Moran Jean M, Ben-David Merav A, Marsh Robin B, Balter James M, Griffith Kent A, Hayman James A, Pierce Lori J
Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109-0010, USA.
Int J Radiat Oncol Biol Phys. 2009 Sep 1;75(1):294-301. doi: 10.1016/j.ijrobp.2009.03.043. Epub 2009 Jun 18.
The present treatment planning study compared whole breast radiotherapy (WBRT) to accelerated partial breast irradiation (APBI) for different external beam techniques and geometries (e.g., free breathing [FB] and deep inspiration breath hold [DIBH]).
After approval by our institutional review board, a treatment planning study was performed of 10 patients with left-sided Stage 0-I breast cancer enrolled in a Phase I-II study of APBI using intensity-modulated radiotherapy (IMRT). After lumpectomy, patients underwent planning computed tomography scans during FB and using an active breathing control device at DIBH. For the FB geometry, standard WBRT and three-dimensional conformal radiotherapy (3D-CRT) APBI plans were created. For the DIBH geometry with active breathing control, WBRT, 3D-CRT, and IMRT APBI plans were created.
All APBI techniques had excellent planning target volume coverage. The maximal planning target volume dose was reduced from 116% of the prescription dose to 108% with the IMRT(DIBH) APBI plan. The maximal heart dose was >30 Gy for the WBRT techniques, 8.2 Gy for 3D-CRT(FB), and <5.0 Gy for 3D-CRT(DIBH) and IMRT(DIBH) techniques. The mean left anterior descending artery dose was significantly reduced from 11.4 Gy with WBRT(FB) to 4.2 with WBRT(DIBH) and <2.0 Gy with all APBI techniques.
Although planning target volume coverage was acceptable with all techniques, the plans using the DIBH geometry resulted in a marked reduction in the normal tissue dose compared with WBRT planned in the absence of cardiac blocking. Additional study is needed to determine whether these techniques result in clinical benefits.
本治疗计划研究比较了全乳放疗（WBRT）与加速部分乳腺照射（APBI）在不同外照射技术和几何形状（如自由呼吸[FB]和深吸气屏气[DIBH]）下的效果。
经机构审查委员会批准，对10例左侧0-I期乳腺癌患者进行了治疗计划研究，这些患者参加了一项使用调强放疗（IMRT）的APBI I-II期研究。在乳房肿瘤切除术后，患者在自由呼吸时以及使用主动呼吸控制装置进行深吸气屏气时接受计划计算机断层扫描。对于自由呼吸几何形状，创建了标准WBRT和三维适形放疗（3D-CRT）APBI计划。对于使用主动呼吸控制的深吸气屏气几何形状，创建了WBRT、3D-CRT和IMRT APBI计划。
所有APBI技术的计划靶区覆盖均良好。IMRT（DIBH）APBI计划使最大计划靶区剂量从处方剂量的116%降至108%。WBRT技术的最大心脏剂量>30 Gy，3D-CRT（FB）为8.2 Gy，3D-CRT（DIBH）和IMRT（DIBH）技术<5.0 Gy。左前降支动脉平均剂量从WBRT（FB）的11.4 Gy显著降至WBRT（DIBH）的4.2 Gy以及所有APBI技术的<2.0 Gy。
尽管所有技术的计划靶区覆盖均可接受，但与未使用心脏遮挡进行计划的WBRT相比，使用深吸气屏气几何形状的计划导致正常组织剂量显著降低。需要进一步研究以确定这些技术是否能带来临床益处。
