Zukauskaite Ruta, Hansen Christian R, Brink Carsten, Johansen Jørgen, Asmussen Jon T, Grau Cai, Overgaard Jens, Eriksen Jesper G
a Department of Oncology , Odense University Hospital , Denmark.
b Institute of Clinical Research, University of Southern Denmark , Denmark.
Acta Oncol. 2017 Nov;56(11):1554-1561. doi: 10.1080/0284186X.2017.1346384. Epub 2017 Aug 22.
A significant part of patients with head and neck squamous cell carcinoma (HNSCC) develop recurrent disease after curative radiotherapy. We aimed to analyze loco-regional recurrence pattern by identifying possible points of recurrence origin by three different methods in relation to treatment volumes.
A total of 455 patients completed IMRT-based treatment for HNSCC from 2006 to 2012. A total of 159 patients had remaining cancer after IMRT, developed loco-regional recurrence or distant disease during follow-up. Among those, 69 patients with loco-regional recurrences had affirmative CT or PET/CT scan. Possible points of origin (POs) of the recurrences were identified on scans by two independent observers, estimated as center of mass and as maximum surface distance. The recurrence position was analyzed in relation to high-dose treatment volume (CTV1) and 95% of prescription dose.
In total, 104 loco-regional recurrences (54 in T-site and 50 in N-site) were identified in 69 patients. Median time to recurrence for the 69 patients was 10 months. No clinically relevant difference was found between the four POs, with standard deviation between POs in x, y and z axes of 3, 3 and 6 mm. For recurrences inside CTV1, 0-5 mm and 5-10 mm outside CTV1 the standard deviation of dose differences between the POs were 1, 1.4 and 1 Gy, respectively. 56% and 25% of T-site and N-site recurrences were inside CTV1, respectively. Coverage by 95% prescription dose to high-dose treatment volume was achieved in 78% of T-site and 39% of N-site recurrences.
For recurrences identified by possible points of recurrence origin, no significant difference between observer-based or mathematically estimated methods was found. More than half of T-site recurrences were inside high-dose treatment volume, whereas N-site recurrences were mainly outside.
头颈部鳞状细胞癌（HNSCC）患者中有很大一部分在根治性放疗后会出现疾病复发。我们旨在通过三种不同方法确定与治疗靶区相关的可能复发起源点，从而分析局部区域复发模式。
2006年至2012年期间，共有455例患者完成了基于调强放疗（IMRT）的HNSCC治疗。共有159例患者在IMRT后仍有残留癌，在随访期间出现局部区域复发或远处疾病。其中，69例局部区域复发患者的CT或PET/CT扫描结果呈阳性。两名独立观察者通过扫描确定复发的可能起源点（POs），分别估计为质心和最大表面距离。分析复发位置与高剂量治疗靶区（CTV1）及95%处方剂量的关系。
69例患者共发现104处局部区域复发（T区54处，N区50处）。69例患者的复发中位时间为10个月。四个POs之间未发现临床相关差异，POs在x、y和z轴上的标准差分别为3、3和6毫米。对于CTV1内的复发、CTV1外0 - 5毫米和5 - 10毫米处的复发，POs之间剂量差异的标准差分别为1、1.4和1 Gy。T区和N区复发分别有56%和25%在CTV1内。T区78%和N区39%的复发实现了95%处方剂量对高剂量治疗靶区的覆盖。
对于通过可能复发起源点确定的复发，基于观察者的方法和数学估计方法之间未发现显著差异。T区复发超过一半在高剂量治疗靶区内，而N区复发主要在靶区外。
