Oncology Institute of Southern Switzerland, Radiation-Oncology Dept, Bellinzona, Switzerland.
Radiat Oncol. 2010 Feb 19;5:14. doi: 10.1186/1748-717X-5-14.
To report about initial technical and clinical experience in preoperative radiation treatment of rectal cancer with volumetric modulated arcs with the RapidArc (RA) technology.
Twenty-five consecutive patients (pts) were treated with RA. All showed locally advanced rectal adenocarcinoma with stage T2-T4, N0-1. Dose prescription was 44 Gy in 22 fractions (or 45 Gy in 25 fractions). Delivery was performed with single arc with a 6 MV photon beam. Twenty patients were treated preoperatively, five did not receive surgery. Twenty-three patients received concomitant chemotherapy with oral capecitabine. A comparison with a cohort of twenty patients with similar characteristics treated with conformal therapy (3DC) is presented as well.
From a dosimetric point of view, RA improved conformality of doses (CI95% = 1.1 vs. 1.4 for RA and 3DC), presented similar target coverage with lower maximum doses, significant sparing of femurs and significant reduction of integral and mean dose to healthy tissue. From the clinical point of view, surgical reports resulted in a down-staging in 41% of cases. Acute toxicity was limited to Grade 1-2 diarrhoea in 40% and Grade 3 in 8% of RA pts, 45% and 5% of 3DC pts, compatible with known effects of concomitant chemotherapy. RA treatments were performed with an average of 2.0 vs. 3.4 min of 3DC.
RA proved to be a safe, qualitatively advantageous treatment modality for rectal cancer, showing some improved results in dosimetric aspects.
报告使用容积旋转调强放射治疗（RapidArc，RA）技术对直肠癌进行术前放射治疗的初步技术和临床经验。
连续治疗了 25 例患者（pts）。所有患者均表现为局部晚期直肠腺癌，分期为 T2-T4、N0-1。处方剂量为 44 Gy/22 次（或 45 Gy/25 次）。采用 6 MV 光子单弧照射进行治疗。20 例患者接受术前治疗，5 例未接受手术。23 例患者接受卡培他滨口服同步化疗。同时还对 20 例具有相似特征的接受适形治疗（3DC）的患者进行了比较。
从剂量学角度来看，RA 提高了剂量的适形性（CI95%=1.1 对 RA 和 3DC），具有相似的靶区覆盖率，但最大剂量较低，对股骨的保护更好，对健康组织的积分剂量和平均剂量显著降低。从临床角度来看，手术报告显示 41%的病例分期降低。急性毒性仅限于 RA 组的 40%患者发生 1-2 级腹泻和 8%患者发生 3 级腹泻，3DC 组的 45%和 5%患者发生腹泻，与同期化疗的已知作用相兼容。RA 治疗的平均治疗时间为 2.0 分钟，而 3DC 为 3.4 分钟。
RA 被证明是一种安全、质量优越的直肠癌治疗方法，在剂量学方面显示出一些改进的结果。
