Chicas-Sett Rodolfo, Farga Dolores, Perez-Calatayud Maria J, Celada Francisco, Roldan Susana, Fornes-Ferrer Victoria, Ibanez-Rosello Blanca, Tormo Alejandro, Benlloch Jose M, Perez-Calatayud Jose
Doctoral School, "San Vicente Mártir" Catholic University of Valencia, Valencia, Spain; Department of Radiation Oncology, La Fe Polytechnic and University Hospital, Valencia, Spain; Department of Radiation Oncology, Recoletas Oncology Institute, Campo Grande Hospital, Valladolid, Spain.
Department of Radiation Oncology, La Fe Polytechnic and University Hospital, Valencia, Spain.
Brachytherapy. 2017 May-Jun;16(3):511-517. doi: 10.1016/j.brachy.2017.03.002. Epub 2017 Mar 31.
To determine the significance of dose-volume histogram parameters for predicting late rectal toxicity (LRT) after single-fraction high-dose-rate brachytherapy (HDRBT) boost and external beam radiotherapy (EBRT) in prostate cancer.
Three hundred patients with intermediate- or high-risk prostate cancer were included between August 2010 and March 2015. Treatment comprised a single-fraction HDRBT boost of 15.0 Gy plus EBRT (46.0 Gy delivered in 23 fractions) or an HDRBT boost of 9.5 Gy plus EBRT (60.0 Gy delivered in 30 fractions) if the seminal vesicles were infiltrated using real-time transrectal ultrasound-based planning. LRT was evaluated every 3 months after the end of the combined treatment using the Common Terminology Criteria for Adverse Events, version 4.0. The minimum dose received by the most exposed 0.1 and 2.0 cm volume of the rectum (D0.1 cc/D2cc) was analyzed by estimating the biologically equivalent rectal dose according to the recommendations of the Groupe Européen de Curiethérapie/European Society for Radiotherapy and Oncology and an ordinal regression analysis was performed.
LRT was observed in 62 patients (20.7%) at a median followup of 33 (range, 2-68) months. Twenty patients (6.7%) developed grade 2 and 3 patients (1%) developed grade 3 LRT. A significant association was observed between D2cc and the probability of developing grade 1-3 LRT (p = 0.04).
D2cc is associated with the occurrence of LRT in HDRBT-treated prostate cancer patients. The dose constraints proposed and recommended by experienced HDRBT centers must be investigated to determine the threshold dose through long-term and prospective studies.
确定剂量体积直方图参数在预测前列腺癌单分割高剂量率近距离放疗（HDRBT）增敏联合外照射放疗（EBRT）后晚期直肠毒性（LRT）方面的意义。
纳入2010年8月至2015年3月期间的300例中高危前列腺癌患者。治疗方案为采用基于实时经直肠超声的计划进行15.0 Gy的单分割HDRBT增敏联合EBRT（23次分割给予46.0 Gy），若精囊受侵则采用9.5 Gy的HDRBT增敏联合EBRT（30次分割给予60.0 Gy）。联合治疗结束后每3个月使用《不良事件通用术语标准》第4.0版评估LRT。根据欧洲近距离治疗协作组/欧洲放射肿瘤学会的建议，通过估算生物等效直肠剂量分析直肠最暴露的0.1和2.0 cm体积所接受的最小剂量（D0.1 cc/D2cc），并进行有序回归分析。
在中位随访33（范围2 - 68）个月时，62例患者（20.7%）出现LRT。20例患者（6.7%）发生2级LRT，3例患者（1%）发生3级LRT。观察到D2cc与发生1 - 3级LRT的概率之间存在显著关联（p = 0.04）。
D2cc与接受HDRBT治疗的前列腺癌患者发生LRT相关。必须对经验丰富的HDRBT中心提出和推荐的剂量限制进行研究，通过长期前瞻性研究确定阈值剂量。
