Radiotherapy at the limits of age: evolving fractionation strategies, symptom palliation, and survival in nonagenarians.

Abstract

Advances in radiotherapy (RT) techniques have facilitated the increasing use of hypofractionated treatment schedules, which may be particularly advantageous for elderly patients by reducing treatment burden while maintaining acceptable toxicity. This study aimed to evaluate survival and symptom palliation and to investigate whether different fractionation approaches affected toxicity and clinical outcomes in nonagenarian patients. This single-center retrospective cohort included 199 nonagenarians treated with RT between 2005 and 2023. Fractionation was classified as normofractionated (NF-RT), hypofractionated (HF-RT: >2Gy) and ultra-hypofractionated (UHF-RT: ≥5Gy). Outcomes were symptom control, acute ≥ Grade 2 (G2) toxicity, and overall survival (OS). Median age at RT was 92 years (range 90-101); 42% received curative and 58% palliative RT. Median OS of all patients was 11 months (palliative treatment: 7 months), with 1- and 5-year OS rates of 47% and 11% respectively. Overall, symptom improvement was documented in 73% of patients, with particularly high frequencies of improvement in tumor-related bleeding (95%) and ulceration (80%), pain improved in 65%. Acute ≥ G2 toxicity occurred in 21% (G3, 5%). Generally, UHF-RT and HF-RT had lower odds of ≥ G2 toxicity than NF-RT, however they were treated with lower doses (EQD2) to smaller target volumes. After adjustment for confounding factors, the hazards for all-cause death were only slightly higher for HF-RT and UHF-RT compared to NF-RT. Oligometastatic patients had almost identical survival as those without metastases, patients with breast cancer had a better survival than those with other entities. RT in selected nonagenarians achieved high frequencies of palliation with low severe toxicity. Hypofractionation was well tolerated without clear impact on survival.