Patients with early-stage Hodgkin lymphoma (ES-HL) who undergo combination treatment with chemotherapy and radiotherapy may experience late adverse effects, including the possibility of radiation-related cardiovascular disease.
A team of researchers recently sought to predict the risk of developing radiation-related cardiovascular disease (CVD) with the aim of providing more information that could guide future decisions regarding radiotherapy for patients with ES-HL. Their findings were published in the Journal of Clinical Oncology.
The researchers used data from 571 patients enrolled in the UK National Cancer Research Institute Lymphoma Study Group RAPID trial. The patients had undergone 3 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) followed by fluorodeoxyglucose-positron emission tomography (PET), and were randomly assigned to receive involved field radiotherapy (IFRT) or no further treatment.
IFRT was used to treat only the extent of disease detected by CT before chemotherapy. Of the 209 patients whose PET scans were negative, 183 received IFRT, and 129 of 145 patients whose PET scans were positive received IFRT.
The 30-year absolute excess radiation-related risk to individual patients was less than 0.5% in 67% of patients and greater than 1% in 15%. “If IFRT were given selectively to the 50% of PET-negative patients with the lowest predicted radiation-related risks, then the average predicted 30-year absolute excess radiation-related cardiovascular risk for these patients would be 0.11%,” the researchers reported.
Although the overall risk was relatively small, higher doses increased the risk of radiotherapy-related cardiovascular disease, the researchers found.
Ultimately, this means that the benefit of radiotherapy may outweigh the risks for most patients with ES-HL. Omitting radiotherapy could increase their risk of relapse, which would in turn warrant more treatment. But it may be preferable to reduce the dose or omit radiotherapy despite the risk of relapse because of the damage that high-dose radiation can inflict on some patients’ hearts.
This study benefitted from having a high number of patients with completed dosimetry, but not all of the dosimetry was based on their individual anatomy. However, the researchers do not believe that that substantially affects the average cardiovascular doses and predicted risks. And while the researchers’ method was based on the best possible epidemiologic evidence that is currently available, “the method used to predict radiation-related CVD has not been prospectively validated, as 20 additional years of follow-up would be required to assess the accuracy of the predictions.”
Disclosure: Some study authors declared an affiliation with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Cutter DJ, Ramroth J, Diez P, et al. Predicted risks of cardiovascular disease following chemotherapy and radiotherapy in the UK NCRI RAPID Trial of positron emission tomography-directed therapy for early-stage Hodgkin lymphoma. J Clin Oncol. 2021;39(32):3591-3601. doi:10.1200/JCO.21.00408