The publication of the GHSG HD10 trial changed the treatment paradigm for early-stage, favorable Hodgkin lymphoma (HL). Two cycles of ABVD followed by 20 Gy of involved-field radiotherapy (IFRT) has become a widely accepted treatment strategy for these patients. However, PET/CT is now increasingly used for response assessment after chemotherapy, and IFRT has largely been replaced by involved-site radiotherapy (ISRT). In this study, we describe our experience of 2 cycles of ABVD followed by PET/CT assessment, and ISRT to 20 Gy for patients with early-stage, favorable HL.
With IRB approval, records of 20 patients (11 females, 9 males) with early-stage, favorable HL per the GHSG criteria, treated between 2008-2015, were reviewed. All patients underwent PET/CT for initial staging and for restaging after 2 cycles of ABVD. This was followed by ISRT to 20 Gy in 10 fractions, using 3-dimensional conformal technique. PET-response after 2 cycles of ABVD was independently assessed by a nuclear medicine physician with Deauville score assignment. Actuarial rates of relapse-free survival (RFS) and overall survival (OS) were calculated. RFS was defined as the time from start of chemotherapy to relapse or death, whichever occurred first.
The median age at diagnosis was 33 years (range 20-82). All but 2 patients were without B symptoms, and 50% had 1 site of disease. Median ESR was 10 (range 1-16). Median maximal tumor dimension was 38 mm (range 12-80 mm). After 2 cycles of ABVD, 95% of patients had a Deauville score of 1-2, and 1 patient had a score of 3. Median follow-up is 46.9 months. As of this analysis, all patients are alive without disease. One patient had an out-of-field relapse, but was salvaged with chemotherapy followed by autologous stem cell transplant. This patient had 80 mm disease at time of diagnosis and a Deauville 2 score after chemotherapy. The 4-year RFS rate is 90.9% (95% CI: [50.8, 98.7]). Figure 1 shows RFS in this 20-patient cohort.
Our results showed that with careful patient selection based on initial disease characteristics and PET-response to chemotherapy, the use of a more restricted radiotherapy treatment volume of ISRT to 20 Gy following ABVD x 2 is associated with an excellent outcome with no local recurrences or marginal misses.