MRI prostate contouring is not impaired by the use of a radiotherapy image acquisition set-up. An intra- and inter-observer paired comparative analysis with diagnostic set-up images.

PURPOSE: The use of MRI for radiotherapy planning purposes is growing but image acquisition using radiotherapy set-ups has impaired image quality. Whether differences in image acquisition set-up could modify organ contouring has not been evaluated. Therefore, we aimed to evaluate differences in contouring between paired of image sets that were acquired in the same scanning session using different parameters. MATERIAL AND METHODS: Ten patients underwent RT treatment planning with MRI co-registration. MRI was carried out using two different set-ups during the same session, MRI radiotherapy set-ups and MRI diagnostic set-ups. Prostates and rectums were retrospectively contoured in both image sets by 5 radiation oncologists and 4 radiologists. Intra-observer analysis was carried out comparing organ volumes, the Dice coefficient and hausdorff distance values between two contouring rounds. Inter-observer analysis was carried out by comparing individual contours to a generated STAPLE consensus contour, which is considered the gold standard reference. RESULTS: No significant differences were observed between MRI acquisition set-ups. Significant differences were observed for the dice and hausdorff parameters, comparing individual contours to the STAPLE consensus contour, when analysing diagnostic images between rounds, although raw values were similar. CONCLUSION: Prostate and rectum contours did not differ significantly when using diagnostic or radiotherapy MRI acquisition set-ups.

Radiotherapy is safe in patients with implantable cardiac devices. Analysis of a systematic interrogation follow-up.

INTRODUCTION: The number of patients who have a cardiac implantable electronic device (CIEDs) that undergo a course of radiotherapy is increasing due to the ageing population. The majority of clinical studies only evaluate any CIED malfunction at the end of a course of irradiation or in a case of there being symptoms of possible malfunction. As a result, little data has been collected on CIED status acquired during an active course of irradiation. MATERIAL AND METHODS: We aimed to evaluate the correct functioning of a CIED during a course of radiotherapy. So, a retrospective analysis was made of all patients having CIEDS in a single institution during their course of radiotherapy. All CIEDs were systematically checked before and during the course of radiotherapy according to the risk of device failure and patient dependence. RESULTS: Data was analysed from 56 patients (43 men, 13 women) with a mean age of 78.2 years, of whom 87.5% of the patients carried a pacemaker (PM), the 39% of the patients were PM dependent, and the remaining patients carried an implantable cardioverter-defibrillator (ICD). An observable dose of irradiation was evident in only 10 cases. 69.1% of the CIEDs were checked daily and the remainder were checked weekly. During the radiotherapy course, 82% of the patients did not complain of any cardiological event. The CIED of five patients experienced an increase in the threshold and, in another case, a sudden reduction in the duration of the battery was reported. Another patient with a CIED experienced a cardiac insufficiency episode triggered by a ventricular tachycardia. CONCLUSION: In conclusions, although adverse clinical events from exposure of a CIED to irradiation are rare, they can appear in any group of risk. No dose-dependency was observed on the malfunction of the CIED.