前列腺癌高危患者的 PSMA PET/MRI 与 MRI 临床靶区和淋巴结靶区勾画的变异性。

Variability of radiotherapy volume delineation: PSMA PET/MRI and MRI based clinical target volume and lymph node target volume for high-risk prostate cancer.

机构信息

Department of Radiation Oncology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China.

Department of Nuclear Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China.

出版信息

Cancer Imaging. 2023 Jan 4;23(1):1. doi: 10.1186/s40644-022-00518-7.

DOI:10.1186/s40644-022-00518-7

PMID:36600283

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9811734/

Abstract

PURPOSE

A comparative retrospective study to assess the impact of PSMA Ligand PET/MRI ([68 Ga]-Ga-PSMA-11 and [18F]-F-PSMA-1007 PET/MRI) as a new method of target delineation compared to conventional imaging on whole-pelvis radiotherapy for high-risk prostate cancer (PCa).

PATIENTS AND METHODS

Forty-nine patients with primary high-risk PCa completed the whole-pelvis radiotherapy plan based on PSMA PET/MRI and MRI. The primary endpoint compared the size and overlap of clinical target volume (CTV) and nodal gross tumour volume (GTVn) based on PSMA PET/MRI and MRI. The diagnostic performance of two methods for pelvic lymph node metastasis (PLNM) was evaluated.

RESULTS

In the radiotherapy planning for high-risk PCa patients, there was a significant correlation between MRI-CTV and PET/MRI-CTV (P = 0.005), as well as between MRI-GTVn and PET/MRI-GTVn (P < 0.001). There are non-significant differences in the CTV and GTVn based on MRI and PET/MRI images (P = 0.660, P = 0.650, respectively). The conformity index (CI), lesion coverage factor (LCF) and Dice similarity coefficient (DSC) of CTVs were 0.999, 0.953 and 0.954. The CI, LCF and DSC of GTVns were 0.927, 0.284, and 0.32. Based on pathological lymph node analysis of 463 lymph nodes from 37 patients, the sensitivity, specificity of PET/MRI in the diagnosis of PLNM were 77.78% and 99.76%, respectively, which were higher than those of MRI (P = 0.011). Eight high-risk PCa patients who finished PSMA PET/MRI changed their N or M stage.

CONCLUSION

The CTV delineated based on PET/MRI and MRI differ little. The GTVn delineated based on PET/MRI encompasses metastatic pelvic lymph nodes more accurately than MRI and avoids covering pelvic lymph nodes without metastasis. We emphasize the utility of PET/MRI fusion images in GTVn delineation in whole pelvic radiotherapy for PCa. The use of PSMA PET/MRI aids in the realization of more individual and precise radiotherapy for PCa.

摘要

目的

一项比较回顾性研究，旨在评估 PSMA 配体 PET/MRI（[68Ga]-Ga-PSMA-11 和 [18F]-F-PSMA-1007 PET/MRI）作为一种新的靶区勾画方法，与传统影像学方法相比，在高危前列腺癌（PCa）的全骨盆放疗中的作用。

方法

49 例初治高危 PCa 患者完成了基于 PSMA PET/MRI 和 MRI 的全骨盆放疗计划。主要终点是比较 PSMA PET/MRI 和 MRI 勾画的临床靶区（CTV）和淋巴结大体肿瘤靶区（GTVn）的大小和重叠。评估了两种方法对盆腔淋巴结转移（PLNM）的诊断性能。

结果

在高危 PCa 患者的放疗计划中，MRI-CTV 和 PET/MRI-CTV 之间存在显著相关性（P=0.005），MRI-GTVn 和 PET/MRI-GTVn 之间也存在显著相关性（P<0.001）。MRI 和 PET/MRI 图像上的 CTV 和 GTVn 差异无统计学意义（P=0.660，P=0.650）。CTV 的适形指数（CI）、病变覆盖率因子（LCF）和 Dice 相似系数（DSC）分别为 0.999、0.953 和 0.954。GTVn 的 CI、LCF 和 DSC 分别为 0.927、0.284 和 0.32。基于 37 例患者的 463 个淋巴结的病理分析，PET/MRI 对 PLNM 的诊断灵敏度、特异度分别为 77.78%和 99.76%，高于 MRI（P=0.011）。8 例完成 PSMA PET/MRI 的高危 PCa 患者的 N 或 M 分期发生了变化。

结论

基于 PET/MRI 和 MRI 勾画的 CTV 差异不大。基于 PET/MRI 勾画的 GTVn 比 MRI 更准确地包含了转移性盆腔淋巴结，同时避免了覆盖无转移的盆腔淋巴结。我们强调在 PCa 的全骨盆放疗中，使用 PET/MRI 融合图像进行 GTVn 勾画的实用性。PSMA PET/MRI 的使用有助于实现更个体化和精确的 PCa 放疗。