Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
Int J Radiat Oncol Biol Phys. 2012 Jan 1;82(1):175-83. doi: 10.1016/j.ijrobp.2010.09.023. Epub 2010 Nov 13.
To demonstrate the feasibility of magnetic resonance lymphography (MRL) -guided delineation of a boost volume and an elective target volume for pelvic lymph node irradiation in patients with prostate cancer. The feasibility of irradiating these volumes with a high-dose boost to the MRL-positive lymph nodes in conjunction with irradiation of the prostate using intensity-modulated radiotherapy (IMRT) was also investigated.
In 4 prostate cancer patients with a high risk of lymph node involvement but no enlarged lymph nodes on CT and/or MRI, MRL detected pathological lymph nodes in the pelvis. These lymph nodes were identified and delineated on a radiotherapy planning CT to create a boost volume. Based on the location of the MRL-positive lymph nodes, the standard elective pelvic target volume was individualized. An IMRT plan with a simultaneous integrated boost (SIB) was created with dose prescriptions of 42 Gy to the pelvic target volume, a boost to 60 Gy to the MRL-positive lymph nodes, and 72 Gy to the prostate.
All MRL-positive lymph nodes could be identified on the planning CT. This information could be used to delineate a boost volume and to individualize the pelvic target volume for elective irradiation. IMRT planning delivered highly acceptable radiotherapy plans with regard to the prescribed dose levels and the dose to the organs at risk (OARs).
MRL can be used to select patients with limited lymph node involvement for pelvic radiotherapy. MRL-guided delineation of a boost volume and an elective pelvic target volume for selective high-dose lymph node irradiation with IMRT is feasible. Whether this approach will result in improved outcome for these patients needs to be investigated in further clinical studies.
展示磁共振淋巴造影（MRL）引导下勾画前列腺癌患者盆腔淋巴结照射的补量和选择性靶区的可行性。还研究了在 MRL 阳性淋巴结上进行高剂量补量照射，并结合强度调制放疗（IMRT）照射前列腺的可行性。
在 4 例有高淋巴结受累风险但 CT 和/或 MRI 无淋巴结肿大的前列腺癌患者中，MRL 检测到盆腔病理性淋巴结。在放疗计划 CT 上识别和勾画这些淋巴结，以创建补量体积。根据 MRL 阳性淋巴结的位置，个体化标准选择性盆腔靶区。创建了一个具有同步整合boost（SIB）的 IMRT 计划，盆腔靶区的剂量处方为 42 Gy，MRL 阳性淋巴结的 boost 剂量为 60 Gy，前列腺的剂量为 72 Gy。
所有 MRL 阳性淋巴结均可在计划 CT 上识别。这些信息可用于勾画补量体积和个体化选择性高剂量淋巴结照射的盆腔靶区。IMRT 计划在规定的剂量水平和危及器官（OARs）的剂量方面提供了高度可接受的放疗计划。
MRL 可用于选择有局限性淋巴结受累的患者进行盆腔放疗。MRL 引导的勾画补量体积和选择性高剂量淋巴结照射的选择性盆腔靶区，结合 IMRT 是可行的。这种方法是否会为这些患者带来更好的结果，需要进一步的临床研究来证实。
