Qi Xin, Gao Xian-Shu, Asaumi Junichi, Zhang Min, Li Hong-Zhen, Ma Ming-Wei, Zhao Bo, Li Fei-Yu, Wang Dian
Department of Radiation Oncology, Peking University First Hospital, Beijing, China.
Department of Oral and Maxillofacial Radiology, Field of Tumor Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Radiat Oncol. 2014 Dec 20;9:288. doi: 10.1186/s13014-014-0288-1.
Intermediate- to-high-risk prostate cancer can locally invade seminal vesicle (SV). It is recommended that anatomic proximal 1-cm to 2-cm SV be included in the clinical target volume (CTV) for definitive radiotherapy based on pathology studies. However, it remains unclear whether the pathology indicated SV extent is included into the CTV defined by current guidelines. The purpose of this study is to compare the volume of proximal SV included in CTV defined by EORTC prostate cancer radiotherapy guideline and RTOG0815 protocol with the actual anatomic volume.
Radiotherapy planning CT images from 114 patients with intermediate- (36.8%) or high-risk (63.2%) prostate cancer were reconstructed with 1-mm-thick sections. The starting and ending points of SV and the cross sections of SV at 1-cm and 2-cm from the starting point were determined using 3D-view. Maximum (D1H, D2H) and minimum (D1L, D2L) vertical distance from these cross sections to the starting point were measured. Then, CTV of proximal SV defined by actual anatomy, EORTC guideline and RTOG0815 protocol were contoured and compared (paired t test).
Median length of D1H, D1L, D2H and D2L was 10.8 mm, 2.1 mm, 17.6 mm and 8.8 mm (95th percentile: 13.5mm, 5.0mm, 21.5mm and 13.5mm, respectively). For intermediate-risk patients, the proximal 1-cm SV CTV defined by EORTC guideline and RTOG0815 protocol inadequately included the anatomic proximal 1-cm SV in 62.3% (71/114) and 71.0% (81/114) cases, respectively. While for high-risk patients, the proximal 2-cm SV CTV defined by EORTC guideline inadequately included the anatomic proximal 2-cm SV in 17.5% (20/114) cases.
SV involvement indicated by pathology studies was not completely included in the CTV defined by current guidelines. Delineation of proximal 1.4 cm and 2.2 cm SV in axial plane may be adequate to include the anatomic proximal 1-cm and 2-cm SV. However, part of SV may be over-contoured.
中高危前列腺癌可局部侵犯精囊（SV）。基于病理学研究，建议在根治性放疗的临床靶区（CTV）中纳入解剖学上近端1厘米至2厘米的精囊。然而，目前尚不清楚病理学所示的精囊范围是否包含在现行指南所定义的CTV中。本研究的目的是比较欧洲癌症研究与治疗组织（EORTC）前列腺癌放疗指南和RTOG0815方案所定义的CTV中近端精囊的体积与实际解剖体积。
对114例中危（36.8%）或高危（63.2%）前列腺癌患者的放疗计划CT图像进行1毫米厚层重建。使用三维视图确定精囊的起点和终点以及距起点1厘米和2厘米处的精囊横截面。测量这些横截面到起点的最大（D1H、D2H）和最小（D1L、D2L）垂直距离。然后，勾勒并比较由实际解剖、EORTC指南和RTOG0815方案定义的近端精囊的CTV（配对t检验）。
D1H、D1L、D2H和D2L的中位数长度分别为10.8毫米、2.1毫米、17.6毫米和8.8毫米（第95百分位数：分别为13.5毫米、5.0毫米、21.5毫米和13.5毫米）。对于中危患者，EORTC指南和RTOG0815方案所定义的近端1厘米精囊CTV分别在62.3%（71/114）和71.0%（81/114）的病例中未充分纳入解剖学上近端1厘米的精囊。而对于高危患者，EORTC指南所定义的近端2厘米精囊CTV在17.5%（20/114）的病例中未充分纳入解剖学上近端2厘米的精囊。
病理学研究所示的精囊受累情况未完全包含在现行指南所定义的CTV中。在轴位平面勾勒近端1.4厘米和2.2厘米的精囊可能足以纳入解剖学上近端1厘米和2厘米的精囊。然而，部分精囊可能被过度勾勒。
