Improved therapies, incomplete data: late toxicity after modern classical Hodgkin Lymphoma radiotherapy

Radiotherapy, given after a limited amount of chemotherapy, remains a cornerstone in the treatment of most patients with limited-stage classical Hodgkin lymphoma (HL) and contributes significantly to the high cure rates observed.However, longterm survivors are at risk for a spectrum of late treatmentrelated toxicities, among which second malignancies represent a major cause of morbidity and mortality.One of the most clinically significant late effects is the risk of radiation-induced breast cancer, particularly in women who received mediastinal and/or axillary radiotherapy before the age of 30 years [1,2].This risk increases with time since exposure and is influenced by factors including radiation dose, volume, and the use of concurrent chemotherapy, especially alkylating agents that may modulate hormonal exposure [3].Chamberlin et al. have thoroughly conducted a systematic review of breast radiation dose metrics reporting in lymphoma radiotherapy studies published in 2020-2023 [4].Most included studies focused on patients with HL.Across 57 publications, they identified 34 distinct breast dose metrics, with mean breast dose (MBD) being the most commonly reported.Due to the considerable variability in how breast dose was measured and reported, pooling data across studies proved challenging.To address this, the authors propose standardized reporting guidelines to facilitate future large-scale analyses of breast radiation exposure.They emphasize the need to systematically report key factors known to influence breast dose, including whether axillary irradiation was used, given its significant impact on breast tissue exposure.This editorial aims to provide a broader perspective on the risk of late toxicities following radiotherapy for classical HL, with a focus on the impact of contemporary, advanced radiotherapy methods.While the primary focus is on HL, many of the considerations also apply to primary mediastinal B-cell lymphoma and other mediastinal diseases treated with radiotherapy.In addition, the relationship between radiotherapyassociated toxicity and systemic therapy will be explored.Beyond breast cancer, other late effects include cardiovascular disease, hypothyroidism, pulmonary fibrosis, and other secondary malignancies such as lung cancer [5][6][7][8].In limitedstage HL, the radiotherapy is generally preceded by chemotherapy, often two to four cycles of doxorubicin,