Indian Journal of Nuclear Medicine最新文献

Small-cell carcinoma of the prostate (SCCP) is a rare and very aggressive malignancy with neuroendocrine differentiation. In contrast to conventional prostate adenocarcinoma, SCCP is an aggressive carcinoma and portends to have a poor prognosis. Around 50% of these patients have metastatic disease at the first clinical presentation. We report the findings of 18-F fluorodeoxyglucose positron emission tomography/computed tomography in a case of histologically proven SCCP with an unusual finding of the left internal mammary lymph node.

Purpose: We proposed to administer Lu-177-DOTATATE in intra-arterial (IA) mode for higher first-pass localization to somatostatin receptors, higher residence time in liver metastases, and more radiation to tumor. This study aimed at assessing early hematological, renal and hepatotoxicity; and objective response to IA peptide receptor radionuclide therapy (PRRT).

Materials and methods: Fourteen patients (4 females and 10 males) were prospectively assessed. 5/14 patients underwent 2 cycles, whereas 3/14 underwent 3 cycles, and 6/14 received 1 cycle of IA PRRT. 200 mCi of Lu-177-DOTATATE was administered in 15-20 min by IA route under angiographic guidance. Patients were asked to follow-up at 4 and 8 weeks with hematological, liver, and renal functional parameters, and Ga-68 DOTATATE positron emission tomography/computed tomography (PET/CT) after 8 weeks. Response was assessed using RECIST 1.1 and EORTC PET criteria.

Results: Safety: 2/14 patients had high total and direct bilirubin, which reverted to normal after IA PRRT. Three patients had low albumin, which improved after 1 cycle. Nine patients showed no worsening of liver function. Two patients showed Grade 1 hematotoxicity which reverted to normal. Five patients showed high creatinine, but preserved glomerular filtration rate and EC clearance. On follow-up at 8 weeks, serum creatinine reverted to normal. Efficacy: In five patients who underwent 2 cycles of IA PRRT, 3 showed partial response (PR) on RECIST 1.1 and partial metabolic response (PMR) on EORTC criteria, whereas 2 showed stable disease (SD). In patients who underwent 3 cycles, 1 showed SD, whereas other patient showed PMR on DOTANOC PET/CT, with PR in size. Among the remaining seven patients, 5 showed PMR, whereas the other 2 showed SD. Thus 9/14 patients showed PR, whereas 5 showed SD on metabolic and size criteria.

Conclusions: IA PRRT is a safe and efficacious approach for the treatment of liver dominant metastatic neuroendocrine tumors.

Metallosis is a medical condition that shows local and systemic clinical symptoms due to the deposition of heavy metal debris in soft tissues and bones due to metallic prostheses. The estimated incidence of Metallosis is around 5%. Clinical presentation and imaging findings can mimic tumor likely situation, However local reactions of Metallosis shows some peculiar features on cross-sectional imaging, and here we present two such cases of Metallosis with its imaging findings.

Background: Radioactive solid and liquid waste generated by patients after high-dose iodine therapy may lead to significant radiation exposure if not properly handled.

Aims and objectives: This study was conducted to monitor the radiation exposure along the sewerage drainage system of the high-dose iodine therapy ward and to rule out leakage if any, that might pose a potential radiation hazard to the general public (sewerage workers) and radiation health professional.

Materials and methods: The sewerage drainage system from isolation wards has multiple gate valves to regulate sewerage flow from the high-dose iodine therapy ward into delay and decay tanks (DDT) built, especially for the purpose. Radiation surveillance was done using a Geiger-Muller counter-based survey meter at 11 different locations on a weekly basis for 12 weeks.

Results: A total of 26 patients underwent high-dose iodine ablation therapy during the study period in our department, with the highest recorded radiation exposure rate in the sewerage draining system in the 9^th week of patient admission. This was at the common gate valve junction (location B) that directed sewerage waste from all four isolation rooms into the common pipeline leading to DDT. Minimal radiation exposure was recorded within Atomic Energy Regulatory Board -prescribed limits with no evidence of leakage.

Conclusion: A routine radiation survey is an important component of overall radiation safety in the nuclear medicine department, including sewerage delay tank facilities, which helps keep the radiation exposure to acceptable levels by identifying timely leakage.

Background: Positron emission tomography with computed tomography (PET-CT) using fluorine 18-fluorodeoxyglucose (F-18 FDG) is increasingly used to stage patients with locally advanced breast cancer and for assessing treatment response after neoadjuvant chemotherapy (NACT).

Aims and objectives: The aim of the study was to assess the correlation between PET-CT parameters and pathologic response of breast primary after NACT in breast cancer patients and to devise a grading system called NIMS grading system for response assessment using PET quantitative parameters.

Materials and methods: 55 patients who underwent F-18 FDG PET-CT before starting the therapy and again after completion of therapy were identified and included in the study. The clinical data and the histopathologic findings were recorded. All the patients received chemotherapy followed by surgery with axillary lymph node dissection. The PET-CT results were interpreted both qualitatively by visual analysis and quantitatively by estimating maximum Standardized uptake values(SUV_max) and other parameters - SUVmean, SUL, SUV_BSA, Metabolic tumor volume (MTV) and Total lesion glycolysis (TLG).

Results: The sensitivity and specificity of F-18 FDG PET-CT to detect the residual disease after neoadjuvant chemotherapy was 75.6% & 92.8% respectively. Differences between complete response and residual disease were significant for ΔSUV_max(p=0.005), ΔSUV_mean(p=0.006), ΔSUL (0.005) and ΔSUV_BSA(0.004), while ΔMTV and ΔTLG were not significantly different between the two groups. The new NIMS grading system included scoring of ΔSUV_max, ΔSUV_BSA, ΔTLG and ΔMTV on scale of 1 to 4 and correlated well with PERCIST criteria.

Conclusion: F-18 FDG PET-CT had a good accuracy in the detection of residual disease after completion of NACT. Pre chemotherapy PET-CT is not adequate to predict the response of primary tumour to chemotherapy. However, changes in the values of various PET-CT parameters are a sensitive tool to assess the response to chemotherapy. The new grading system is easy to use and showed good correlation to PERCIST.

Follicular thyroid cancer is the second-most common type of thyroid cancer after papillary thyroid cancer. Metastases to the mandible and maxillofacial region are rare. Our study presents a 55-year-old patient who underwent total thyroidectomy for follicular thyroid cancer and subsequent radioactive iodine therapy. Sixteen years after diagnosis, elevated thyroglobulin levels suggested disease recurrence. Using advanced imaging techniques - Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan, bone scintigraphy, and posttreatment I-131 scan-an unexpected metastatic site was identified: the left mandibular condyle. A biopsy confirmed the presence of metastatic follicular thyroid cancer.

Aim and background: The aim of this study was to evaluate the prognostic value of imaging-based variables and tumor marker in predicting the progression-free survival (PFS) in treatment-naïve pancreatic cancer (PC) using baseline 18-fluorodeoxyglucose (¹⁸FDG) positron emission tomography/computed tomography (PET/CT).

Materials and methods: This retro-prospective study was conducted at PET/CT imaging facility of JCIA health-care facility of Pakistan. Total 68 patients with PCs were retrospectively included who had ¹⁸FDG PET/CT for staging from March 2017 to December 2020. Thirty-two patients had unresectable Stage IV disease on baseline imaging while the remaining 36 underwent Whipple's procedure and both categories were followed by chemotherapy with/without immunotherapy. These patients were followed for a median period of 18 months (1-62 months) for PFS. Logistic regression analysis and receiver operating characteristic (ROC) analysis were used for independent predictors of patients' demographics, tumor characteristics, CA 19-9, and maximum standardized uptake value (SUVmax) in PFS. Kaplan-Meier's survival curves were analyzed to measure PFS using ROC-derived significant cutoff values of CA 19-9 and SUVmax.

Results: Median PFS was 18 months (11-45) with 60% (41/68) patients were either died or labelled having metabolic progressive disease (MPD. Using logistic regression analysis, significant correlations were found for Stage IV disease and pancreatic body/tail tumor with disease progression (odd ratio: 7.535 and 4.803, respectively; P < 0.05). Gender, obesity, histological tumor type, and ¹⁸FDG-avid regional nodes did not show a significant impact on PFS. On ROC analysis, SUVmax >5.3 of primary tumor and baseline CA 19-9 >197 U/ml were found to have a significant negative correlation with PFS (area under the curve: 0.827 and 0.911, respectively; P < 0.0001) and no association of age and primary tumor size in PFS. Significantly, shorter PFS was found using ROC-derived cutoff values of SUVmax >5.3 versus ≤5.3 of primary tumor (mean and 95% confidence interval [CI]: 16.7 vs. 48.5 and 10-23 vs. 41-56; log-rank = 25.014; P < 0.0001) and baseline CA 19-9 >197 versus ≤197 U/ml (mean and 95% CI: 11.8 vs. 46.9 and 7-16 vs. 39-55; log-rank = 38.217; P < 0.0001).

Conclusion: SUVmax >5.3 of primary tumor and baseline CA 19-9 >197 U/ml were found to have a significant negative correlation with PFS in treatment-naïve PC patients. Among demographics, only Stage IV disease and pancreatic tail and body tumors were found to have a negative association with disease progression.

A 38-year-old woman with papillary carcinoma of the thyroid who underwent total thyroidectomy followed by high-dose radioiodine ablation was called for Iodine-131 (I-131) whole-body follow-up scan. Her follow-up scan revealed focal tracer accumulation in the lower aspect of the right posterior neck region. Her stimulated serum thyroglobulin and anti-thyroglobulin antibodies were 0.27 ng/ml and undetectable, respectively. Further clinical examination of the patient revealed a black scab in the same region. The patient revealed a history of wasp bite 2 days before iodine administration.

Diffuse Tc-99m MIBI uptake in the lungs during parathyroid scintigraphy is exceptional, and only a few cases have described this unusual aspect. The differential diagnostic of this funding is a challenge when interpreting the examination, since it can be a sign of serious pathology. We report the case of unexpected diffusely increased Tc-99m MIBI uptake in bilateral lung fields in a patient with left cardiac dysfunction.