Kobe C et al. (2008) Positron emission tomography has a high negative predictive value for progression or early relapse for patients with residual disease after first-line chemotherapy in advanced-stage Hodgkin lymphoma. Blood 112: 3989–3994

One of the main goals of treatment for patients with Hodgkin lymphoma is to reduce treatment toxicity while maintaining its efficacy. The HD15-PET trial performed by the German Hodgkin Study Group (GHSG) evaluated the negative predictive value of 18FDG-PET in patients with HL who were treated with chemotherapy.

This substudy of the HD15 trial included patients with Hodgkin lymphoma who had received 6–8 cycles of cyclophosphamide, adriamycin, etoposide procarbazine, prednisone, vincristine and bleomycin (BEACOPP). Of 817 patients available for this interim analysis, 311 patients had residual tumor ≥2.5 cm as assessed by CT, among whom 66 had 18FDG-PET results indicative of active disease (PET-positive) and 245 had 18FDG-PET results indicative of inactive disease (PET negative). PET-positive patients received 30 Gy radiotherapy to residual masses, while PET-negative patients were followed up without radiotherapy. Progression-free survival 12 months after 18FDG-PET was 85% and 96% for PET-positive and PET-negative patients, respectively (P = 0.011). The negative predictive value of PET was defined as the proportion of PET-negative patients without relapse, progression, or radiotherapy within the 12 months after 18FDG-PET, and its value was 94% (range, 91–97%).

The authors suggest that PET-negative patients with HL do not need to receive radiotherapy after chemotherapy, and that omission of radiotherapy does not increase the risk for early relapse or progression.