RESUMO
With the increasing use of 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) scans in oncology, the finding of thyroid incidentalomas, also popularly described as PET-associated incidental neoplasms (PAINs) of the thyroid gland is not unusual. The 18F-FDG PET-CT scans of all patients who underwent imaging for indications other than thyroid malignancy at our tertiary care center between January 1 and December 31, 2017, were retrospectively reviewed for PAINs of the thyroid. A total of 1737 18F-FDG PET-CT scans were done at our center in the year 2017. 288 thyroid incidentalomas were detected in the said period; the rate of PET-CT-detected thyroid incidentalomas being 16.58%, focal incidentalomas among them being 11.7%. Only 29 out of 204 patients (14.21%) with focal thyroid incidentalomas in our cohort underwent an aspiration cytology and/or ultrasound. The rate of malignancy among the PET detected focal thyroid incidentalomas in the cohort of patients with a proven diagnosis was 10.34%. Our study highlights the challenges in the evaluation and management of PAIN in a tertiary care oncology setting. None of the factors studied including nodule size and standardized uptake value predicted the risk of malignancy. Clinicians specializing in the management of thyroid nodules need to understand the clinical significance of the PAIN, and we hope that our unique experience adds to the limited clinical information available in this regard.
RESUMO
BACKGROUND: Combination chemotherapy ABVD (doxorubicin, bleomycin, vinblastine and dacarabazine) cures â¼70% of patients with advanced Hodgkin's lymphoma (aHL, stages IIB, III and IV) while more toxic escalated BEACOPP (EB, combination of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine and prednisolone) increases cure rates to 85%. Patients with a positive interim positron emission tomography-computerized tomography (PET-CT) scan after two cycles (PET-2) of ABVD have very poor outcomes with continued ABVD. Intensifying therapy with EB in PET-2-positive patients ('response-adapted therapy') may improve cure rates, whereas the negative patients can continue ABVD alone. PATIENTS AND METHODS: Eligible patients with newly diagnosed aHL received two cycles of ABVD and underwent PET-2 (scored with semi-quantitative 5-point visual criteria, 'Deauville score'). PET-2-negative patients continued four additional cycles of ABVD, whereas PET-2-positive patients received four cycles of EB. A phase II sample size of 50 was estimated keeping the lower and higher proportion of rejection of the event-free survival (EFS) as 70% and 85%, respectively. RESULTS: Fifty patients [median age 28 (12-60) years; male : female: 39 : 11; stages: IIB-3 (6%), III-29 (58%) and IV-18 (36%); International Prognostic Score (IPS): 0-3: 34 (68%); 4-7: 16 (32%)] were enrolled; 49 underwent PET-2. Eight (16%) were PET-2-positive, whereas 41 (84%) were negative. Forty-seven were evaluable for EFS and all 50 for overall survival (OS). The 2-year EFS was 76% (95% CI: 68-83) and OS was 88% (95% CI: 82-94). PET-2 was strongly prognostic-2-year EFS, negative versus positive: 82% versus 50%; P = 0.013. CONCLUSION: PET-2 response-adapted strategy could not achieve EFS of 85% in aHL. However, escalated therapy improved outcomes in PET-2-positive patients compared with historical data. TRIAL REGISTRATION: CTRI/2012/06/002741 (http://www.ctri.nic.in) and NCT01304849 (http://www.clinicaltrials.gov).
