Radiation doses to mediastinal organs at risk in early-stage unfavorable Hodgkin lymphoma- a risk stratified analysis of the GHSG HD17 trial

Michael Oertel; Dominik Hering; Christian Baues; Christopher Kittel; Michael Fuchs; Jan Kriz; Kai Kröger; Dirk Vordermark; Klaus Herfarth; Rita Engenhart-Cabillic; Peter Lukas; Uwe Haverkamp; Peter Borchmann; Hans Theodor Eich

doi:10.3389/fonc.2023.1183906

Radiation doses to mediastinal organs at risk in early-stage unfavorable Hodgkin lymphoma- a risk stratified analysis of the GHSG HD17 trial

Front Oncol. 2023 May 5:13:1183906. doi: 10.3389/fonc.2023.1183906. eCollection 2023.

Authors

Affiliations

¹ Department of Radiation Oncology, University Hospital Muenster, Muenster, Germany.
² Department of Radiation Oncology and Cyberknife Center, University Hospital of Cologne, Cologne, Germany.
³ Department of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne, Dusseldorf, University Hospital of Cologne, Cologne, Germany.
⁴ Department of Radiation Oncology, Alexianer Clemenshospital Muenster, Muenster, Germany.
⁵ Department of Radiation Oncology, University Hospital Halle (Saale), Halle (Saale), Germany.
⁶ Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.
⁷ Department of Radiotherapy and Radiation Oncology, University Hospital Giessen-Marburg, Marburg, Germany.
⁸ Department of Radiooncology, Medical University Innsbruck, Innsbruck, Austria.

Abstract

Introduction: The German Hodgkin Study Group (GHSG) HD17 trial established the omission of radiotherapy (RT) for patients with early-stage unfavorable Hodgkin lymphoma being PET-negative after 2 cycles of BEACOPP escalated plus 2 cycles of ABVD. This patient group reveals heterogeneity in characteristics and disease extent which prompted us to perform a decisive dosimetric analysis according to GHSG risk factors. This may help to tailor RT individually balancing risks and benefits.

Methods: For quality assurance, RT-plans were requested from the treating facilities (n= 141) and analyzed centrally. Dose-volume histograms were scanned either paper-based or digitally to obtain doses to mediastinal organs. These were registered and compared according to GHSG risk factors.

Results: Overall, RT plans of 176 patients were requested, 139 of which had dosimetric information on target volumes within the mediastinum. Most of these patients were stage II (92.8%), had no B-symptoms (79.1%) and were aged < 50 years (89.9%). Risk factors were present in 8.6% (extranodal involvement), 31.7% (bulky disease), 46.0% (elevated erythrocyte sedimentation rate) and 64.0% (three involved areas), respectively. The presence of bulky disease significantly affected the mean RT doses to the heart (p=0.005) and to the left lung (median: 11.3 Gy vs. 9.9 Gy; p=0.042) as well as V5 of the right and left lung, respectively (median right lung: 67.4% vs. 51.0%; p=0.011; median left lung: 65.9% vs. 54.2%; p=0.008). Significant differences in similar organs at risk parameters could be found between the sub-cohorts with the presence or absence of extranodal involvement, respectively. In contrast, an elevated erythrocyte sedimentation rate did not deteriorate dosimetry significantly. No association of any risk factor with radiation doses to the female breast was found.

Conclusion: Pre-chemotherapy risk factors may help to predict potential RT exposure to normal organs and to critically review treatment indication. Individualized risk-benefit evaluations for patients with HL in early-stage unfavorable disease are mandatory.

Keywords: dosimetry; involved-field radiotherapy; involved-node radiotherapy; radiation oncology; radiation treatment; survivorship.

Grants and funding

HE and MO report support of the present work from the German Cancer Aid (Grant number: 70112331). KH reports grants or contracts from Roche Pharma.