Colombo F, Benedetti A, Pozza F, Avanzo R C, Marchetti C, Chierego G, Zanardo A
Neurosurgery. 1985 Feb;16(2):154-60. doi: 10.1227/00006123-198502000-00005.
Stereotactic radiotherapy has two advantages: (a) the possibility of giving high radiation doses to small but spatially well-defined target volumes and (b) the presence of a stepped dose gradient between the target volume and the surrounding healthy tissues. To utilize these advantages, the authors built a new stereotactic head frame by which the intracranial target is fixed to the rotational isocenter of a 4-MV linear accelerator. The collimator openings are selected according to the volume and the three-dimensional configuration of the target, and the radiation dose is based on the radiosensitivity of the lesion. After the patient is fixed to the frame, the radiation source and the patient are rotated so that the target is irradiated through infinite portals distributed over the convexity of the skull. It is thereby possible to obtain very high radiation doses centered into the target with a stepped dose gradient. The preliminary radiodosimetric tests and the operative technique are described. The advantages of this technique compared to interstitial radiotherapy and Leksell's radiosurgery are emphasized. This noninvasive procedure has been used to treat a series of intracranial tumors.
（a）能够对小而空间位置明确的靶体积给予高辐射剂量；（b）在靶体积与周围健康组织之间存在阶梯式剂量梯度。为利用这些优点，作者构建了一种新的立体定向头架，通过该头架可将颅内靶区固定于4兆伏直线加速器的旋转等中心。根据靶区的体积和三维构型选择准直器开口，辐射剂量则基于病变的放射敏感性。患者固定于头架后，旋转辐射源和患者，以便通过分布于颅骨凸面的无数射野对靶区进行照射。由此能够以阶梯式剂量梯度在靶区中心获得非常高的辐射剂量。文中描述了初步的放射剂量学测试和手术技术。强调了该技术与间质放疗和Leksell立体定向放射外科相比的优点。这种非侵入性 procedure 已用于治疗一系列颅内肿瘤。 （注：原文中“operative technique”直译为“手术技术”，但结合上下文这里的“procedure”可能更合适，可根据实际情况调整。）
