Departments of Diagnostic Radiology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
Radiographics. 2013 May;33(3):741-61. doi: 10.1148/rg.333125041.
Radiation therapy (RT) is one of the principal treatment modalities for localized or locally advanced prostate cancer. The two major forms of RT for prostate cancer are external-beam RT (EBRT) with a photon or proton beam and brachytherapy. With modern conformal techniques for EBRT (three-dimensional conformal RT, intensity-modulated RT, and image-guided RT) and advanced computer-based planning systems for brachytherapy, the dose can be more precisely delivered to the prostate while reducing unnecessary radiation to normal tissue. The dominant intraprostatic tumor can be targeted with a higher dose, so-called dose painting. Magnetic resonance (MR) imaging plays a pivotal role in pretreatment assessment of prostate cancer. Multiparametric MR imaging, a combination of anatomic and functional MR imaging techniques (diffusion-weighted imaging, dynamic contrast material-enhanced imaging, and MR spectroscopy), significantly improves the accuracy of tumor localization and local staging. For pretreatment planning, anatomic MR imaging provides highly accurate local staging information, particularly about extraprostatic extension and seminal vesicle invasion. The dominant intraprostatic tumor and local recurrence in the prostatectomy bed can be better localized with multiparametric MR imaging for dose painting. MR imaging allows excellent delineation of the contours of the prostate and surrounding structures. It can also be used in early posttreatment evaluation after brachytherapy.
放射治疗（RT）是局部或局部晚期前列腺癌的主要治疗方法之一。前列腺癌的两种主要 RT 形式是外束 RT（EBRT），使用光子或质子束和近距离放射治疗。通过 EBRT 的现代适形技术（三维适形 RT、调强 RT 和图像引导 RT）和先进的基于计算机的近距离放射治疗计划系统，可以更精确地将剂量输送到前列腺，同时减少对正常组织的不必要辐射。可以用更高的剂量靶向主导的前列腺内肿瘤，即所谓的剂量描绘。磁共振成像（MR）在前列腺癌的术前评估中起着关键作用。多参数 MR 成像，是解剖和功能 MR 成像技术（扩散加权成像、动态对比增强成像和 MR 波谱）的结合，显著提高了肿瘤定位和局部分期的准确性。对于术前计划，解剖学 MR 成像提供了高度准确的局部分期信息，特别是关于前列腺外扩展和精囊侵犯。多参数 MR 成像可更好地定位前列腺切除术床内的主导性前列腺内肿瘤和局部复发，用于剂量描绘。MR 成像可以极好地描绘前列腺和周围结构的轮廓。它也可以用于近距离放射治疗后的早期治疗后评估。
