Park Jong Min, Park So-Yeon, Choi Chang Heon, Chun Minsoo, Kim Jin Ho, Kim Jung-In
Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.
Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
Oncotarget. 2017 Aug 8;8(53):91174-91184. doi: 10.18632/oncotarget.20039. eCollection 2017 Oct 31.
To investigate the plan quality of tri-Co-60 intensity-modulated radiation therapy (IMRT) with magnetic-resonance image-guided radiation therapy compared with volumetric-modulated arc therapy (VMAT) for prostate cancer. Twenty patients with intermediate-risk prostate cancer, who received radical VMAT were selected. Additional tri-Co-60 IMRT plans were generated for each patient. Both primary and boost plans were generated with tri-Co-60 IMRT and VMAT techniques. The prescription doses of the primary and boost plans were 50.4 Gy and 30.6 Gy, respectively. The primary and boost planning target volumes (PTVs) of the tri-Co-60 IMRT were generated with 3 mm margins from the primary clinical target volume (CTV, prostate + seminal vesicle) and a boost CTV (prostate), respectively. VMAT had a primary planning target volume (primary CTV + 1 cm or 2 cm margins) and a boost PTV (boost CTV + 0.7 cm margins), respectively. For both tri-Co-60 IMRT and VMAT, all the primary and boost plans were generated that 95% of the target volumes would be covered by the 100% of the prescription doses. Sum plans were generated by summation of primary and boost plans. In sum plans, the average values of V70 Gy of the bladder of tri-Co-60 IMRT vs. VMAT were 4.0% ± 3.1% vs. 10.9% ± 6.7%, ( < 0.001). Average values of V70 Gy of the rectum of tri-Co-60 IMRT vs. VMAT were 5.2% ± 1.8% vs. 19.1% ± 4.0% ( < 0.001). The doses of tri-Co-60 IMRT delivered to the bladder and rectum were smaller than those of VMAT while maintaining identical target coverage in both plans.
研究磁共振图像引导放射治疗的三钴 - 60 调强放射治疗（IMRT）与容积调强弧形治疗（VMAT）用于前列腺癌的计划质量。选取 20 例接受根治性 VMAT 的中危前列腺癌患者。为每位患者生成额外的三钴 - 60 IMRT 计划。采用三钴 - 60 IMRT 和 VMAT 技术生成原发计划和推量计划。原发计划和推量计划的处方剂量分别为 50.4 Gy 和 30.6 Gy。三钴 - 60 IMRT 的原发计划靶区（PTV）分别从原发临床靶区（CTV，前列腺 + 精囊）和推量 CTV（前列腺）向外扩 3 mm 生成。VMAT 则分别有原发计划靶区（原发 CTV + 1 cm 或 2 cm 边界）和推量 PTV（推量 CTV + 0.7 cm 边界）。对于三钴 - 60 IMRT 和 VMAT，生成的所有原发计划和推量计划均使 95% 的靶区体积接受 100% 的处方剂量。通过将原发计划和推量计划相加生成总计划。在总计划中，三钴 - 60 IMRT 与 VMAT 相比，膀胱 V70 Gy 的平均值分别为 4.0% ± 3.1% 与 10.9% ± 6.7%，（< 0.001）。三钴 - 60 IMRT 与 VMAT 相比，直肠 V70 Gy 的平均值分别为 5.2% ± 1.8% 与 19.1% ± 4.0%（< 0.001）。在两个计划保持相同靶区覆盖的情况下，三钴 - 60 IMRT 给予膀胱和直肠的剂量低于 VMAT。
