Shankar Ravi A, Nibhanupudy J Rao, Sridhar Rajagopalan, Ashton Cori, Goldson Alfred L
Department of Radiation Oncology, Howard University Hospital, Washington DC 20060, USA.
J Natl Med Assoc. 2003 Apr;95(4):286-95.
Breast reconstruction is an option for women undergoing modified radical mastectomy due to a diagnosis of breast cancer. In certain patients, breast reconstruction is performed by insertion of a temporary tissue expander prior to the placement of permanent breast implants. Some of these patients, following mastectomy, may require chest wall irradiation to prevent loco regional relapse. The compatibility of radiation and tissue expanders placed in the chest wall is of major concern to the radiation oncologist. Clinically undetectable changes can occur in the tissue expander during the course of radiation therapy. This can lead to radiation treatment set-up changes, variation in tissue expansion resulting in unwanted cosmesis, and deviation from the prescribed radiation dose leading to over and/or under dosing of tumor burden. At Howard University hospital, a CT scan was utilized to evaluate the status of the temporary tissue expander during radiation treatment to enable us to prevent radiation treatment related complications resulting from dosimetric discrepancies. CT images of the tissue expander were obtained through the course of treatment. To avoid a 'geographic miss' the amount of fluid injected into the tissue expander was kept constant following patient's satisfaction with the size of the breast mound. The CT scans allowed better visualization of the prosthesis and its relation to the surrounding tumor bed. This technique ensured that anatomical changes occurring during radiation treatment, if any, were minimized. Repeated dosimetry evaluations showed no changes to the prescribed dose distribution. A CT of the reconstructed breast provides an important quality control. Further studies with greater number of patients are required for confirming this impact on radiation treatment.
对于因乳腺癌而接受改良根治性乳房切除术的女性来说,乳房重建是一种选择。在某些患者中,在植入永久性乳房植入物之前,会先插入一个临时组织扩张器来进行乳房重建。这些患者中的一些人在乳房切除术后可能需要进行胸壁放疗以预防局部区域复发。放疗肿瘤学家主要关注放疗与置于胸壁的组织扩张器的兼容性。在放射治疗过程中,组织扩张器可能会出现临床无法检测到的变化。这可能导致放疗设置改变、组织扩张变化导致不理想的美容效果,以及偏离规定的放射剂量,从而导致肿瘤负荷剂量过高和/或过低。在霍华德大学医院,利用CT扫描来评估放射治疗期间临时组织扩张器的状态,以使我们能够预防因剂量差异导致的放疗相关并发症。在治疗过程中获取了组织扩张器的CT图像。为避免“地理遗漏”,在患者对乳房隆起大小满意后,注入组织扩张器中的液体量保持恒定。CT扫描能更好地显示假体及其与周围肿瘤床的关系。这项技术确保了放射治疗期间发生的解剖学变化(如果有的话)被最小化。重复的剂量测定评估显示规定的剂量分布没有变化。重建乳房的CT提供了重要的质量控制。需要对更多患者进行进一步研究以证实这对放射治疗的影响。