Search

Purpose: The clinico-radiological dilemma in post-treatment high-grade gliomas, between disease recurrence (TR) and treatment-related changes (TRC), still persists. FET (Fluoro-ethyl-tyrosine) PET has been extensively used as problem-solving modality for cases where MR imaging is inconclusive. We incorporated a systematic imaging and clinical follow-up algorithm in a multi-disciplinary clinic (MDC) setting to analyse our cohort of FET PET in post-treatment gliomas., Methods: We retrospectively analyzed 171 patients of post-treatment grade III and IV glioma with equivocal findings on MRI. 185-222 MBq of 18 F-FET was injected and dedicated static imaging of brain was performed at 20 min. TBR (Tumor to background ratio) was used as semi-quantitative parameter. Cutoff of 2.5 was used for image interpretation. Imaging findings were confirmed with histopathological diagnosis, wherever available or in a multidisciplinary joint clinic based on serial imaging., Results: 121 of 171 patients showed recurrent disease on FET PET, on follow up, 109 were confirmed with recurrence; 7 patients showed TRC, whereas 5 were treated with bevacizumab, with no further clinico-radiological deterioration, thus confirming TRC. 50 patients showed TRC on FET PET, on follow up on follow up, 40 were confirmed as true-negative. 10 patients who showed TBR less than 2.5 had confirmed TR on subsequent MR imaging. The overall sensitivity and specificity was 91.6 and 76.9% respectively, with a diagnostic accuracy of 87.13%., Conclusion: There is potential for FET PET to be used along with MRI in the post treatment algorithm of high-grade glial tumors., Competing Interests: Declarations Ethical approval The study was approved by Institutional Ethics Committee, Tata Memorial Hospital (Project No – 900717). Informed consent Since this is a retrospective study, waiver of consent was given by Institutional Ethics Committee. However, as part of standard practice, written and informed consent was taken before undergoing FET PET and MRI procedure. Conflict of interest There are no conflicts of interest. No competing interests or disclosures., (© 2024. The Author(s).)

Programmed Death 1 (PD1) and Programmed Death Ligand (PDL1) play a crucial role in tumor microenvironment by helping cancer cells evade innate immunity. Numerous inhibitor anticancer drugs targeting this interplay have been used in clinical practice and many more are in preclinical stage. These drugs have shown promising results in achieving good response and long-term clinical benefit, is routinely performed to identify patients who may benefit. However, there are major challenges associated with these immunohistochemistry tests which have opened the space for noninvasive imaging modalities using PD1 and PDL1 inhibitors labeled with either PET or SPECT radionuclides. These radiopharmaceuticals, although primarily developed for the field of immunotherapy, have great potential in expanding and optimizing the combination of radiopharmaceutical therapies with PD1-PDL1 targeting anticancer drugs. This review elaborates currently available PET and SPECT radiopharmaceuticals targeting PD1-PDL1 axis. It also explores the potential future role of newer targets which are being developed and tested in various preclinical studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Diffuse midline glioma, H3 K27 -altered is a rare and aggressive pediatric brain tumor with a grim prognosis. Diffuse midline glioma is characterized by specific molecular alterations, including H3 K27 mutations, and involves deep midline structures such as the brainstem, cerebellum, spinal cord, and thalamus. These tumors present with a classic triad of symptoms and have limited surgical options due to their challenging locations. Extra-neural metastases are an unusual occurrence in diffuse midline glioma and have been rarely described. Here we report a 17-year-old girl with spinal diffuse midline glioma, H3 K27M-mutant, who presented with multiple metastatic osseous lesions confirmed on biopsy of the thoracic vertebral lesion. Due to the rapid disease progression, the patient was recommended palliative therapy. Extra-neural metastases in diffuse midline glioma are rare, with only 16 reported patients, and no standard therapy exists. An accurate and early diagnosis is necessary to develop a personalized plan of treatment. Further research is needed to gain insights into the molecular pathology of diffuse midline glioma, H3 K27 -altered, and improve the quality of life and the outcome of patients with this deadly disease., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The authors also declare that there was no funding involved for this work.

Objective: 177 Lu-DOTATATE peptide receptor therapy (PRRT) is an established treatment for patients suffering from neuroendocrine tumors. In the last few years, intra-arterial PRRT is being considered for patients having liver metastatic disease predominantly. The aim of our study is to measure the radiation doses received by the treating intervention radiologists involved in intra-arterial PRRT treatment using 177 Lu-DOTATATE., Materials and Methods: Radiation safety-related data of 31 patients who underwent 177Lu-DOTATATE intra-arterial PRRT treatment were used for this study. The exposure rate was measured at the hand and eye and chest level of treating intervention radiologists continuously from the beginning to the end of the administration. Exposure from the patient at the body surface (at the level of liver, thigh, and extremities) and 1 m from the body surface was measured just after the administration. The mean radiation exposure from the patient at the body surface and 1 m from the body was also calculated., Results: The mean administered activity was found to be 194 (±17) mCi. The mean radiation exposure at the surface at the level of the liver, thigh, and feet and at 1 m from the surface was found to be 100 (±25.11), 9 (±1.27), 5.6 (±0.52), and 5.3± (0.50) μSv/hr, respectively. The mean administration time was found to be 23 ± 5.6 min. The mean radiation dose to the hands, and eyes, of the treating intervention radiologist per procedure, was found to be 6.425 ± 2.75 μSv, 5.43 ± 1.76 μSv and 1-m exposure from the patient was found to be 5.3 ± 0.246 μSv, respectively., Conclusion: Our result shows that the radiation exposure from the patient postadministration is below the permissible limit of discharge. The radiation exposure to the intervention radiologist is also suggestive of a safe procedure to be performed by maintaining the radiation dose well within the permissible limit for radiation professionals., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Indian Journal of Nuclear Medicine.)

Extracranial metastasis from high-grade glial tumors is an extremely rare condition with its reported incidence being <1%. The most common sites reported in the literature are leptomeninges and spinal cord, followed by the liver, lung, and skeletal system. Its low incidence is thought to be related to the intrinsic aggressive biology of the tumor, thus reducing median overall survival in patients. As there is lack of knowledge about the mechanism of extracranial spread of glioma cells, its diagnosis and management remain a major challenge. We report two cases of extracranial metastases from glial tumors to cervical nodes and postoperative site involving preauricular region detected on F18 Fluoro ethyl tyrosine (FET) positron emission tomography-computed tomography and later on confirmed with histopathology Fluoro ethyl tyrosine., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Indian Journal of Nuclear Medicine.)

Purpose: Refractory and/or recurrent meningiomas have poor outcomes, and the treatment options are limited. Peptide receptor radionuclide therapy (PRRT) has been used in this setting with promising results. We have documented our experience of using intravenous (IV) and intra-arterial (IA) approaches of Lu-177 DOTATATE PRRT., Methods: Eight patients with relapsed/refractory high-grade meningioma received PRRT with Lu-177 DOTATATE by IV and an IA route. At least 2 cycles were administered. Time to progression was calculated from the first PRRT session to progression. The response was assessed on MRI using RANO criteria, and visual analysis of uptake was done on Ga-68 DOTANOC PET/CT. Post-therapy dosimetry calculations for estimating the absorbed dose were performed., Results: Median time to progression was 8.9 months. One patient showed disease progression, whereas seven patients showed stable disease at 4 weeks following 2 cycles of PRRT. Dosimetric analysis showed higher dose and retention time by IA approach. No significant peri-procedural or PRRT associated toxicity was seen., Conclusion: PRRT is a safe and effective therapeutic option for relapsed/refractory meningioma. The IA approach yields better dose delivery and should be routinely practised., (Copyright © 2024 Copyright: © 2024 Neurology India, Neurological Society of India.)

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., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Indian Journal of Nuclear Medicine.)

Fibroblast-activated protein (FAP) expression in glial cells is attributed to FAP-positive foci on tumor vessels and neoplastic cells. Preclinical and pilot studies have shown FAP expression in high-grade gliomas. We aimed at comparing PET imaging with FAP-inhibitor (FAPI-PET) with current standard, i.e., fluoro-ethyl tyrosine (FET) PET in post-treatment setting to differentiate recurrence and post-treatment changes. 6 patients with WHO Grade III and IV glioma who received standard treatment underwent Ga-68-FAPI-04 PET/CT (FAPI-PET/CT). Tracer uptake greater than background was considered positive. FET PET was performed and interpreted as per institutional standards, which formed the basis of treatment decision. There was concordance between FAPI expression and FET uptake in 5 patients suggestive of disease recurrence. There was no FAPI expression seen in 1 patient, in whom FET PET was suggestive of post-treatment changes. FAPI PET uptake correlated with amino acid expression to differentiate post treatment changes from recurrence in high-grade glial tumors; further validation with prospective study and histopathological confirmation is needed., Competing Interests: The authors declare that they have no conflicts of interest., (© The Author(s) 2024.)

Abstract: PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology., (Copyright © 2024 Copyright: © 2024 Indian Journal of Cancer.)

Purpose: To analyze diagnostic performance of F-18 FDG PET/CT in recurrent adenocarcinoma gallbladder (GBC) and to establish its possible impact on post-recurrence survival., Method: FDG PET/CT studies of suspected recurrent GBC were retrospectively analyzed alongside tumor markers serum CEA and CA 19-9. Abnormal FDG-avid lesions and abnormal morphological lesions were considered positive for recurrence, and were categorized as isolated abdominal wall recurrence, loco-regional recurrence, and distant metastatic disease. Histopathology, definite progression on imaging and positive response to treatment was considered as reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were used as diagnostic performance parameters. Post-recurrence survival was calculated whenever appropriate follow-up was available, based on the abovementioned categories of sites of recurrence using survival curves and log-rank test., Results: Out of 117 PET/CT studies, 93 (79.5%) were positive and 24 (20.5%) were negative for recurrence. 86 out of 93 were true positive and 23 of 24 were true negative. PET/CT demonstrated sensitivity, specificity, PPV, NPV and accuracy of 98.8%, 76.7%, 92.5%, 95.8% and 93.1%, respectively. Diagnostic performance of PET/CT was significantly better than combination tumor markers. Of 66 cases with available follow-up, isolated abdominal wall (port/scar site) recurrence and loco-regional recurrence demonstrated significantly higher post-recurrence survival as compared to distant metastasis; median survival being 39, 25 and 12 months, respectively., Conclusion: F-18 FDG PET/CT has better diagnostic performance than tumor markers combination. Isolated abdominal wall (port/scar site) recurrence and loco-regional recurrence on PET/CT demonstrated better survival than non-regional metastatic disease. These results suggest a possible role of PET/CT as a surveillance modality, as well as a guide to therapeutic decision-making in cases of recurrent GBC., (© 2022. The Author(s) under exclusive licence to Japan Radiological Society.)

Abstract: Sporadic cerebellar hemangioblastomas are rare with majority of these tumors presenting as a part of von Hippel-Lindau syndrome. We demonstrate an unusual case of a symptomatic sporadic cerebellar hemangioblastoma mimicking a meningioma on MRI and 68 Ga-DOTANOC PET imaging., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Imaging in prostate cancer has become increasingly important over time, as the incidence of prostate cancer has been on the rise and better screening techniques have emerged. The development of personalized systemic therapies highlights the unmet need for whole-body imaging. Prostate-specific membrane antigen (PSMA) PET, with its ease of performance and mechanism of localization to prostatic tumor cells, has now emerged as a preferred modality for diagnosis, staging, and treatment response assessment. In this context, PSMA PET can help in mapping the disease extent, both the skeletal and visceral spread, to plan targeted therapeutic approaches., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Recurrent glioblastoma (GBM) has dismal outcomes and limited treatment options. Mebendazole (MBZ) has activity in glioma both in-vivo and in-vitro , and is well tolerated in combination with lomustine (CCNU) and temozolomide (TMZ). In this study, we sought to determine whether the addition of MBZ to CCNU or TMZ would improve overall survival (OS) in recurrent GBM., Methods: In this phase II randomized open-label trial, adult patients with ECOG PS 0-3, with recurrent GBM who were not eligible for re-radiation, were randomized 1:1 to the CCNU-MBZ and TMZ-MBZ arms. CCNU was administered at 110 mg/m 2 every 6 weeks with MBZ 800 mg thrice daily and TMZ was administered at 200 mg/m 2 once daily on days 1-5 of a 28 days cycle with MBZ 1600 mg thrice daily. The primary endpoint was OS at 9 months. A 9-month OS of 55% or more in any arm was hypothesized to warrant further evaluation and a value below 35% was too low to warrant further investigation. OS was analyzed using intention to treat (ITT) and per-protocol (PP) analyses. Per-protocol analysis was used for safety analysis. Clinical Trials Registry-India number, CTRI/2018/01/011542., Findings: Participants were recruited from 14 th March 2019 to 18 th June 2021, 44 patients were randomised on each arm. At 17.4 months, 68 events for OS analysis had occurred, 33 in the TMZ-MBZ and 35 in the CCNU-MBZ arm. The 9-month OS was 36.6% (95% CI 22.3-51.0) and 45% (95% CI 29.6-59.2) in the TMZ-MBZ and CCNU-MBZ arms respectively, in the ITT population. ECOG PS was the only independent prognostic factor impacting OS (HR-0.48, 95% CI 0.27-0.85; P  = 0.012). Grade 3-5 adverse events were seen in 8 (18.6%; n  = 43) and 4 (9.5%; n  = 42) patients in the TMZ-MBZ and CCNU-MBZ arms respectively. There were no treatment related deaths., Interpretation: The addition of MBZ to TMZ or CCNU failed to achieve the pre-set benchmark of 55% 9-month OS. This was probably due to 28.6% of patients having poor PS of 2-3., Funding: Brain Tumor Foundation (BTF) of India, Indian Cooperative Oncology Network (ICON), and India Cancer Research Consortium (ICRC) under ICMR (Indian Council of Medical Research)., Competing Interests: VP reports research grants from Brain Tumor Foundation (BTF) of India, grants from Indian Cooperative Oncology Network (ICON), grants from India Cancer Research Consortium (ICRC) under ICMR (Indian Council of Medical Research), during the conduct of the study; and research grants from Janssen & Janssen, Astra Zeneca, Intas Pharmaceuticals, Natco Pharma, Cadila Healthcare, Eisai, and Novartis outside the submitted work. NM reports a research grant from Astra Zeneca outside the submitted work. All grants were paid to the institution. All other authors report no conflicts of interest., (© 2022 The Authors.)

Abstract: Medulloblastomas, especially the sonic hedgehog subgroup, are treated aggressively with surgery and chemoradiotherapy, as they are associated with high local site recurrence rate and poor overall survival. Radiation-induced meningioma is the most common delayed complication of craniospinal irradiation. This needs to be differentiated from meningeal or ependymal metastases as the later need aggressive management. We report one such rare case, in a patient who completed treatment for medulloblastoma 11 years ago, was in remission, and now presented with dural-based lesions., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Aim: To assess the overall survival and determine whether pre-TARE shunt fraction, tumor volume and tumor marker impact the outcome., Methods: This is a retrospective study of 75 patients who were referred for 90Y-glass microsphere radioembolisation by a joint clinic decision between 1 January 2010 and 31 December 2014. All patients underwent pre-TARE CECT and 99mTc-MAA lung shunt fraction (LSF) imaging., Results: Overall survival was 19 months for hepatocellular carcinoma (HCC) and 24 months for metastatic colorectal carcinoma. For hepatocellular carcinoma-LSF higher than 6.51 % was predictive of significantly decreased survival (P value 0.00). A progressive disease in survival was observed as LSF increased from less than 6.51 % to more than 20%. Tumor volume and tumor marker did show correlation with patient outcomes. For metastatic colorectal carcinoma-LSF and tumor marker did not show significant correlation with survival and tumor volume showed significant correlation with survival with P value of 0.049., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Carcinoma of breast with neuroendocrine differentiation is an extremely rare entity, especially in male population. Although the "garden variety" of male breast cancers is often metastatic at presentation, with an aggressive course, there is hardly any literature about neuroendocrine variants. We report a case of a 57-year-old man who had pituitary symptoms, which on 68Ga-DOTANOC PET/CT imaging turned out to be a metastatic lesion, with somatostatin expressing primary in breast and other sites, with histopathological confirmation of neuroendocrine differentiation in breast cancer., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background and Purpose: Highergrade glial neoplasms undergo standard treatment with surgery, radiotherapy, and alkylating agents. There is often a clinical/neuroimaging dilemma in the post-treatment setting to differentiate disease recurrence from treatment-related changes. FET (fluoro-ethyl-tyrosine) PET has emerged as a molecular imaging modality for cases where MR imaging is inconclusive. This study aims to develop a cutoff on FET PET for differentiating true recurrence from post-treatment changes., Methods: We retrospectively analyzed72 patientswith post-treatment grade 3 or 4 brain gliomas. Five to six mCi of 18 F-FET was injected and static imaging of the brain was performed at 20 min. A tumor-to-white matter (T/Wm) ratio was used as semiquantitative parameter. A T/Wm cutoff of 2.5 was used for image interpretation. Imaging findings were confirmed by either histopathologic diagnosis in a multidisciplinary joint clinic or based on follow-up of clinical and neuroimaging findings., Results: Forty-one of 72 patients (57%) showed recurrent disease on FET PET. Thirty-five of them were confirmed to have tumor recurrence; six patients showed post-treatment changes. Thirty-one of 72 patients (43%) showed post-treatment changes on FET PET; 27 were confirmed as post-treatment change and four patients had tumor recurrence on subsequent MR imaging. An optimum T/Wm cutoff of 2.65 was derived based on receiver operating characteristic analysis with a sensitivity of 80% and specificity of 87.5%., Conclusion: Static FET PET can be used as problem-solving imaging modality with a T/Wm cutoff of 2.65 to differentiate late recurrence from post-treatment changes in grade 3 or 4 brain gliomas with equivocal MR features., (© 2021 American Society of Neuroimaging.)

Aim: To assess the prognostic role of metabolic parameters on 18F-FDG PET/CT & correlation with molecular markers in IDH-1 wild-type GBM., Methods: A total of 129 patients with brain lesions showing equivocal findings on baseline MRI who were referred for fluoro-deoxy-glucose PET/CT were analyzed. Of these, 50 underwent surgery/biopsy and postoperative histopathological diagnosis of IDH-1 wild-type GBM. SUVmax, metabolic tumor volume (MTV), total lesion glycolysis (TLG) & T/w ratio was calculated. Median metabolic parameters were used for stratification. Overall survival was calculated using Kaplan-Meier method and was compared using log rank test. P value < 0.05 was considered significant. Multivariate analysis was done using Cox proportional hazard model. Correlation between metabolic parameters and molecular markers was done using Mann-Whitney U test., Results: Median of SUVmax, T/w ratio, MTV, TLG, 18.3, 2.09, 61, 409. Average overall survival (OS) for T/w ratio >2.08 was 5 months, <2.08 was 18 months (P value 0.001). For MTV >61 was 4 months, <61 was 18 months (P value 0.001). Similarly, for TLG >409 was 5 months while for <409 was 19 months (P value 0.001). SUVmax was not significant for OS. In multivariate analysis, age was the statistically significant independent prognostic factor., Conclusion: Metabolic parameters of fluoro-deoxy-glucose PET/CT help in prognosticating IDH-1 wild-type GBM. Higher MiB-1 index correlates with higher T/w ratio and is associated with poor overall survival., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The objective is to evaluate incidental detection of COVID-19 lung involvement in asymptomatic individuals who undergo fluorodeoxyglucose (FDG) positron emission tomography-computerized tomography (PET/CT) scans for oncologic indications., Patients and Methods: The study was conducted in a tertiary care oncology hospital and included patients who were asymptomatic for COVID-19 infection and underwent FDG PET/CT scans for standard oncologic indications between April 15, 2020, and September 30, 2020. Patients who showed CO-RADS category 4/5 changes (high level of suspicion) on the CT chest component of the PET/CT study were considered for analysis. CT severity score, presence of FDG uptake, and maximum standardized uptake value of FDG avid lung involvement were noted and correlated with reverse transcriptase-polymerase chain reaction (RT-PCR) test., Results: 1982 PET/CT scans were performed, 78 (3.9%) patients showed lung changes with high degree of suspicion of COVID-19 pneumonia (CO-RADS 4/5). Hematolymphoid and head-neck cancer were the most common tumor types (23%), and restaging/response evaluation was the most common PET/CT indication. Of the patients who underwent RT-PCR testing, 70% showed a positive result. The mean CT severity score was 6 (standard deviation 5.9) with no significant difference seen between the RT-PCR positive and negative groups. FDG avidity in lung lesions was noted in 41 out 57 (72%) patients. A significant correlation was seen between the RT-PCR positivity and FDG uptake in lung lesions., Conclusion: A small but significant proportion of patients undergoing routine oncologic PET/CT scans showed incidental COVID-19 lung involvement. Lung involvement in these asymptomatic patients showed a low CT severity score in all patients and FDG avidity in majority. Timely detection of such incidental cases can initiate further confirmatory RT-PCR testing and isolation measures that not only influence patient's cancer treatment protocols but also have a larger community impact of limiting the spread of infection., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Indian Journal of Nuclear Medicine.)

Tumor or target heterogeneity (TH) implies presence of variable cellular populations having different genomic characteristics within the same tumor, or in different tumor sites of the same patient. The challenge is to identify this heterogeneity, as it has emerged as the most common cause of 'treatment resistance', to current therapeutic agents. We have focused our discussion on 'Prostate Cancer' and 'Neuroendocrine Tumors', and looked at the established methods for demonstrating heterogeneity, each with its advantages and drawbacks. Also, the available theranostic radiotracers targeting PSMA and somatostatin receptors combined with targeted systemic agents, have been described. Lu-177 labeled PSMA and DOTATATE are the 'standard of care' radionuclide therapeutic tracers for management of progressive treatment-resistant prostate cancer and NET. These approved therapies have shown reasonable benefit in treatment outcome, with improvement in quality of life parameters. Various biomarkers and predictors of response to radionuclide therapies targeting TH which are currently available and those which can be explored have been elaborated in details. Imaging-based features using artificial intelligence (AI) need to be developed to further predict the presence of TH. Also, novel theranostic tools binding to newer targets on surface of cancer cell should be explored to overcome the treatment resistance to current treatment regimens.

Abstract: A 23-year-old man with metastatic osteosarcoma, with disease progression on conventional chemotherapy, was treated with regorafenib, a multikinase inhibitor. After treatment for 6 months with regorafenib, 18F-FDG PET/CT scan demonstrated FDG uptake in a necrotic space-occupying lesion involving tail of pancreas. After imaging, patient described symptoms of epigastric pain with elevated serum amylase and lipase levels, confirming diagnosis of regorafenib-induced pancreatitis, because patient had no other causative factors of pancreatitis. Physicians should be aware of rare and possibly clinically silent adverse effects of tyrosine kinase inhibitors, like acute pancreatitis, and recognize the 18F-FDG PET/CT findings to guide appropriate clinical management., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Chondroblastic osteosarcoma is an uncommon subtype of osteosarcoma, constituting about 25% of all osteosarcoma cases. It has shown high propensity for developing tumor thrombi and thromboembolism, with poor overall survival rate. Differentiation between tumor thrombus and bland thrombus is an important factor in making treatment decisions. 18 F fluorodeoxyglucose positron emission tomography/computed tomography plays a very important role in detecting and differentiating bland thrombus from tumor thrombus., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Indian Journal of Nuclear Medicine.)

Objective: Patients with inoperable multilobar hepatocellular carcinoma (HCC) Barcelona Clinic Liver Cancer (BCLC) stage B, who have failed other liver-directed treatment options, are ideal candidates for transarterial radioembolization (TARE) with Yttrium-90 (Y-90)-labeled glass spheres. There is limited data regarding variables that impact the prognosis and outcome in these patients. 99mTc-MAA scan for lung shunt fraction (LSF) and 18F-FDG PET/CT are performed during initial workup. We, therefore, decided to assess the prognostic impact of LSF and metabolic parameters, such as maximum SUVmax, MTV and TLG in patients undergoing TARE for HCC., Methods: We retrospectively analyzed 64 patients of HCC, between January 2010 and December 2016, deemed suitable for TARE. Pre-TARE LSF was computed on 99mTc MAA scan, and SUVmax, MTV and TLG on fluoro-deoxyglucose positron emission tomography/computed tomography were measured using automated software by 3D region of interest. LSF and PET parameters were stratified using optimal cut-offs derived from receiver operating curve analysis. Survival curves for the groups were estimated using the Kaplan-Meier method and were compared using log-rank test., Results: Overall survival (OS) was 15 months. In univariate analysis, high LSF (greater than 7.19), MTV and TLG were statistically significant and were associated with poor OS. In multivariate analysis, TLG (P value 0.044), MTV (P value 0.290) and LSF (P value 0.010) were independent predictors of outcome, after adjustment for significant univariate variables. However, SUVmax was not statistically significant for OS., Conclusions: LSF, MTV and TLG are significant independent prognostic indicators of outcome in patients undergoing TARE for HCC., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Relapsed high-grade glioma has dismal outcomes. Mebendazole has shown promising activity against glioma in in-vitro and in-vivo studies. Hence, we undertook a phase 1 study to repurpose mebendazole in the treatment of glioblastoma., Methods: We conducted a phase 1 study (accelerated titrated design 4) of mebendazole in patients with recurrent glioblastoma (GBM). Patients eligible for re-irradiation were enrolled in arm A1 (radiation with concurrent temozolomide 75 mg/m 2 daily during the course of radiation+mebendazole) while patients who were ineligible were enrolled in either arm B1 (CCNU 110 mg/m 2 day 1, every 6 weekly + mebendazole) or arm C1 (temozolomide 200 mg/m 2 day 1-5, every 4 weekly + mebendazole). The primary endpoint of phase 1 was to identify the MTD of mebendazole in each combination., Findings: 11 patients were enrolled in the whole study. MTD of mebendazole was not reached in arm A1 and C1 and hence the recommended dose for phase 2 was 1600 mg TDS (4800 mg) per day. The MTD of mebendazole in combination with CCNU was 1600 mg TDS (4800 mg) per day and the dose recommended for phase 2 was 800 mg TDS (2400 mg) per day. The three most common adverse events seen in the study were anemia (n = 9, 81.8%), nausea (n = 7, 63.6%), and fatigue (n = 6, 55.5%)., Interpretation: The recommended phase 2 dose of mebendazole is 1600 mg TDS with temozolomide and temozolomide-radiation combination while the dose of 800 mg TDS needs to be used with single-agent CCNU., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

There is a sudden upsurge in the literature over the last fortnight on strategies to be followed by imaging services during this SARS-CoV-2 global pandemic. This compilation of strategies, experiences, and precautions is intended to support nuclear medicine departments, as they make decisions regarding patient care. These guidelines are a good resource to tackle the current crisis, however, situations such as these may occur again, and long-term readiness measures need to be discussed and implemented., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Indian Journal of Nuclear Medicine.)

National Electrical Manufacturers Association (NEMA) provides guidelines to assess the performance of Positron Emission Tomography (PET). A PET/CT scanner, Discovery IQ, GE Medical systems, Milwaukee, USA was installed in our department which has high a sensitivity PET component. We have performed the NEMA NU-2 2012 quality control tests to evaluate this system on site before clinical use. Performance measurements of the PET scanner were made using the NEMA NU2-2012 procedures for spatial resolution, scatter fraction, sensitivity, count rate loss and random coincidence estimation, Noise Equivalent Count Rate (NECR) and image quality. As per NU2 2012, spatial resolution was measured at 1 cm, 10 cm and 20 cm vertically from the centre and at each of these points resolution was measured at tangential, radial and axial directions. Sensitivity was measured at centre and 10 cm off center vertically from the center. The system sensitivity is reported as an average of the two measured values. Scatter fraction and NECR measurements, Image quality test was also performed. The tangential, radial and axial FWHM were 4.99 mm, 4.20 mm and 4.79 mm at 1 cm off centre, 5.49 mm, 4.69 mm and 4.81 mm at 10 cm off centre and 7.99 mm, 5.07 mm and 4.95 mm at 20 cm off centre respectively. The absolute sensitivity of this scanner was found to be 20.1 cps/kBq. The scatter fraction calculated from the decay method was 37.94% and NECR was 125 kcps. The peak NECR was achieved at activity concentration of 8.7 KBq/ml and the count loss below the peak NECR was found to be 0.68%. Image quality test for, contrast recovery, background variability and lung error residual mean met all specifications. Overall PET performance of Discovery IQ whole-body scanner was satisfactory and the scanner met all the performance specifications required by NEMA 2012., Competing Interests: There are no conflicts of interest., (Copyright: © 2019 World Journal of Nuclear Medicine.)

High-grade gliomas, metastases, and primary central nervous system lymphoma (PCNSL) are common high-grade brain lesions, which may have overlapping features on magnetic resonance (MR) imaging. Our objective was to assess the utility of 18-fluoride-fluoro-ethyl-tyrosine positron emission tomography (FET-PET) in reliably differentiating between these lesions, by studying their metabolic characteristics. Patients with high-grade brain lesions suspicious for glioma, with overlapping features for metastases and PCNSL were referred for FET-PET by Neuroradiologists from Multidisciplinary Neuro-Oncology Joint Clinic. Tumor-to-contralateral white mater ratio (T/Wm) at 5 and 20 min was derived and compared to histopathology. Receiver operating characteristic curve analysis was used to find the optimal T/Wm cutoff to differentiate between the tumor types. T/Wm was higher for glial tumors compared to nonglial tumors (metastases, PCNSL, tuberculoma, and anaplastic meningioma). A cutoff of 1.9 was derived to reliably diagnose a tumor of glial origin with a sensitivity and specificity of 93.8% and 91%, respectively. FET-PET can be used to diagnose glial tumors presenting as high-grade brain lesions when MR findings show overlapping features for other common high-grade lesions., Competing Interests: There are no conflicts of interest.

Aim: With increased clinical indications for positron-emission tomography/computed tomography (PET/CT) and repeated PET/CT scans, there is a need to reduce the radiation burden to the patient, professionals as well as public. This requires a redefining of the workflow and the 18-F-fluorodeoxyglucose (18F-FDG) administered activity. The objective of our study is to observe the impact of strike out reduction of administered activity on the radiation exposure to personnel and public, as well as the absorbed dose to the patient with no compromise on image quality by increasing the image acquisition time., Materials and Methods: Nineteen patients evaluated in this study (11 males, 8 females) were put into two groups, namely, A and B. Patients in Group A ( n = 10) were administered with 18F-FDG equivalent to the recommended dose (7-8 MBq/kg body weight) whereas patients in Group B ( n = 9) were administered with 18F-FDG equivalent to half the recommended dose (3-4MBq/kg body weight). The exposure rates from the patients at the body surface and 100 cm distance were measured immediately and 1 h postinjection., Results: The average surface dose rate and 100 cm dose rate of the adult patients immediately postinjection for patients of Group A were 0.94 ± 0.19 mSv/h and 0.057 ± 0.007 mSv/h, and for Group B were 0.34 ± 0.24 mSv/h and 0.031 ± 0.01 mSv/h., Conclusion: This study suggests that reduction in injected 18F-FDG activity reduces the radiation exposure rate from the patient, absorbed dose to the patient with reportable image quality., Competing Interests: There are no conflicts of interest.

Competing Interests: There are no conflicts of interest.

Purpose: Head and neck paragangliomas (HNPGLs) are rare tumours arising from autonomic nervous system ganglia. Although surgery offers the best chance of complete cure, there is associated morbidity due to the crucial location of these tumours. Radiotherapy arrests tumour growth and provides symptomatic improvement, but has long-term consequences. These tumours express somatostatin receptors (SSTR) and hence peptide receptor radionuclide therapy (PRRT) is now a treatment option. We assessed the molecular, morphological and clinical responses of inoperable HNPGLs to PRRT., Methods: Nine patients with inoperable HNPGL assessed between June 2006 and June 2014 were included. Four patients had a solitary lesion, four had multifocal involvement and one had distant metastases (bone and lungs). The patients were treated with PRRT using (90)Y/(177)Lu-labelled peptides after positive confirmation of SSTR expression on (68)Ga-DOTATOC PET/CT. All patients received two to four courses of PRRT. Subsequent serial imaging with (68)Ga-DOTATOC PET/CT was carried out every 6 months to assess response to treatment. Clinical (symptomatic) response was also assessed., Results: Based on molecular response (EORTC) criteria, four of the nine patients showed a partial molecular response to treatment seen as significant decreases in SUVmax, accompanied by a reduction in tumour size. Five patients showed stable disease on both molecular and morphological criteria. Six out of nine patients were symptomatic at presentation with manifestations of cranial nerve involvement, bone destruction at the primary site and metastatic bone pain. Molecular responses were correlated with symptomatic improvement in four out of these six patients; while two patients showed small reductions in tumour size and SUVmax. The three asymptomatic patients showed no new lesions or symptomatic worsening., Conclusion: PRRT was effective in all patients, with no disease worsening seen, either in the form of neurological symptoms or distant spread. Though these are preliminary results, PRRT shows promise as a good treatment option for HNPGL, and hence study in a larger patient cohort is essential to establish its place in the management algorithm.

Companion diagnostics (CDx) is a positive attempt in the direction of improving the drug development process, especially in the field of oncology, with the advent of newer targeted therapies. It helps the oncologist in deciding the choice of treatment for the individual patient. The role of CDx assays has attracted the attention of regulators, and especially the US Food and Drug Administration developed regulatory strategies for CDx and the drug-diagnostic codevelopment project. For an increasing number of cancer patients, the treatment selection will depend on the result generated by a CDx assay, and consequently this type of assay has become critical for the care and safety of the patients. In addition to the assay-based approach, molecular imaging with its ability to image at the genetic and receptor level has made foray into the field of drug development and personalized medicine. We shall review these aspects of CDx, with special focus on molecular imaging and the upcoming concept of Theranostics.

Painful bone lesions, both benign and metastatic, are often managed using conventional analgesics. However, the treatment response is not immediate and is often associated with side-effects. Radionuclide therapy is used for pain palliation in bone metastases as well as some benign neoplasms. Endoradiotherapy has direct impact on the pain-producing bone elements, and hence, response is significant, with minimal or no side-effects. A new potential compound for endoradiotherapy is [(177)Lu]BPAMD. It combines a highly affine bisphosphonate, covalently bridged with DOTA through an amide bond, with the low-energy β(-) emitting therapeutic radiolanthanide (177)Lu. For routine chemical application, an automated synthesis of this radiopharmaceutical and a Kit-type labeling procedure appears to be a basic requirement for its good manufacturing practice (GMP) based production. A Kit formulation combining BPAMD, acetate buffer, and ethanol resulted in almost quantitative labeling yields. The use of ethanol and ascorbic acid as quenchers prevented radiolysis over 48 hours. An automated synthesis unit was designed for the production of therapeutic doses of [(177)Lu]BPAMD up to 5 GBq. The procedure was successfully applied for patient treatments.

Introduction: Targeted therapeutic agents are indicated in metastatic lung cancers. These being receptor specific therapies, manifestation of response can be best assessed by estimating the metabolic activity of tumor, rather than the size. This retrospective analysis studied metabolic and morphological response on Positron Emission Tomography (PET) and Computed Tomography (CT), respectively to these agents., Materials and Methods: Thirty-one patients (23 males, 8 females with an age range of 42-77 years) with Epidermal Growth Factor Receptor (EGFR) positive metastatic lung cancer on Gefitinib, who underwent PET/CT, at baseline and at 4-6 weeks, were assessed by Response Evaluation Criteria In Solid Tumors [RECIST] 1.1 and European Organization for Research and Treatment of Cancer (EORTC) criteria., Results: Concordance between RECIST 1.1 and EORTC was seen in 26 (83.7%) patients. Discordance was seen in 5 (16.3%) patients. In patients with discordance, the results were confirmed by follow-up imaging. Metabolic EORTC criteria changed the disease status from stable disease to partial response (3 out of 5) and progressive disease (2 out of 5) in these five patients., Conclusions: Metabolic criteria using PET/CT could accurately predict response as well as disease progression early in the course of targeted therapy, compared to morphologic criteria. In addition, early metabolic response assessment can predict refractoriness of therapy.

Recognition of patterns has always been extremely important in cross-sectional imaging. Peritoneal involvement, both primary and as dissemination from abdominopelvic malignancies, is manifested in different forms, purely because of anatomical complexity. We studied series of peritoneal involvement by (18)F-fluorodeoxyglucose positron-emission tomography/computed tomography fusion imaging and derived patterns of tracer uptake on maximum intensity projection and cross-sectional fusion images.

Majority of patients with head and neck cancer are treated with combined treatment regimes such as surgery, radiation therapy, and chemotherapy. The loss of structural symmetry and imaging landmarks as a result of therapy makes post-treatment imaging a daunting task on conventional modalities like computed tomography (CT) scan and magnetic resonance imaging (MRI) as well as on 18 Fluorine-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F FDG PET/CT). Combined multimodality treatment approach causes various tissue changes that give rise to a spectrum of findings on FDG PET/CT imaging, which are depicted in this atlas along with a few commonly encountered imaging pitfalls. The incremental value of FDG PET/CT in detecting locoregional recurrences in the neck as well as distant failures has also been demonstrated.

Metastatic involvement of the heart is a rare occurrence and remains undiagnosed until autopsy. In some instances, patients may have cardiac symptoms, leading to ante-mortem diagnosis. Although most primary cancers have been documented to metastasize to heart, the existing literature on cancers of upper aero-digestive tract is an exception, with only a few reports. We report four cases of upper aero-digestive tract cancers, three of which arise from oral cavity, one from lower esophagus, metastasising to the myocardium, detected on 18 F - Fluoro-deoxy-glucose Positron Emission Tomography/Computed Tomography (FDG PET/CT) study , in the absence of related symptoms.

Filtered Back-Projection (FBP) has become an outdated image reconstruction technique in new-generation positron emission tomography (PET)/computed tomography (CT) scanners. Iterative reconstruction used in all new-generation PET scanners is a much improved reconstruction technique. Though a well-calibrated PET system can only be used for clinical imaging in few situations like ours, when compromised PET scanner with one PET module bypassed was used for PET acquisition, FBP with sinogram correction proved to be a better reconstruction technique to minimize streak artifact present in the image reconstructed by the iterative technique.

Primary carcinoma of gall bladder is a highly aggressive malignancy, most often detected in late stage in majority of the affected patients. It commonly spreads to the adjacent liver parenchyma and, via lymphatics, to mesenteric nodes. Extra-abdominal metastatic sites are extremely rare, with lung being the commonest site. We report a rare occurrence of isolated asymptomatic bone marrow metastases from gall bladder cancer, in the absence of locoregional adenopathy, detected on whole-body F-FDG PET/CT at initial staging.

Mesenteric lymphomas are commonly seen as bulky hypermetabolic nodal masses on F-FDG PET/CT. Very rarely, these are seen as mesenteric haziness due to localized hyperattenuation of fat, known as "misty mesentery", which morphological imaging-wise has other differentials as well. We report a unique imaging finding of segmental misty mesentery with hypermetabolic mesenteric nodes on FDG PET/CT in a patient who was kept on observation due to inconclusive biopsy, which on follow-up imaging progressed to extensive lymphomatous involvement. Thus, in retrospect, this imaging feature on baseline PET/CT was diagnostic for mesenteric lymphoma.