Maughan R L, Blosser G F, Blosser E B, Yudelev M, Forman J D, Blosser H G, Powers W E
Gershenson Radiation Oncology Center, Harper Hospital, Detroit, MI 48201, USA.
Int J Radiat Oncol Biol Phys. 1996 Jan 15;34(2):411-20. doi: 10.1016/0360-3016(95)02058-6.
To design, construct, and commission a multirod collimator for producing irregularly shaped fields in neutron radiation therapy. To demonstrate the reliability and applicability of this device to routine use with a superconducting cyclotron for neutron therapy.
A multirod collimator has been designed, constructed, and thoroughly tested to investigate its radiological properties; neutron transmission characteristics, beam profiles, and penumbral widths as a function of field size and depth in a phantom, and the spatial resolution of the rod array, have been measured. A wide variety of irregularly shaped fields, used routinely in neutron radiation therapy, have been produced, including fields that incorporate partial transmission blocks. The performance of the collimator has been closely monitored over a period of 20 months to accurately assess reliability.
The multirod collimator has been in routine use for 32 months, and during this time a total of 7025 neutron fields has been treated. For the latter 20 months of this period, detailed performance records show that collimator failure has caused 28.4 h of downtime during the patient treatment day. Only 5.25 h of this downtime was experienced in the last 12 months (0.22% of the available treatment time). The results of collimator attenuation and beam profile measurements show that the radiological properties of the collimator are comparable to those of other collimator systems used for neutron radiation therapy. Isodose measurements in a water phantom show that the spatial resolution of the rods is superior to that of the leaves used in neutron multileaf collimators. The ability of the multirod collimator to produce many irregularly shaped fields commonly encountered in neutron radiation therapy has been demonstrated. Shaped fields for prostate, head and neck, soft tissue sarcomas, lung, thyroid, rectum, bladder, colon, breast, pancreas, and gynecological tumors have been produced. For some prostate cases, the device has been used to produce partial transmission blocks.
A novel multirod collimator has been designed, constructed, and successfully applied in the routine treatment of neutron radiation therapy patients.
设计、构建并调试一种用于中子放射治疗中产生不规则形状射野的多棒准直器。证明该装置与用于中子治疗的超导回旋加速器常规联用的可靠性和适用性。
设计、构建并全面测试了一种多棒准直器以研究其放射学特性；测量了中子传输特性、射野轮廓、半值层宽度与模体中射野大小和深度的函数关系以及棒阵列的空间分辨率。已产生了多种在中子放射治疗中常规使用的不规则形状射野，包括包含部分透射挡块的射野。在20个月的时间里密切监测了准直器的性能以准确评估其可靠性。
多棒准直器已常规使用32个月，在此期间共治疗了7025个中子射野。在此期间的后20个月，详细的性能记录显示准直器故障在患者治疗日导致了28.4小时的停机时间。在过去12个月中仅经历了5.25小时的停机时间（占可用治疗时间的0.22%）。准直器衰减和射野轮廓测量结果表明，该准直器的放射学特性与用于中子放射治疗的其他准直器系统相当。在水模体中的等剂量测量表明，棒的空间分辨率优于中子多叶准直器中使用的叶片。已证明多棒准直器能够产生中子放射治疗中常见的许多不规则形状射野。已产生了用于前列腺、头颈部、软组织肉瘤、肺、甲状腺、直肠、膀胱、结肠、乳腺、胰腺和妇科肿瘤的成形射野。对于一些前列腺病例，该装置已用于产生部分透射挡块。
设计、构建了一种新型多棒准直器，并成功应用于中子放射治疗患者的常规治疗。
