Early replacement of CT scanning by abdomino-pelvic ultrasound as a safe alternative in the follow-up of patients with germ cell tumors.

Abstract

420 Background: Late relapse in patients with germ cell tumors (GCT) are rare events. As there is no consensus for follow-up (FU) protocols, it is unclear if shorter duration of CT scanning is safe while reducing unnecessary exposure to radiation. Methods: At the completion of their treatment, all patients with Stage I, metastatic good or intermediate prognosis seminoma and non-seminoma (NSGT) underwent physical exam, serum tumor markers and imaging at regular intervals. We retrospectively identified 2 groups of patients with different FU strategies: those with regular CT scan of the chest, abdomen and pelvis for 3 years or less, then followed by abdomino-pelvic ultrasound (Group 1); and those with CT scanning continued beyond 3 years (Group 2). Results: Between December 1997 and March 2016, 203 patients were included: 80 (39.4%) in Group 1 and 123 (60.6%) in Group 2. The mean duration of FU was 6.7 ± 2.4 years in Group 1 and 8.1 ± 2.5 years in Group 2 (p < 0.001). After year 3 the median number of abdomino-pelvic ultrasound in Group 1 was 5 (4-6) and the median number of CT scanning in Group 2 was 6 (5-8). Five (2.4%) relapses were identified: 1 in Group 1 and 4 in Group 2. Relapse was revealed by symptoms in 2 patients with NSGT (1 in each group) who had been lost for FU. Three patients underwent local treatment (2 surgeries for teratoma relapses and 1 radiotherapy for seminoma relapse) and are still disease-free. International prognostic factors score was low and intermediate for the first 2 patients, very low for seminoma relapse and low for teratoma relapses. Conclusions: Patient follow-up by regular abdomino-pelvic ultrasound instead of CT scan appears a feasible alternative after the third year in patients with GCT, with no excess risk of incurable relapses. Prospective validation is required.