Abstract

PURPOSE/OBJECTIVE(S): There is no standard treatment for nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). Although response by positron emission tomography (PET) for classic Hodgkin lymphoma (cHL) has allowed for response-adapted treatment, similar approaches for NLPHL have not been developed. This is in part due to the lack of data for PET response to treatment. Therefore, we sought to investigate PET responses to management for NLPHL.MATERIALS/METHODS: We retrospectively identified 47 patients who were diagnosed with or treated for NLPHL between 2001-2018 at a single institution and underwent a staging PET. We recorded clinical data and PET metrics for patients who received various forms of management, including chemotherapy (CT), radiation therapy (RT), combined modality therapy (CMT?=?CT+RT, with rituximab in a subset), rituximab monotherapy, and observation after excision. Metabolic response was scored according to the Deauville 5-point scale criteria, with complete metabolic response defined as a score 1-3.RESULTS: We identified 47 patients with median age of 26 (IQR?=?17-50). They predominantly were male (74.5%) and had early stage (23.4% I, 36.2% II) versus advanced stage (29.8% III, 10.5% IV) NLPHL. The majority of patients had their immunoarchitectural pattern scored (n?=?36, 76.6%), with typical pattern (A/B) being the most frequent type (58.3%). The median follow-up was 5.7 years (IQR?=?2.3-9.3). Overall survival was 100% at 5 years and 92.3% at 10 years. Primary management included CMT (n?=?10, 21.3%; with rituximab in a subset n?=?1, 10.0%), CT alone (n?=?22, 46.8%; with rituximab in a subset n?=?5, 22.7%), RT alone (n?=?8, 17.0%), rituximab alone (n?=?3, 6.4%), and observation after excision (n?=?4, 8.5%). On baseline PET, median SUVmax was 10.7 (range?=?1.7-35.4). Of the 10 patients who received CMT, the complete metabolic response rates were 42.9% at interim-chemotherapy PET and 75% at post-chemotherapy PET, which improved to 100% after consolidative radiotherapy. There was no difference in complete metabolic response rate to chemotherapy for typical versus variant pattern (P?=?0.60). Of the 22 patients who received CT alone, 66.7% had a complete metabolic response at the interim PET and 72.7% at the end of chemotherapy. For RT, rituximab alone, and observation, the complete metabolic response rates at median 3 months (range 1-5 months) after treatment were 87.5%, 66.7%, 75.0%, respectively.CONCLUSION: Based on our cohort, we found that patients with NLPHL had a lower complete metabolic response to CT (75%) compared to cHL (85-90%) and PET-response was improved following RT for those receiving CMT. There was no significant difference in PET-response for those with variant versus typical immunoarchitectural patterns. Our findings will allow for the development of PET response-adapted therapy for NLPHL.

View details for DOI 10.1016/j.ijrobp.2023.06.1699

View details for PubMedID 37785523