Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer.

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.

Evaluation of treatment response by Hopkins criteria on 18 F FDG PET-CT in patients of non-small cell lung cancer and its comparison with PERCIST response criteria.

AIM: To assess treatment response on FDG PET-CT in NSCLC patients by visual Hopkins score compared to PERCIST criteria and its potential for prognostication (or its correlation with survival). METHODS: Forty-four NSCLC patients with baseline and post-treatment FDG PET-CT scans were included, and interpreted using Hopkins and PERCIST criteria classifying patients into responders and non-responders. PERCIST-based CMR and PMR, and Hopkins Scores 1,2,3 were classified responders. PERCIST-based SD and PD and Hopkins scores 4,5 were classified as non-responders. Patients were followed upto 24 months after treatment completion. Cohen kappa for inter-criteria agreement and Kaplan Meir curve for overall survival (OS) analysis done. RESULTS: Out of 44 patients, PERCIST classified 27 (61.3%) as responders and 17 (38.6%) as non-responders, whereas Hopkins classified 12 patients (27.3%) as responders and 32 (72.7%) as non-responders. Inter-criteria agreement was low (kappa=0.19) with discordance in 45.5% of patients. Eighteen of 20 discordant cases were non-responders on Hopkins and responders on PERCIST, of which 88.8% were non-responders on follow-up as predicted by Hopkins. PERCIST responders had OS of 96.4% and 64.3% at 9 and 24 months, respectively, while non-responders OS was 93.5% and 40.2% at 9 and 24 months, respectively ( P -value = 0.049). However, responders on Hopkins had OS of 100% at 24 months, whereas non-responders had OS of 93.5% and 51.5% at 9 and 24 months, respectively ( P -value = 0.232). CONCLUSION: Semi-quantitative PERCIST and visual Hopkins criteria show low inter-criteria agreement, with visual criteria better-predicting survival in patients of NSCLC.

Mimicker of Osteoblastic Skeletal Metastasis on 18 F-FDG PET/CT Scan in a Case of Primary Mediastinal Germ Cell Tumor.

ABSTRACT: Primary mediastinal germ cell tumors are uncommon tumors, of which the nonseminomatous type is more likely to metastasize than the seminomatous type. Primary mediastinal germ cell tumors may also present with superior vena cava obstruction. Here, we present this case of primary mediastinal germ cell tumor with superior vena cava obstruction causing dilatation of collaterals in dorsal intravertebral venous plexus, which strongly mimics sclerotic skeletal lesions/metastasis on a Contrast-enhanced CT scan and also appears FDG avid on PET scan. Herein, we can differentiate the two by just a simple review of plain CT scan image.

Post-COVID-19 Unusual Inflammatory Syndromes Detected on 18F-FDG PET/CT Scan.

ABSTRACT: SARS-CoV-2 is primarily known to cause respiratory symptoms. However, in this global COVID-19 pandemic, we have come across many extrapulmonary manifestations during and in the immediate post-COVID phase such as gastrointestinal symptoms, kidney and liver injury, myocardial dysfunction and acute coronary syndromes, and neurological, thromboembolic, dermatological, and musculoskeletal disorders. We present 2 such unusual cases of post-COVID complications-diffuse panniculitis and inflammatory myositis, as well as their clinical and FDG PET/CT imaging features.

Incidental Detection of Mandibular Metastasis in Renal Cell Carcinoma on 99mTc-MIBI Scan.

ABSTRACT: MIBI scintigraphy is the most widely used modality to identify parathyroid adenomas preoperatively. However, MIBI is also known to accumulate in multiple benign and malignant lesions. In renal cell carcinoma, 30% of the patients present with distant metastasis, commonly lungs and bone; however, jaw bone metastases are extremely rare (<1% of oral malignancies). Here we present a rare case of MIBI-avid mandibular metastasis in bilateral renal cell carcinoma on 99mTc-MIBI scintigraphy. Thus, we emphasize on careful interpretation of 99mTc-MIBI scans, which in addition to parathyroid adenomas can incidentally detect concurrent malignant lesions.

Role of 18F-Fluorodeoxyglucose Positron Emission Tomography-Contrast-Enhanced Computed Tomography in Detection of Early Recurrence with Peritoneal Disease in a Case of Adrenocortical Carcinoma.

Adrenocortical carcinoma (ACC) is an uncommon and highly aggressive malignancy with a poor prognosis. Common sites of metastasis are lung, liver, and lymph nodes. We present a case of ACC in a 54-year-old female with an early disease recurrence of unusual hypervascular peritoneal metastatic abdominal-pelvic deposits detected on 18F-fluorodeoxyglucose positron emission tomography-contrast-enhanced computed tomography scan.

An Unusual Case of Urothelial Carcinoma of Bladder with Metastasis to Brain and Skeletal Muscles Evaluated on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Urothelial or transitional cell carcinoma is the most prevalent variant of urinary bladder carcinoma worldwide occurring in both men and women. There are a very few cases described in the literature with metastasis to skeletal muscles and even fewer cases with metastatic site in the brain. We present a case of high-grade urothelial carcinoma with metastasis to the left temporal lobe as well as multiple inter- and intra-muscular deposits in the left thigh.

An Unusual Case of Bilateral Ureteric Metastasis on PSMA PET-CT Scan in Carcinoma Prostate.

ABSTRACT: The most common locations for metastasis in adenocarcinoma of the prostate gland are lymph nodes, bone, lung, and liver. The involvement of the ureter as a site of metastasis in prostate carcinoma is quite rare in literature. Here we present a case involving bilateral ureters along with bilateral vesicoureteric junctions in a known case of prostate adenocarcinoma.