Herein András, Stelczer Gábor, Pesznyák Csilla, Fröhlich Georgina, Smanykó Viktor, Mészáros Norbert, Polgár Csaba, Takácsi-Nagy Zoltán, Major Tibor
National Institute of Oncology, Centre of Radiotherapy, Budapest, Hungary.
Budapest University of Technology and Economic, Institute of Nuclear Techniques, Budapest, Hungary.
Rep Pract Oncol Radiother. 2022 Mar 22;27(1):152-160. doi: 10.5603/RPOR.a2022.0011. eCollection 2022.
The purpose of the study was to dosimetrically compare multicatheter interstitial brachytherapy (MIBT) and stereotactic radiotherapy with CyberKnife (CK) for accelerated partial breast irradiation with special focus on dose to organs at risk (OARs).
Treatment plans of thirty-one patients treated with MIBT were selected and additional CK plans were created on the same CT images. The OARs included ipsilateral non-target and contralateral breast, ipsilateral and contralateral lung, skin, ribs, and heart for left sided cases. The fractionation was identical (4 × 6.25 Gy). Dose-volume parameters were calculated for both techniques and compared.
The D90 of the PTV for MIBT and CK were similar (102.4% . 103.6%, p 0.0654), but in COIN the MIBT achieved lower value (0.75 . 0.91, p < 0.001). Regarding the V100 parameter of non-target breast CK performed slightly better than MIBT (V100: 1.1% . 1.6%), but for V90, V50 and V25 MIBT resulted in less dose. Every examined parameter of ipsilateral lung, skin, ribs and contralateral lung was significantly smaller for MIBT than for CK. Protection of the heart was slightly better with MIBT, but only the difference of D2cm was statistically significant (17.3% . 20.4%, p 0.0311). There were no significant differences among the dose-volume parameters of the contralateral breast.
The target volume can be properly irradiated by both techniques with high conformity and similar dose to the OARs. MIBT provides more advantageous plans than CK, except for dose conformity and the dosimetry of the heart and contralateral breast. More studies are needed to analyze whether these dosimetrical findings have clinical significance.
本研究的目的是对多导管组织间近距离放射治疗（MIBT）和射波刀（CK）立体定向放射治疗在加速部分乳腺照射方面进行剂量学比较，特别关注危及器官（OARs）的剂量。
选取31例接受MIBT治疗的患者的治疗计划，并在相同的CT图像上创建额外的CK计划。对于左侧病例，OARs包括同侧非靶区和对侧乳腺、同侧和对侧肺、皮肤、肋骨和心脏。分割方式相同（4×6.25 Gy）。计算两种技术的剂量体积参数并进行比较。
MIBT和CK的计划靶体积（PTV）的D90相似（102.4%对103.6%，p = 0.0654），但在一致性指数（COIN）方面，MIBT的值较低（0.75对0.91，p < 0.001）。关于非靶区乳腺的V100参数，CK略优于MIBT（V100：1.1%对1.6%），但对于V90、V50和V25，MIBT导致的剂量更低。MIBT的同侧肺、皮肤、肋骨和对侧肺的每个检查参数均显著低于CK。MIBT对心脏的保护略好，但仅D2cm的差异具有统计学意义（17.3%对20.4%，p = 0.0311）。对侧乳腺的剂量体积参数之间无显著差异。
两种技术均可对靶体积进行适形照射，对OARs的剂量相似。除了剂量适形性以及心脏和对侧乳腺的剂量学外，MIBT提供的计划比CK更具优势。需要更多研究来分析这些剂量学结果是否具有临床意义。
