with progressive gastro-entero-pancreatic neuroendocrine tumors (NETs) and leads to significantly better disease-free survival.1 Although rare, an ominous adverse effect seen with PRRT is development of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Recently, a global multicenter study done by Vigne et al using the World Health Organization pharmacovigilance database VigiBase including 1,674 cases, showed0.91 and0.31% incidence ofMDSandAML, respectively. These adverse events were associated with treatment discontinuation in all affected patients, andmore importantly approximatelyone-third of these cases eventually had fatal outcomes.2 Based on accumulated clinical data over the past decade and a half, incidence of PRRT-relatedmyeloid neoplasms (t-MN) has been reported in 0.2 to 5.4% of the patients.3–6 Long-term follow-up data from Erasmus Medical Centre, including 1,214 patients showed MDS incidence at 1.5% after a median followup of 28 months and acute leukemia at 0.7% after a median follow-up of 55 months after first therapy.7 The final results of theNETTER-1studygroupshowedt-MNriskat1.2%post5years of the last patient is randomized.8 A slightly higher percentage of patients experienced t-MN after PRRT in two other studies, both of which combined PRRT with prior or concomitant chemotherapy. Of note, a much higher rate of t-MN (20%) was reported by Brieau et al in a limited series of 20 nonresectable NETs treated with Lu-PPRT after heavy pretreatment with chemotherapy.9Another studydonebyGoncalves et al from the Peter MacCallum Cancer center including 521 patients over a 12-year period showed 4.8% incidence of t-MN.10 Twenty-five percent of these patients had receivedprior chemotherapywith carboplatin/etoposide and 88% received concomitant radiosensitizing chemotherapy such as 5FU or capecitabine. Themedian overall survival (OS) after diagnosis of t-MN was shown to be mere 13 months. Although the novel approach of PRRT with combined chemotherapy may potentially offer better tumor control, it may also slightly augment the risk of t-MN. The quest for identifying predictive biomarkers for post-tMN continues. Unlike nephrotoxicitywhich is considered dosedependent side effect of PRRT, occurrence of long-term hematological toxicity is difficult to predict based onmarrow dosimetryalone.11AstudydonebyBrieauetal showedtwoprognostic factors for the development of t-MN identified in this study: (1) early grade 3 to 4 hematological toxicity after PRRT and (2) higher number of chemotherapy cycles before PRRT. Similarly, post-PRRT thrombocytopenia was significantly related to the development of secondary MDS or AML in a previous study.5 Hence, close monitoring should be recommended in patients experiencing early hematological toxicity after PRRT. A novel strategy to mitigate the risk of t-MN appears to be pretreatment identificat
{"title":"Screening for Clonal Hematopoiesis for Mitigating the Risk of Hematopoietic Neoplasms after PRRT.","authors":"Piyush Chandra, Kishore Kumar","doi":"10.1055/s-0043-1764308","DOIUrl":"https://doi.org/10.1055/s-0043-1764308","url":null,"abstract":"Lu-DOTATATE, a peptide receptor-based radionuclide therapy (PRRT), is one of latest treatment options for patients with progressive gastro-entero-pancreatic neuroendocrine tumors (NETs) and leads to significantly better disease-free survival.1 Although rare, an ominous adverse effect seen with PRRT is development of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Recently, a global multicenter study done by Vigne et al using the World Health Organization pharmacovigilance database VigiBase including 1,674 cases, showed0.91 and0.31% incidence ofMDSandAML, respectively. These adverse events were associated with treatment discontinuation in all affected patients, andmore importantly approximatelyone-third of these cases eventually had fatal outcomes.2 Based on accumulated clinical data over the past decade and a half, incidence of PRRT-relatedmyeloid neoplasms (t-MN) has been reported in 0.2 to 5.4% of the patients.3–6 Long-term follow-up data from Erasmus Medical Centre, including 1,214 patients showed MDS incidence at 1.5% after a median followup of 28 months and acute leukemia at 0.7% after a median follow-up of 55 months after first therapy.7 The final results of theNETTER-1studygroupshowedt-MNriskat1.2%post5years of the last patient is randomized.8 A slightly higher percentage of patients experienced t-MN after PRRT in two other studies, both of which combined PRRT with prior or concomitant chemotherapy. Of note, a much higher rate of t-MN (20%) was reported by Brieau et al in a limited series of 20 nonresectable NETs treated with Lu-PPRT after heavy pretreatment with chemotherapy.9Another studydonebyGoncalves et al from the Peter MacCallum Cancer center including 521 patients over a 12-year period showed 4.8% incidence of t-MN.10 Twenty-five percent of these patients had receivedprior chemotherapywith carboplatin/etoposide and 88% received concomitant radiosensitizing chemotherapy such as 5FU or capecitabine. Themedian overall survival (OS) after diagnosis of t-MN was shown to be mere 13 months. Although the novel approach of PRRT with combined chemotherapy may potentially offer better tumor control, it may also slightly augment the risk of t-MN. The quest for identifying predictive biomarkers for post-tMN continues. Unlike nephrotoxicitywhich is considered dosedependent side effect of PRRT, occurrence of long-term hematological toxicity is difficult to predict based onmarrow dosimetryalone.11AstudydonebyBrieauetal showedtwoprognostic factors for the development of t-MN identified in this study: (1) early grade 3 to 4 hematological toxicity after PRRT and (2) higher number of chemotherapy cycles before PRRT. Similarly, post-PRRT thrombocytopenia was significantly related to the development of secondary MDS or AML in a previous study.5 Hence, close monitoring should be recommended in patients experiencing early hematological toxicity after PRRT. A novel strategy to mitigate the risk of t-MN appears to be pretreatment identificat","PeriodicalId":23742,"journal":{"name":"World Journal of Nuclear Medicine","volume":"22 2","pages":"150-151"},"PeriodicalIF":0.6,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10202583/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9888128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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