Accuracy Of Daily Setup Research Articles

Daily Setup Accuracy, Side-effects and Quality of Life During and After Prone Positioned Prostate Radiotherapy.

Exposure of organs at risk with prostate radiotherapy (RT) is lower in the prone position. This study is a prospective evaluation of setup accuracy, side-effects, and quality of life (QOL) during and after prone positioned RT. Image-guided (IG) intensity-modulated (IM) RT was administered in prone position on belly-board to 55 high-risk prostate cancer (PC) patients. Rectum diameters were measured in two areas of the symphysis at the beginning of RT and during it. Side-effects, QOL, and prostate specific symptoms (PSS) were evaluated. Setup accuracy was similar to that reported in the literature. In the upper area of symphysis rectal diameters were significantly changed during treatment, but in the prostate region, no difference was detected. No change was detected in patients' QOL and PSS during treatment, but after RT, they improved. Prone positioned IG-IMRT is feasible with tolerable side-effects for high-risk PC patients. Changes in QOL and PSS are insignificant during RT, while improvement after RT suggests a rapid recovery.

Intensity-modulated radiotherapy (IMRT) with concurrent cisplatin chemotherapy (CT) yields superior therapeutic outcome than conventional techniques with or without chemotherapy in locally advanced nasopharyngeal carcinoma

Results: Five patients with anatomically l\avorable extracranial targets were treated for re-irradiafion or boost phase using the modified GTC stereotactic frame. Diagnosis include nasopharyngeal cancer (3) and sarcoma (2) The depth hehnet measurements for assessing the reproducibili ty and accuracy of daily setup of the modified GTC frame placement resulted in mean deviations between 0 .7-0 .9 mm and mean standard deviations of 0.3 0.5 mm as compared with initial fitting. The relocatibili ty of the frame is well within tolerance (i.e. 1 ram) for daily setup for dose escalation. The accuracy of our geometric isocenter and the radiation isocenter for the linear accelerator used for the SRT program is within less than 1 mm per patient setup. Therefore overall accuracy for using the modified frame for extracranial lesions is about 2 ram. During the target volume identification on MRI or CT scans a 2 mm margin is added based on the reposit ioning and geometrical uncertainty.

Considerations of Fractionated Stereotactic Radiotherapy in Patients with Dentures

Stereotactic radiotherapy (SRT) using the Gill–Thomas–Cosman (GTC) repeat localizer allows for accurate and reproducible daily setup. The formation of a custom dental plate presents a challenge. We present the problems of utilizing this technique in patients with dentures. Twenty-seven patients were referred for fractionated SRT:15 patients had natural teeth and 12 patients had dentures. The comfort and accuracy of daily setup were compared in patients with and without dentures. All patients with natural teeth experienced no discomfort during the treatment and no interruptions were needed. The patients with dentures were categorized into four grades (I–IV), according to the need for medical intervention and necessity for treatment interruption. Two were Grade IV and SRT could not be delivered; alternate treatments were used (one had SRS and one had external RT). Three patients were Grade I, where there was minimal discomfort. Grade II discomfort was encountered in three patients helped by gingival anesthetic cream with no treatment interruption and Grade III was encountered in the remaining four where the treatment was interrupted for variable periods. The mean inaccuracy of daily setup was 2.1 ± 3.0 mm in patients with dentures and 0.48 ± 0.57 mm in patients with natural teeth. The use of the GTC frame is well tolerated and reproducible in patients with natural teeth. Variable degrees of discomfort are noted in patients with dentures and is well correlated to the degree of accuracy and reproducibility. Using other fixation devices, avoiding the oral cavity may be an alternative in patients with Grade III and IV discomfort.