Department of Radiation Oncology, Westmead Hospital, University of Sydney, Sydney, Australia.
Int J Radiat Oncol Biol Phys. 2010 Nov 1;78(3):703-9. doi: 10.1016/j.ijrobp.2009.08.011. Epub 2009 Nov 24.
To review the role of radiotherapy (RTx) alone in patients with Merkel cell carcinoma (MCC).
The records of 43 patients with MCC treated with RTx alone between 1993 and 2007 at the Westmead and Royal Brisbane/Mater Hospitals, Australia, were reviewed. Multivariate analysis was performed by use of Cox regression analysis.
The median age was 79 years (range, 48-91 years) in 19 women (44%) and 24 men (56%). All patients were white, and 5 (12%) had immunosuppression. A majority (56%) underwent irradiation at initial diagnosis, with the remainder (44%) treated in the relapse setting. The median duration of follow-up was 39 months. The head and neck comprised the most frequently treated site (47%). The median maximum lesion size was 30 mm (range, 5-130 mm). Relapse developed in 60% of patients, with most being out-of-field relapses. The in-field control rate was 75%. Most out-of-field relapses were to visceral organs. Relapse developed outside the irradiated field in 53% of patients. On multivariate analysis, only nodal status (negative nodes vs. nodes present) was significantly associated with relapse-free survival, with p = 0.005 (hazard ratio, 0.25; 95% confidence interval, 0.96-0.663). Overall survival at 2 and 5 years was 58% and 37%, respectively.
Patients with MCC treated with RTx have a high likelihood of obtaining in-field control. Doses of 50 to 55 Gy in 20 to 25 fractions are recommended. A minority of patients are cured, with many dying of systemic relapse. Lower dose fractionation schedules (e.g., 25 Gy in 5 fractions) may be considered in patients with a very poor performance status.
回顾单纯放射治疗（RTx）在 Merkel 细胞癌（MCC）患者中的作用。
对 1993 年至 2007 年期间在澳大利亚韦斯特米德和皇家布里斯班/梅特医院接受单纯 RTx 治疗的 43 例 MCC 患者的记录进行了回顾性分析。采用 Cox 回归分析进行多变量分析。
19 名女性（44%）和 24 名男性（56%）的中位年龄为 79 岁（范围，48-91 岁）。所有患者均为白人，5 例（12%）存在免疫抑制。大多数（56%）患者在初诊时接受了照射，其余（44%）患者在复发时接受了治疗。中位随访时间为 39 个月。头颈部是最常治疗的部位（47%）。最大病变直径的中位数为 30mm（范围，5-130mm）。60%的患者出现复发，多数为野内复发。野内控制率为 75%。大多数野外复发发生在内脏器官。53%的患者在照射野外出现复发。多变量分析显示，仅淋巴结状态（无淋巴结转移与存在淋巴结转移）与无复发生存率显著相关，p=0.005（风险比，0.25；95%置信区间，0.96-0.663）。2 年和 5 年总生存率分别为 58%和 37%。
接受 RTx 治疗的 MCC 患者获得野内控制的可能性较高。建议使用 50-55Gy 的剂量，20-25 次分割。少数患者被治愈，但许多患者死于全身复发。对于身体状况极差的患者，可能需要考虑更低剂量分割方案（例如，5 次分割 25Gy）。
