Clinical and technical characteristics of intraoperative radiotherapy. Analysis of the ISIORT-Europe database.

BACKGROUND: A joint analysis of clinical data from centres within the European section of the International Society of Intraoperative Radiation Therapy (ISIORT-Europe) was undertaken in order to define the range of intraoperative radiotherapy (IORT) techniques and indications encompassed by its member institutions. MATERIALS AND METHODS: In 2007, the ISIORT-Europe centres were invited to record demographic, clinical and technical data relating to their IORT procedures in a joint online database. Retrospective data entry was possible. RESULTS: The survey encompassed 21 centres and data from 3754 IORT procedures performed between 1992 and 2011. The average annual number of patients treated per institution was 42, with three centres treating more than 100 patients per year. The most frequent tumour was breast cancer with 2395 cases (63.8 %), followed by rectal cancer (598 cases, 15.9 %), sarcoma (221 cases, 5.9 %), prostate cancer (108 cases, 2.9 %) and pancreatic cancer (80 cases, 2.1 %). Clinical details and IORT technical data from these five tumour types are reported. CONCLUSION: This is the first report on a large cohort of patients treated with IORT in Europe. It gives a picture of patient selection methods and treatment modalities, with emphasis on the main tumour types that are typically treated by this technique and may benefit from it.

How the implementation of an in-vivo dosimetry protocol improved the dose delivery accuracy in head and neck radiotherapy.

Doses were measured in-vivo at the entrance using semiconductor detectors for patients with head and neck tumors. Regular measurements started on January 1st and continued till June 30th, 2001. Then the evaluation of the discrepancies between the measured and calculated doses was made, and it resulted in the changes in the protocol of in-vivo dosimetry made effective by February 1st, 2002. The collection of the measurements was censored by January 30th 2003. The number of patients in the two groups was 285 (1st) and 407 (2nd), respectively. The results exhibited the not-Gaussian distribution of the measured doses in both groups. The average number of dose checks per patient increased from 4.9 to 6.0 (1st vs. 2nd group). The mean relative difference between the measured and calculated doses was: -1.5% vs. -0.5%, whereas the standard deviation (1 SD) decreased from 6.1% to 5.6%. The Mann-Whitney U test detected a significant difference between the 1st and the 2nd group (p=0.00000), which justified the conclusion that the changes implemented in the protocol improved dose delivery accuracy and reproducibility of irradiation.