Pub Date : 2019-04-16DOI: 10.4172/2155-9619.1000401
Osama H Elzaafarany, E. Ali, S. Fadel, A. Kandil
Adjuvant radiotherapy is an integral part of breast cancer treatment, and there was a great evolution of radiotherapy techniques over the past few years. Intensity-modulated radiation therapy (IMRT) was developed in the 1990s as a modern technique aiming to spare normal tissues from toxic effects of radiotherapy. This study aimed at comparing the IMRT technique to the 3D-coformal radiotherapy technique (3D-CRT) in early breast cancer patients regarding the occurrence of acute skin toxicities and treatment-related lymphopenia (TRL). It is a prospective study conducted on 100 eligible patients who were divided equally between two groups; the first, are patients received adjuvant radiotherapy using IMRT technique and the second group were those who received 3D-CRT. Results showed that sever acute skin toxicity or moist desquamation in IMRT group was 6% vs. 18% in 3DCRT group (p<0.05). And, the sever TRL with IMRT technique was 9% compared 21% among those of the 3D-CRT group (p<0.05). The IMRT technique resulted in statistically significant lower incidence of sever acute skin toxicities as well as less sever TRL when compared with 3D-CRT technique.
{"title":"The Intensity Modulated Radiotherapy vs . the 3D-Conformal Radiotherapy Regarding Acute Radiation Skin Toxicity and TreatmentRelated Lymphopenia in Early-Stage Breast Cancer Patients","authors":"Osama H Elzaafarany, E. Ali, S. Fadel, A. Kandil","doi":"10.4172/2155-9619.1000401","DOIUrl":"https://doi.org/10.4172/2155-9619.1000401","url":null,"abstract":"Adjuvant radiotherapy is an integral part of breast cancer treatment, and there was a great evolution of radiotherapy techniques over the past few years. Intensity-modulated radiation therapy (IMRT) was developed in the 1990s as a modern technique aiming to spare normal tissues from toxic effects of radiotherapy. This study aimed at comparing the IMRT technique to the 3D-coformal radiotherapy technique (3D-CRT) in early breast cancer patients regarding the occurrence of acute skin toxicities and treatment-related lymphopenia (TRL). It is a prospective study conducted on 100 eligible patients who were divided equally between two groups; the first, are patients received adjuvant radiotherapy using IMRT technique and the second group were those who received 3D-CRT. Results showed that sever acute skin toxicity or moist desquamation in IMRT group was 6% vs. 18% in 3DCRT group (p<0.05). And, the sever TRL with IMRT technique was 9% compared 21% among those of the 3D-CRT group (p<0.05). The IMRT technique resulted in statistically significant lower incidence of sever acute skin toxicities as well as less sever TRL when compared with 3D-CRT technique.","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127478515","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}
Pub Date : 2019-03-26DOI: 10.4172/2155-9619.1000398
N. Vinin, Joneetha Jones, M. Geetha, N. Yahiya, Shoaib Nawaz Pn, A. Narendran, Greeshma Ke, D. NidhinRa, R. Bharathan
Aim: The aim of this study was to evaluate the efficacy and outcome of early stage non-small cell lung carcinoma in elderly patients treated with SABR in a tertiary care cancer centre in rural India. Materials and methods: This was a retrospective study. All cases of histopathologically proven, stage 1 lung cancer patients in whom surgical management was not feasible due to various reasons were included. It included patients treated from 2013 to 2018 at our centre. Case records and radiation treatment plans were reviewed and data was collected. All were T1/T2N0 cases. Dose schedules employed were 48 Gy in 4 fractions, 60 Gy in 5 fractions and 60 Gy in 3 fractions. The primary end point was the tolerance and toxicity profile. Results: A total of 5 patients were treated at our center from 2013 to 2017. All were males. Mean age was 72 years. One had squamous cell and four had adenocarcinoma histology. The dose fractionation schedules employed where 48 Gy in 4 fractions, 60 Gy in 5 fractions and 60 Gy in 3 fractions. All tolerated treatment well. No grade 3 or 4 toxicities were observed. Conclusion: SABR is a feasible alternative curative treatment modality in stage 1 NSCLC. It is feasible and was tolerated well even in the elderly age group. This can be offered to medically inoperable patients as a curative treatment and is possible in a resource constrained setting also. This modality is a promise to future for operable stage 1 NSCLC also. But more randomized studies need to be carried out before applying it to operable lung cancer patients.
{"title":"Stereotactic Ablative Body Radiotherapy in Non-small Cell Carcinoma Lung in Elderly: Initial Experience from a Rural Tertiary Cancer Centre","authors":"N. Vinin, Joneetha Jones, M. Geetha, N. Yahiya, Shoaib Nawaz Pn, A. Narendran, Greeshma Ke, D. NidhinRa, R. Bharathan","doi":"10.4172/2155-9619.1000398","DOIUrl":"https://doi.org/10.4172/2155-9619.1000398","url":null,"abstract":"Aim: The aim of this study was to evaluate the efficacy and outcome of early stage non-small cell lung carcinoma in elderly patients treated with SABR in a tertiary care cancer centre in rural India. \u0000 \u0000Materials and methods: This was a retrospective study. All cases of histopathologically proven, stage 1 lung cancer patients in whom surgical management was not feasible due to various reasons were included. It included patients treated from 2013 to 2018 at our centre. Case records and radiation treatment plans were reviewed and data was collected. All were T1/T2N0 cases. Dose schedules employed were 48 Gy in 4 fractions, 60 Gy in 5 fractions and 60 Gy in 3 fractions. The primary end point was the tolerance and toxicity profile. \u0000 \u0000Results: A total of 5 patients were treated at our center from 2013 to 2017. All were males. Mean age was 72 years. One had squamous cell and four had adenocarcinoma histology. The dose fractionation schedules employed where 48 Gy in 4 fractions, 60 Gy in 5 fractions and 60 Gy in 3 fractions. All tolerated treatment well. No grade 3 or 4 toxicities were observed. \u0000 \u0000Conclusion: SABR is a feasible alternative curative treatment modality in stage 1 NSCLC. It is feasible and was tolerated well even in the elderly age group. This can be offered to medically inoperable patients as a curative treatment and is possible in a resource constrained setting also. This modality is a promise to future for operable stage 1 NSCLC also. But more randomized studies need to be carried out before applying it to operable lung cancer patients.","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123009411","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}
Pub Date : 2018-03-16DOI: 10.4172/2155-9619.1000359
Ayman G Mohamed, Ismail E. Mohamed, H. M. Zidan
Purpose: The present study is to investigate the measured and calculated doses for different malignant tumours utilizing various gamma criteria and QA for confirmation of IMRT/VMAT with portal dosimetry and 2D array. Methods: Different malignant tumors are treated by IMRT/VMAT techniques on Varian IX linear accelerator with 6 MV photon beams. Treatment planning system (TPS) is used to plan Patient’s charts. Gamma Index (GI) variation is compared to the procedure of pre-treatment verification in IMRT/VMAT plans. Results: The gamma criteria (DD/ DTA) of IMRT for (3%/3 mm), mean ± SD are γ≤ 1%=99.41% ± 0.67%, γmax=2.11 ± 0.56 and γavg=0.23 ± 0.03 by EPID, and γ% ≤ 1=98.55% ± 0.79%, γmax=1.65 ± 0.45 and γavg=0.27 ± 0.04 by using 2D array. For VMAT mean ± SD are γ% ≤ 1= 99.42% ± 0.67%, γmax=2.11 ± 0.56 and γavg= 0.19 ± 0.05 using portal dosimetry, and γ% ≤ 1=99.36% ± 0.53%, γmax=1.65 ± 0.45 and γavg=0.22 ± 0.05 using 2D array. Conclusions: Specific QA of IMRT/VMAT patient using (portal dosimetry or 2D array) to verify IMRT/VMAT fields. 3%/3 mm is the most appropriate of gamma criteria (DD/DTA) for IMRT/VMAT plans quality assurance. The control chart is an effective tool to detect uncontrolled variation.
{"title":"Portal Dosimetry for Pre-treatment Verification of Imrt/Vmat Plan: A Comparison with 2D Array Detector for Quality Assurance","authors":"Ayman G Mohamed, Ismail E. Mohamed, H. M. Zidan","doi":"10.4172/2155-9619.1000359","DOIUrl":"https://doi.org/10.4172/2155-9619.1000359","url":null,"abstract":"Purpose: The present study is to investigate the measured and calculated doses for different malignant tumours utilizing various gamma criteria and QA for confirmation of IMRT/VMAT with portal dosimetry and 2D array. \u0000Methods: Different malignant tumors are treated by IMRT/VMAT techniques on Varian IX linear accelerator with 6 MV photon beams. Treatment planning system (TPS) is used to plan Patient’s charts. Gamma Index (GI) variation is compared to the procedure of pre-treatment verification in IMRT/VMAT plans. \u0000Results: The gamma criteria (DD/ DTA) of IMRT for (3%/3 mm), mean ± SD are γ≤ 1%=99.41% ± 0.67%, γmax=2.11 ± 0.56 and γavg=0.23 ± 0.03 by EPID, and γ% ≤ 1=98.55% ± 0.79%, γmax=1.65 ± 0.45 and γavg=0.27 ± 0.04 by using 2D array. For VMAT mean ± SD are γ% ≤ 1= 99.42% ± 0.67%, γmax=2.11 ± 0.56 and γavg= 0.19 ± 0.05 using portal dosimetry, and γ% ≤ 1=99.36% ± 0.53%, γmax=1.65 ± 0.45 and γavg=0.22 ± 0.05 using 2D array. \u0000Conclusions: Specific QA of IMRT/VMAT patient using (portal dosimetry or 2D array) to verify IMRT/VMAT fields. 3%/3 mm is the most appropriate of gamma criteria (DD/DTA) for IMRT/VMAT plans quality assurance. The control chart is an effective tool to detect uncontrolled variation.","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130769115","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}
Pub Date : 2018-03-16DOI: 10.4172/2155-9619.S9-003
C. P. Bhatt, I. Ahmad, M. Semwal, K. Chufal
Volumetric Modulated Arc Therapy (VMAT) is a recently developed technology which, similar to Intensity Modulated Radiotherapy (IMRT), utilizes optimization algorithms to find an acceptable solution. VMAT optimization algorithms are more complex and resource intensive than IMRT algorithms, as the former have to account for many more variables including machine-specific limitations. VMAT is distinguished from traditional fixed-beam IMRT in that radiation is delivered while the gantry rotates around the patient. It is a significant advancement over fixed gantry angle IMRT in terms of the efficiency of delivery of desired complex dose distributions (dose painting) in modern-day radiotherapy. The purpose of this review is to discuss the technological development, clinical applications and quality assurance of VMAT.
{"title":"Technological Development, Clinical Application, Quality Assurance and Dosimetric Validation of Volumetric Modulated Arc Therapy (VMAT): A Comprehensive Literature Review","authors":"C. P. Bhatt, I. Ahmad, M. Semwal, K. Chufal","doi":"10.4172/2155-9619.S9-003","DOIUrl":"https://doi.org/10.4172/2155-9619.S9-003","url":null,"abstract":"Volumetric Modulated Arc Therapy (VMAT) is a recently developed technology which, similar to Intensity Modulated Radiotherapy (IMRT), utilizes optimization algorithms to find an acceptable solution. VMAT optimization algorithms are more complex and resource intensive than IMRT algorithms, as the former have to account for many more variables including machine-specific limitations. VMAT is distinguished from traditional fixed-beam IMRT in that radiation is delivered while the gantry rotates around the patient. It is a significant advancement over fixed gantry angle IMRT in terms of the efficiency of delivery of desired complex dose distributions (dose painting) in modern-day radiotherapy. The purpose of this review is to discuss the technological development, clinical applications and quality assurance of VMAT.","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124413692","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}
Pub Date : 2018-03-08DOI: 10.4172/2155-9619.1000357
A. Maghous, E. Marnouche, N. Zaghba, K. Andaloussi, M. Elmarjany, K. Hadadi, H. Sifat, R. Moussaoui, H. Mansouri
Breast cancer is the most frequently diagnosed cancer type among women worldwide. The treatment of breast cancer is multimodal and the current standard approach is surgery followed by adjuvant radiotherapy (RT) based on prognostic scores. Neoadjuvant chemotherapy and RT delivered in advance of surgery are used in some early stage and locally advanced cases, may offer an advantage over adjuvant therapy related to the potential benefits in the pathologic response and survival outcomes based the hypothesis of Abscopal effect.
{"title":"Neoadjuvant Radiotherapy of Early-Stage and Locally Advanced Breast Cancer: Review of the Literature","authors":"A. Maghous, E. Marnouche, N. Zaghba, K. Andaloussi, M. Elmarjany, K. Hadadi, H. Sifat, R. Moussaoui, H. Mansouri","doi":"10.4172/2155-9619.1000357","DOIUrl":"https://doi.org/10.4172/2155-9619.1000357","url":null,"abstract":"Breast cancer is the most frequently diagnosed cancer type among women worldwide. The treatment of breast cancer is multimodal and the current standard approach is surgery followed by adjuvant radiotherapy (RT) based on prognostic scores. Neoadjuvant chemotherapy and RT delivered in advance of surgery are used in some early stage and locally advanced cases, may offer an advantage over adjuvant therapy related to the potential benefits in the pathologic response and survival outcomes based the hypothesis of Abscopal effect.","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116046491","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}
Pub Date : 2018-03-08DOI: 10.4172/2155-9619.1000358
E. Kucuktulu, A. F. Yurekli, Eray Bilcan, Mahmut Serdar Sisecioglu, M. Topbaş, U. Kucuktulu
Introduction: The doses received by the contralateral breast, lung and heart either directionally or full blocked techniques in Hi-Art Tomotherapy systems in partial or whole breast radiotherapy has been studied. Method: In 20 breast cancer patients 3 plans with non-blocked, directionally blocked and full blocked methods were designed in Hi-Art planning system. In all planning method the dose received by the contralateral breast, the heart volume percentages V5 and V30 and the lung volume percentages V5 and V20 were compared. Results: The mean doses received by contralateral breast were 6.24 Gy (4.50-8.74 Gy) in unblocked group 3.85 Gy (2.08-5.81 Gy) in directionally blocked group and 0.99 Gy (0.69-1.39 Gy) in full blocked group. The mean Lung V5 values were 98% (79-100%) in unblocked group and it was 98% (91-100%) in directionally blocked group while it was 93% (89-97%) in full blocked group. The mean V20 values were 16% (7-23%), 20% (17-24%) and 22% (18-28%) in unblocked, directionally blocked and full blocked groups respectively. The mean Heart V5 value 100% (99-100%) in unblocked group, and it was 99% (85-100%) in directionally blocked group while it was 92% (73- 100%) in full blocked group. The mean V30 values were 11% (2-25%), 6% (0-12%) and 9% (1-22%) in unblocked, directionally blocked and full blocked groups respectively. The mean beam-on time was 261.6 s (237.6-318.2) for unblocked, 277.9 s (237.6-338.5) for directionally blocked and 314.2 s (272.6-429.1) full blocked group. The mean numbers of MUs were 3712 (3353-4536) for unblocked, 3951 (3357-4834) for directionally blocked and 4506 (3866- 6168) for full blocked group. In full blocked group both beam on time and MU values were higher. Conclusion: We propose that further efforts needed to reduce low dose volumes to normal tissues, meanwhile when using directionally and full blocked plans all parameters should be considered together.
{"title":"Comparison of Unblocked, Directionally Blocked and Full Blocked Plans in Helical Tomotherapy for Breast Cancer Radiotherapy","authors":"E. Kucuktulu, A. F. Yurekli, Eray Bilcan, Mahmut Serdar Sisecioglu, M. Topbaş, U. Kucuktulu","doi":"10.4172/2155-9619.1000358","DOIUrl":"https://doi.org/10.4172/2155-9619.1000358","url":null,"abstract":"Introduction: The doses received by the contralateral breast, lung and heart either directionally or full blocked techniques in Hi-Art Tomotherapy systems in partial or whole breast radiotherapy has been studied. \u0000Method: In 20 breast cancer patients 3 plans with non-blocked, directionally blocked and full blocked methods were designed in Hi-Art planning system. In all planning method the dose received by the contralateral breast, the heart volume percentages V5 and V30 and the lung volume percentages V5 and V20 were compared. \u0000Results: The mean doses received by contralateral breast were 6.24 Gy (4.50-8.74 Gy) in unblocked group 3.85 Gy (2.08-5.81 Gy) in directionally blocked group and 0.99 Gy (0.69-1.39 Gy) in full blocked group. The mean Lung V5 values were 98% (79-100%) in unblocked group and it was 98% (91-100%) in directionally blocked group while it was 93% (89-97%) in full blocked group. The mean V20 values were 16% (7-23%), 20% (17-24%) and 22% (18-28%) in unblocked, directionally blocked and full blocked groups respectively. The mean Heart V5 value 100% (99-100%) in unblocked group, and it was 99% (85-100%) in directionally blocked group while it was 92% (73- 100%) in full blocked group. The mean V30 values were 11% (2-25%), 6% (0-12%) and 9% (1-22%) in unblocked, directionally blocked and full blocked groups respectively. The mean beam-on time was 261.6 s (237.6-318.2) for unblocked, 277.9 s (237.6-338.5) for directionally blocked and 314.2 s (272.6-429.1) full blocked group. The mean numbers of MUs were 3712 (3353-4536) for unblocked, 3951 (3357-4834) for directionally blocked and 4506 (3866- 6168) for full blocked group. In full blocked group both beam on time and MU values were higher. \u0000Conclusion: We propose that further efforts needed to reduce low dose volumes to normal tissues, meanwhile when using directionally and full blocked plans all parameters should be considered together.","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114610852","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}
Pub Date : 2018-02-20DOI: 10.4172/2155-9619.1000354
V. Mhatre, S. Pilakkal, P. Chadha, Kaustav Talpatra
Aim: This study investigates the dosimetric impact of a-Si 1200 over a-Si 1000 portal imager for 6 MV photon beam of a Varian Amorphous Silicon Electronic Portal Imaging Device (a-Si EPID) installed on Edge and Novalis TxLinac. Materials and Methods: The performance of an a-Si EPID 1200 was assessed and compared to its performance with a-Si EPID 1000 and dose measurements using an ionization chamber. This study was conducted for 6MV photon energy and the EPID performance was assessed as function of the delivered dose, dose rate, field size, SDD effect, Ghosting effect, Backscatter arm shielding impact and intensity-modulated radiation therapy fields. Results: The dose response for a-Si 1200 was within 0.5% for low MU (2-10) as compared to 1.4% for a-Si 1000 portal imager and less than 1% for both the imager above 10 MU. The output factor variation for 25 × 25 cm2 was 1.3% for a-Si 1200 and 3.8% for a-Si 1000 when compared with ionisation chamber. The ghosting was measured to be 0.2% for a-Si 1200 as compared to 0.8% for a-Si 1000 portal imager. There is a significant improvement in a-Si 1200 portal image due to backscatter shielding material attached to the back of the panel of a-Si 1200 portal imager. Conclusion: The new aS1200 detector showed a significant dosimetric improvement when compared with previous aS1000 hence providing more accurate measurements for pre-treatment patient specific Quality Assurance (QA).
目的:研究安装在Edge和Novalis TxLinac上的瓦里安非晶硅电子传送门成像装置(a- si EPID)的6 MV光子束中，a- si 1200对a- si 1000传送门成像仪的剂量学影响。材料和方法:评估了a-Si epid1200的性能，并将其与a-Si epid1000的性能和使用电离室的剂量测量进行了比较。本研究以6MV光子能量为研究对象，通过传递剂量、剂量率、场大小、SDD效应、重影效应、后向散射臂屏蔽冲击和调强放疗场的函数来评估EPID的性能。结果:低MU(2-10)时，a-Si 1200的剂量反应在0.5%以内，而a-Si 1000门静脉成像仪的剂量反应为1.4%，10 MU以上的剂量反应均小于1%。与电离室相比，25 × 25 cm2的a-Si 1200输出因子变化为1.3%，a-Si 1000输出因子变化为3.8%。经测量，a-Si 1200的重影率为0.2%，而a-Si 1000的重影率为0.8%。由于在a- si 1200传送门成像仪面板背面附加了后向散射屏蔽材料，使得a- si 1200传送门成像有了明显的改善。结论:与以前的aS1000相比，新的aS1200检测仪显示出显著的剂量学改进，因此为治疗前患者特异性质量保证(QA)提供了更准确的测量。
{"title":"Dosimetric Comparison of a-Si 1200 and a-Si 1000 Electronic Portal Imager for Intensity Modulated Radiation Therapy (IMRT)","authors":"V. Mhatre, S. Pilakkal, P. Chadha, Kaustav Talpatra","doi":"10.4172/2155-9619.1000354","DOIUrl":"https://doi.org/10.4172/2155-9619.1000354","url":null,"abstract":"Aim: This study investigates the dosimetric impact of a-Si 1200 over a-Si 1000 portal imager for 6 MV photon beam of a Varian Amorphous Silicon Electronic Portal Imaging Device (a-Si EPID) installed on Edge and Novalis TxLinac. Materials and Methods: The performance of an a-Si EPID 1200 was assessed and compared to its performance with a-Si EPID 1000 and dose measurements using an ionization chamber. This study was conducted for 6MV photon energy and the EPID performance was assessed as function of the delivered dose, dose rate, field size, SDD effect, Ghosting effect, Backscatter arm shielding impact and intensity-modulated radiation therapy fields. Results: The dose response for a-Si 1200 was within 0.5% for low MU (2-10) as compared to 1.4% for a-Si 1000 portal imager and less than 1% for both the imager above 10 MU. The output factor variation for 25 × 25 cm2 was 1.3% for a-Si 1200 and 3.8% for a-Si 1000 when compared with ionisation chamber. The ghosting was measured to be 0.2% for a-Si 1200 as compared to 0.8% for a-Si 1000 portal imager. There is a significant improvement in a-Si 1200 portal image due to backscatter shielding material attached to the back of the panel of a-Si 1200 portal imager. Conclusion: The new aS1200 detector showed a significant dosimetric improvement when compared with previous aS1000 hence providing more accurate measurements for pre-treatment patient specific Quality Assurance (QA).","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130676749","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}
Pub Date : 2017-12-24DOI: 10.4172/2155-9619.1000351
Gozde Arslan, E. Inci
Objective: We aimed to determine the usefulness of the apparent diffusion coefficient (ADC) values for the differential diagnosis of hepatocellular carcinomas and most common metastatic liver tumors and we aimed to compare the characteristic properties. We also aimed to detect novel lesions on ADC maps before the lesion is clinically and radiologically detected by conventional methods. Materials and Methods: We evaluated characteristic properties, contrast enhancement patterns of liver metastasis of malignancies like adenocancer, renal cell carcinoma (RCC), gastrointestinal stromal tumor (GIST) and hepatocellular carcinoma (HCC) on magnetic resonance imaging (MRI) and diffusion weighted (DW) imaging. ADCs were measured both from the cystic and solid parts of the tumoral lesions. Solid and cystic parts were grouped seperately and compared individually. Results: 48 cases, (60% male and 40% female) with ages ranging between 48 and 81 were involved. 28 of them had liver metastasis and 20 of them had HCC. MRIs between the years 2009 and 2012 were analyzed. Among mean ADC values measured from solid contrast-enhancing parts, values of the HCC group were significantly higher than the metastasis group (p=0.004). Also, in metastasis group consisting of many distinct primaries, there were differences in ADC values. A retrospective analysis for follow-up cases showed that the ADC values of the parencyhma where a lesion will appear on later follow-up images were lower than the adjacent parenchyma. Conclusion: We believe that this method may be useful to detect early metastasis. Studies with larger patient groups could give more significant results which would enable diffusion imaging method to be used in this area.
{"title":"Evaluation of Hepatocellular Carcinomas and Liver Metastases- How Far can we Go with Diffusion Weighted Imaging?","authors":"Gozde Arslan, E. Inci","doi":"10.4172/2155-9619.1000351","DOIUrl":"https://doi.org/10.4172/2155-9619.1000351","url":null,"abstract":"Objective: We aimed to determine the usefulness of the apparent diffusion coefficient (ADC) values for the differential diagnosis of hepatocellular carcinomas and most common metastatic liver tumors and we aimed to compare the characteristic properties. We also aimed to detect novel lesions on ADC maps before the lesion is clinically and radiologically detected by conventional methods. \u0000Materials and Methods: We evaluated characteristic properties, contrast enhancement patterns of liver metastasis of malignancies like adenocancer, renal cell carcinoma (RCC), gastrointestinal stromal tumor (GIST) and hepatocellular carcinoma (HCC) on magnetic resonance imaging (MRI) and diffusion weighted (DW) imaging. ADCs were measured both from the cystic and solid parts of the tumoral lesions. Solid and cystic parts were grouped seperately and compared individually. \u0000Results: 48 cases, (60% male and 40% female) with ages ranging between 48 and 81 were involved. 28 of them had liver metastasis and 20 of them had HCC. MRIs between the years 2009 and 2012 were analyzed. Among mean ADC values measured from solid contrast-enhancing parts, values of the HCC group were significantly higher than the metastasis group (p=0.004). Also, in metastasis group consisting of many distinct primaries, there were differences in ADC values. A retrospective analysis for follow-up cases showed that the ADC values of the parencyhma where a lesion will appear on later follow-up images were lower than the adjacent parenchyma. \u0000Conclusion: We believe that this method may be useful to detect early metastasis. Studies with larger patient groups could give more significant results which would enable diffusion imaging method to be used in this area.","PeriodicalId":302578,"journal":{"name":"Journal of Nuclear Medicine and Radiation Therapy","volume":"221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116410569","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}
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