Infradiaphragmatic Hodgkin lymphoma: a large series of patients staged with PET-CT

Dissemination patterns of Hodgkin lymphoma using a probability network model based on [18F]-FDG PET/CT

PURPOSE

The preferred hypothesis for the dissemination patterns of Hodgkin lymphoma (HL) is the contiguity hypothesis. However, this hypothesis is based on studies performed before the advent of [18F]-FDG PET/CT which is now the established reference for HL staging. This study aims to extract the dissemination patterns of HL using [18F]-FDG PET/CT and a probability network model.

METHODS

We retrospectively analyzed [18F]-FDG PET/CT performed for initial staging of patients with classical HL. The HL involvement status (presence of absence) was reported for 19 supra- and infra-diaphragmatic lymph node regions and 4 extranodal regions (lung, spleen, liver, and osteo- medullary). The analysis of HL dissemination was carried out using HL involvement status for all regions through 3 distinct methods: comparison of nearby lymph node regions, correlation assessment between all regions and relationship strength between all regions using Ising network model.

RESULTS

A total of 196 patients were included. Our results showed strong relationships between nearby involved lymph node regions (for example between the left pelvic and the abdominal lymph node regions (relationship strength = 0.980)) and between more distant regions (for example between right and left axillary lymph node regions (strength = 0.714)). Furthermore, involvement of the infra-diaphragmatic lymph node regions was significantly correlated with Ann Arbor stage IV (phi = 0.56, p < 0.001).

CONCLUSION

This study confirms the hypothesis of lymphatic dissemination of HL in a contiguous mode, with additional links between more distant regions. These predictable dissemination patterns could be useful for the initial staging assessment of patients with HL using [18F]-FDG PET/CT.

Outcome of Patients With Early-Stage Infradiaphragmatic Hodgkin Lymphoma: A Comprehensive Analysis From the German Hodgkin Study Group

Purpose The prognostic effect of isolated infradiaphragmatic involvement in Hodgkin lymphoma (HL) is controversial, and there are little data about patients treated with current therapies. Therefore, we performed a risk factor analysis to focus on isolated nodal infradiaphragmatic disease in patients treated within the German Hodgkin Study Group trials HD13 (clinical trial information: ISRCTN63474366) and HD14 (clinical trial information: ISRCTN04761296) for early-stage HL. Patients and Methods Characteristics and outcomes of patients who had infradiaphragmatic HL were compared with patients who had supradiaphragmatic disease. Progression-free survival (PFS) and overall survival (OS) were estimated according to Kaplan-Meier methods and were compared between groups using the log-rank test and Cox proportional hazards regression, which was also applied for multivariable analyses that adjusted for relevant baseline characteristics. Results Of 2,903 qualified patients, 223 (7.7%) were diagnosed with isolated nodal infradiaphragmatic disease. In general, these patients were older, had a poorer performance status, were more often male, and had the nodular sclerosis subtype less often than those with supradiaphragmatic disease. After a median follow-up time of 51 months, PFS and OS were significantly worse in patients with infradiaphragmatic disease (5-year PFS and OS, 80.1% and 91.5% v 91.2% and 97.6% in patients with supradiaphragmatic disease; each P < .001). In multivariable analyses, infradiaphragmatic HL remained a significant risk factor in terms of PFS (hazard ratio [HR], 1.5; 95% CI, 1.04 to 2.2; P = .03) and OS (HR, 2.0; 95% CI, 1.2 to 3.5; P = .01). However, inferior PFS and OS could not be observed among those patients treated with the more intensive chemotherapy (two cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine [ABVD] in HD13, and two cycles of escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone [BEACOPP_escalated] plus two cycles of ABVD in HD14; all patients received 30 Gy of involved-field radiotherapy). Conclusion Early-stage HL that presents with infradiaphragmatic disease only represents a distinct patient group with an inferior outcome. However, this adverse outcome can be outweighed by appropriate combined modality treatment.