Miami Cancer Institute, Baptist Health South Florida, 8900 N Kendall Dr, Miami, FL, 33176, USA.
Radiat Oncol. 2024 Oct 11;19(1):142. doi: 10.1186/s13014-024-02516-4.
PURPOSE/OBJECTIVE(S): Merkel cell carcinoma (MCC) radiation treatment has historically consisted of standard 1.8-2 Gy fractions treated daily over 4-6 weeks. Hypofractionated treatment regimens have demonstrated tumor control and toxicity equivalence to standard fractionation regimens for common cutaneous malignancies such as basal cell and squamous cell carcinomas. Herein we report the outcomes of hypofractionated versus standard fractionation radiotherapy for MCC at our institution.
MATERIALS/METHODS: The study involved a retrospective review of MCC patients treated with radiotherapy. Treatment characteristics and patient outcomes, including acute toxicities, disease recurrence and survival data were collected. The cumulative incidence of local and distant failures was estimated, with death as a competing risk.
A total of 29 treatment courses for 24 patients were included, of which 13 involved standard fractionation with curative intent, 10 involved hypofractionated radiotherapy with curative intent, and 6 involved single fraction (8 Gy) palliative radiation. Half the patients were treated to a head/neck site. A subset of patients treated adjuvantly with curative intent included 8 standard fractionation and 8 hypofractionated radiotherapy patients. No statistically significant differences in local and/or distant failure or overall survival was observed between the patient groups.
Hypofractionated radiotherapy for MCC was associated with similar treatment outcomes relative to standard fractionation. In our limited patient sample, hypofractionated radiation treatment achieved similar results with similar toxicity and fewer treatments. Further analysis of a larger patient population with longer follow up is needed to confirm treatment tolerability and efficacy.
默克尔细胞癌 (MCC) 的放射治疗传统上包括标准的 1.8-2 Gy 分次剂量，每日治疗，持续 4-6 周。对于常见的皮肤恶性肿瘤，如基底细胞癌和鳞状细胞癌，采用低分割治疗方案已显示出与标准分割方案相当的肿瘤控制和毒性。在此，我们报告了我们机构中 MCC 患者接受低分割与标准分割放疗的结果。
本研究回顾性分析了接受放疗的 MCC 患者。收集了治疗特征和患者结局，包括急性毒性、疾病复发和生存数据。估计了局部和远处失败的累积发生率，以死亡为竞争风险。
共纳入 24 例患者的 29 个治疗疗程，其中 13 例为标准分割根治性放疗，10 例为低分割根治性放疗，6 例为单次分割（8 Gy）姑息性放疗。一半的患者接受了头颈部治疗。接受辅助根治性治疗的患者中有一部分包括 8 例标准分割和 8 例低分割放疗患者。患者组之间在局部和/或远处失败或总生存方面无统计学显著差异。
MCC 的低分割放疗与标准分割相比具有相似的治疗结局。在我们有限的患者样本中，低分割放疗具有相似的结果，毒性相似，治疗次数更少。需要进一步分析具有更长随访时间的更大患者人群，以确认治疗耐受性和疗效。
