Fiorentino Alba, Ruggieri Ruggero, Giaj-Levra Niccolò, Sicignano Gianluisa, Di Paola Gioacchino, Naccarato Stefania, Fersino Sergio, Mazzola Rosario, Tebano Umberto, Ricchetti Francesco, Alongi Filippo
Radiation Oncology Division, Radiation Oncology Department, Sacro Cuore Don Calabria Hospital, Cancer Care Center, Via Don Sempeboni 5, 37034, Negrar-Verona, Italy.
Statistic Science Faculty, University of Palermo, Palermo, Italy.
Radiol Med. 2017 Feb;122(2):146-153. doi: 10.1007/s11547-016-0700-z. Epub 2016 Oct 24.
Aim of the present study is to compare three-dimensional conformal RT (3D-CRT) and 4-fields intensity modulated radiation therapy (4f-IMRT) treatment plans, in terms of target dose coverage, integral dose and dose to Organs at risk (OARs) in early breast cancer (BC).
Twenty consecutive BC patients, after lumpectomy, were selected for the present analysis. A total dose of 50 Gy and a simultaneous dose of 60 Gy in 25 fractions was prescribed to Planning Target Volume of the whole breast (PTV) and of the surgical bed, respectively. For each patient, a 3D-CRT plan and a sliding-window 4f-IMRT plan were generated. Conformity and homogeneity indexes (CI, HI) and various organ specific V values were analyzed for PTVs, OARs and normal tissue (NT), respectively.
In terms of HI, 4f-IMRT was superior to 3D-CRT for the PTV (p < 0.0001), and a significant difference for CI was observed in favor of 4f-IMRT (p < 0.0001).In terms of dose to OARs, a superiority of 4f-IMRT was shown. For NT, all parameters are in favor of IMRT, except the V for which the difference was not statistically significant. The average NT-D was 2.7 ± 0.7 for 3D-CRT and 1.8 ± 0.5 for 4f-IMRT (p < 0.0001).
4f-IMRT technique significantly reduced the dose to OARs and NT, with a better target coverage compared to 3D-CRT.
本研究旨在比较三维适形放疗（3D-CRT）和四野调强放疗（4f-IMRT）治疗计划在早期乳腺癌（BC）中靶区剂量覆盖、积分剂量和危及器官（OARs）剂量方面的差异。
选取20例连续的BC患者，均接受了肿块切除术后进行本分析。分别对全乳计划靶区（PTV）和手术床给予50 Gy的总剂量和25次分割的60 Gy同步剂量。为每位患者生成一个3D-CRT计划和一个滑动窗口4f-IMRT计划。分别分析PTV、OARs和正常组织（NT）的适形度和均匀性指数（CI、HI）以及各种器官特异性V值。
在HI方面，4f-IMRT在PTV上优于3D-CRT（p < 0.0001），并且在CI方面观察到有利于4f-IMRT的显著差异（p < 0.0001）。在OARs剂量方面，显示出4f-IMRT的优势。对于NT，除V外所有参数都有利于IMRT，V的差异无统计学意义。3D-CRT的平均NT-D为2.7±0.7，4f-IMRT为1.8±0.5（p < 0.0001）。
与3D-CRT相比，4f-IMRT技术显著降低了OARs和NT的剂量，且靶区覆盖更好。
