Teunissen F R, Wortel R C, Wessels F J, Claes A, van de Pol S M G, Rasing M J A, Meijer R P, van Melick H H E, de Boer J C J, Verkooijen H M, van der Voort van Zyp J R N
Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, the Netherlands.
Department of Oncological Urology, University Medical Center Utrecht, Utrecht, the Netherlands.
Clin Transl Radiat Oncol. 2021 Nov 14;32:29-34. doi: 10.1016/j.ctro.2021.11.005. eCollection 2022 Jan.
Radiation damage to neural and vascular tissue, such as the neurovascular bundles (NVBs) and internal pudendal arteries (IPAs), during radiotherapy for prostate cancer (PCa) may cause erectile dysfunction. Neurovascular-sparing magnetic resonance-guided adaptive radiotherapy (MRgRT) aims to preserve erectile function after treatment. However, the NVBs and IPAs are not routinely contoured in current radiotherapy practice. Before neurovascular-sparing MRgRT for PCa can be implemented, the interrater agreement of the contouring of the NVBs and IPAs on pre-treatment MRI needs to be assessed.
Four radiation oncologists independently contoured the prostate, NVB, and IPA in an unselected consecutive series of 15 PCa patients, on pre-treatment MRI. Dice similarity coefficients (DSCs) for pairwise interrater agreement of contours were calculated. Additionally, the DCS of a subset of the inferior half of the NVB contours (i.e. approximately prostate midgland to apex level) was calculated.
Median overall interrater DSC for the left and right NVB was 0.60 (IQR: 0.54 - 0.68) and 0.61 (IQR: 0.53 - 0.69) respectively and for the left and right IPA 0.59 (IQR: 0.53 - 0.64) and 0.59 (IQR: 0.52 - 0.64) respectively. Median overall interrater DSC for the inferior half of the left NVB was 0.67 (IQR: 0.58 - 0.74) and 0.67 (IQR: 0.61 - 0.71) for the right NVB.
We found that the interrater agreement for the contouring of the NVB and IPA improved with enhancement of the MRI sequence as well as further training of the raters. The agreement was best in the subset of the inferior half of the NVB, where a good agreement is clinically most relevant for neurovascular-sparing MRgRT for PCa.
前列腺癌（PCa）放疗期间，神经和血管组织（如神经血管束（NVBs）和阴部内动脉（IPAs））受到辐射损伤可能导致勃起功能障碍。保留神经血管的磁共振引导自适应放疗（MRgRT）旨在治疗后保留勃起功能。然而，在当前放疗实践中，NVBs和IPAs并非常规勾画。在实施PCa的保留神经血管MRgRT之前，需要评估治疗前MRI上NVBs和IPAs勾画的评分者间一致性。
四位放射肿瘤学家在15例PCa患者未经选择的连续系列中，根据治疗前MRI独立勾画前列腺、NVB和IPA。计算轮廓的评分者间成对一致性的骰子相似系数（DSCs）。此外，计算NVB轮廓下半部分子集（即大致前列腺中叶至尖部水平）的DCS。
左、右NVB的总体评分者间DSC中位数分别为0.60（IQR：0.54 - 0.68）和0.61（IQR：0.53 - 0.69），左、右IPA分别为0.59（IQR：0.53 - 0.64）和0.59（IQR：0.52 - 0.64）。左NVB下半部分的总体评分者间DSC中位数为0.67（IQR：0.58 - 0.74），右NVB为0.67（IQR：0.61 - 0.71）。
我们发现，随着MRI序列的增强以及评分者的进一步培训，NVB和IPA勾画的评分者间一致性得到改善。在NVB下半部分子集中一致性最佳，在该区域良好的一致性在PCa的保留神经血管MRgRT中临床上最为相关。
