迷你辐射疗法治疗（MBRT）：调试和首次临床实施
Minibeam Radiation Therapy Treatment (MBRT): Commissioning and First Clinical Implementation
影响因子:6.50000
分区:医学1区 Top / 肿瘤学2区 核医学2区
发表日期:2024 Dec 01
作者:
Michael P Grams, Chrystian Quintero Mateus, Maryam Mashayekhi, Robert W Mutter, Valentin Djonov, Jennifer M Fazzari, Huaping Xiao, Kelsey M Frechette, Adam J Wentworth, Jonathan M Morris, Brandon Klebel, Jack C Thull, Rachael M Guenzel, David J Schembri Wismayer, Fabrice Lucien, Sean S Park, Scott C Lester
摘要
迷你辐射疗法（MBRT）的特征是在整个肿瘤中递送高“峰值”和低“山谷”剂量的高峰范围。临床前研究长期以来已经表明了这项技术的希望，我们在这里报告了MBRT的第一个临床实施。使用3-，4-，4-，4-，5-，8-和10 cm的直径锥进行了MBRT患者治疗的临床矫正单元。使用钨准直晶仪在中心宽1.1 mm，将180 kVP输出在空间分离为迷你船。使用薄膜和塑料水以达到峰值和山谷剂量，获得了深度剂量（PDD）的百分比测量。在中央轴上测量PDD的0、0.5和1厘米的偏移。在所有锥体和偏移的每个深度上计算峰值与valley的比率。为了减轻患者运动对递送剂量的影响，创建了特定于患者的三维准直仪架。这些符合每位患者的独特解剖结构，并将钨准直仪直接固定在体内。两名患者接受了MBRT治疗；两者都接受了2个分数。峰值PDD随深度逐渐减少。山谷PDD最初随深度略有增加，然后逐渐减少超过2 cm。对于较小的锥体尺寸和偏移，峰值与谷状比率最高。体内薄膜剂量法证实了两名接受MBRT治疗的患者的峰值和山谷剂量的明显描绘，没有剂量模糊。两名患者均迅速改善症状和肿瘤反应。我们报告使用临床矫正器单位进行了调试结果，治疗过程以及用MBRT治疗的前2名患者。虽然证明这种方法的可行性是迈向更广泛翻译的关键第一步，但仍需要进行临床试验以进一步建立安全性和功效。
Abstract
Minibeam radiation therapy (MBRT) is characterized by the delivery of submillimeter-wide regions of high "peak" and low "valley" doses throughout a tumor. Preclinical studies have long shown the promise of this technique, and we report here the first clinical implementation of MBRT.A clinical orthovoltage unit was commissioned for MBRT patient treatments using 3-, 4-, 5-, 8-, and 10-cm diameter cones. The 180 kVp output was spatially separated into minibeams using a tungsten collimator with 0.5 mm wide slits spaced 1.1 mm on center. Percentage depth dose (PDD) measurements were obtained using film dosimetry and plastic water for both peak and valley doses. PDDs were measured on the central axis for offsets of 0, 0.5, and 1 cm. The peak-to-valley ratio was calculated at each depth for all cones and offsets. To mitigate the effects of patient motion on delivered dose, patient-specific 3-dimensional-printed collimator holders were created. These conformed to the unique anatomy of each patient and affixed the tungsten collimator directly to the body. Two patients were treated with MBRT; both received 2 fractions.Peak PDDs decreased gradually with depth. Valley PDDs initially increased slightly with depth, then decreased gradually beyond 2 cm. The peak-to-valley ratios were highest at the surface for smaller cone sizes and offsets. In vivo film dosimetry confirmed a distinct delineation of peak and valley doses in both patients treated with MBRT with no dose blurring. Both patients experienced prompt improvement in symptoms and tumor response.We report commissioning results, treatment processes, and the first 2 patients treated with MBRT using a clinical orthovoltage unit. While demonstrating the feasibility of this approach is a crucial first step toward wider translation, clinical trials are needed to further establish safety and efficacy.