Performance analysis of a film dosimetric quality assurance procedure for IMRT with regard to the employment of quantitative evaluation methods.

A system for dosimetric verification of intensity-modulated radiotherapy (IMRT) treatment plans using absolute calibrated radiographic films is presented. At our institution this verification procedure is performed for all IMRT treatment plans prior to patient irradiation. Therefore clinical treatment plans are transferred to a phantom and recalculated.

Introducing a system for automated control of rotation axes, collimator and laser adjustment for a medical linear accelerator.

Mechanical stability and precise adjustment of rotation axes, collimator and room lasers are essential for the success of radiotherapy and particularly stereotactic radiosurgery with a linear accelerator. Quality assurance procedures, at present mainly based on visual tests and radiographic film evaluations, should desirably be little time consuming and highly accurate. We present a method based on segmentation and analysis of digital images acquired with an electronic portal imaging device (EPID) that meets these objectives.

Radiotherapy for invasive thymoma and thymic carcinoma. Clinicopathological review.

Purpose: This study reports clinicopathological features and outcome of thymic tumors. Twenty-seven patients with invasive thymoma and 6 patients with thymic carcinoma who had received radiotherapy either primary or postoperatively were analyzed retrospectively.

Patients And Methods: All 33 patients were irradiated with a mean dose of 50 Gy after complete resection (16 patients), partial resection (9 patients) or biopsy (8 patients).

A quality assurance program in stereotactic radiosurgery using the Gamma Knife unit.

Because of the large single-fraction dose in stereotactic radiosurgery it is important to guarantee a high geometric and dosimetric accuracy. The paper represent the quality assurance program for the Gamma Knife unit at the University Clinic of Neurosurgery in Graz. The program includes the following procedures: timer control, mechanical radiation isocenter coincidence, trunnion centricity, helmet microswitches test, radiation output and relative helmet factors, dose profile verification, safety interlocks checks and software quality assurance.

Prognostic factors in patients with carcinoma of the uterine cervix treated with external beam irradiation and IR-192 high-dose-rate brachytherapy.

Purpose: Prognostic factors in cancer of the cervix for patients treated with external beam irradiation (EBR) and low-dose-rate (LDR) brachytherapy have been characterized. However, despite the increasing use of high-dose-rate (HDR) intracavitary placements (ICP), few studies with adequate follow-up have analyzed prognostic factors. This study investigates pretreatment and treatment factors for their correlation with treatment outcome after EBR and HDR-ICP.