微束放射治疗 (MBRT) 的特点是在整个肿瘤中传递亚毫米宽的高“峰”剂量和低“谷”剂量。临床前研究早已显示了这项技术的前景，我们在这里报告了 MBRT 的首次临床实施。临床正电压装置被委托使用 3、4、5、8 和 10 厘米直径的锥体进行 MBRT 患者治疗。使用钨准直器将 180 kVp 输出在空间上分成小光束，该准直器具有 0.5 毫米宽的狭缝，中心间距为 1.1 毫米。使用胶片剂量测定法和塑料水获得峰剂量和谷剂量的百分比深度剂量 (PDD) 测量。 PDD 在中心轴上测量，偏移量为 0、0.5 和 1 厘米。计算所有锥体和偏移量在每个深度的峰谷比 (PVR)。为了减轻患者运动对输送剂量的影响，创建了患者专用的 3D 打印准直器支架。这些符合每位患者独特的解剖结构，并将钨准直器直接固定在身体上。两名患者接受 MBRT 治疗，均接受 2 次分次。峰值 PDD 随着深度逐渐降低。谷PDD最初随深度略有增加，然后在2厘米以上逐渐减少。对于较小的锥体尺寸和偏移量，PVR 在表面最高。体内胶片剂量测定证实了两名接受 MBRT 治疗的患者的峰值和谷值剂量的明显界限，没有剂量模糊。两名患者的症状和肿瘤反应均得到迅速改善。我们报告调试结果、治疗过程以及使用临床正电压装置接受 MBRT 治疗的前两名患者。虽然证明这种方法的可行性是迈向更广泛转化的关键第一步，但还需要进行临床试验来进一步确定安全性和有效性。版权所有 © 2024。由 Elsevier Inc. 出版。

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 central axis for offsets of 0, 0.5, and 1 cm. The peak-to-valley ratio (PVR) was calculated at each depth for all cones and offsets. To mitigate the effects of patient motion on delivered dose, patient-specific 3D 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. PVRs were highest at the surface for smaller cone sizes and offsets. In vivo film dosimetry confirmed a distinct delineation of peak and valley doses on 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 two patients treated with MBRT using a clinical orthovoltage unit. While demonstrating feasibility of this approach is a crucial first step toward wider translation, clinical trials are needed to further establish safety and efficacy.Copyright © 2024. Published by Elsevier Inc.