Karin Nielsen1, Maja V. Maraldo1, Anne Kiil Berthelsen1, Annika Loft2, Peter Meidahl Petersen1, Marianne C. Aznar3, Ivan Richter Vogelius1, Peter Brown4, Lena Specht1
1 Department of Clinical Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Denmark, 2 Department of Clinical Physiology, Nuclear Medicine and PET, PET and Cyclotron Unit 3982, Rigshospitalet, University of Copenhagen, Denmark, 3 Manchester Cancer Research Centre, Division of Cancer Sciences, University of Manchester, Manchester, UK, 4 Department of Haematology, Rigshospitalet, University of Copenhagen, Denmark
Purpose/Objective: Involved node radiotherapy (INRT) for early stage classical Hodgkin lymphoma (ESHL), in combination with chemotherapy, has reduced the irradiated volume and thereby the risk of late effects from radiotherapy (RT). Here, we present the pattern of relapse in a cohort of 193 consecutive ESHL patients treated with INRT from 2005 to 2014 at our institution.
Materials/methods: For all patients, initial disease characteristics and treatment information were collected from medical files, with follow-up data collected through national registries. Survival estimates were calculated using the Kaplan-Meier method (overall survival (OS), progression free survival (PFS) defined as time from date of diagnosis to progression or death of any cause, and time to progression (TTP) defined as time from date of diagnosis to progression or death due to HL).
Results: Of the 193 ESHL patients; eight had primary refractory disease (not further analysed). Patient and treatment characteristics are shown in table 1. Six patients were lost to follow-up, and 25 patients died (one from HL). Median follow up time for patients still alive was 99 months (range: 20–160). Ten patients had a relapse (crude relapse rate of 5.2%) after a median of 36 months (range: 7–113). Five relapsed in initially involved nodes: two in initially involved bulky (defined as > 5 cm) and irradiated nodes and three (one bulky) in previously unirradiated nodes (two patients treated without radiotherapy, one in an initially involved node which had unintentionally been left out of the irradiated volume). Of the five patients who relapsed outside the primary involved nodes, two had initially bulky disease and three did not. The 5- and 10-year survival estimates were: OS of 90.4% (95% CI, 86.1–94.7%) and 84.4% (95% CI, 78.1–90.7%); PFS of 87.6% (95% CI, 82.7–92.5%) and 79.4% (95% CI, 72.3–86.5%); and TTP of 96.0% (95% CI, 93.1–98.9%) and 92.6% (95% CI, 87.7–97.5%), respectively. Local control rate with radiotherapy was 98.8% (95% CI, 97.0–100.0%) at both 5- and 10 years.
Conclusion: The use of INRT in the treatment of ESHL provides excellent local lymphoma control, consolidating the high survival rates. In this small material bulky disease does not appear to be a risk factor for relapsed disease, but the significance of bulky disease in relation to relapse needs further investigation.