[Experience feed back committee in radiotherapy (CREx): a compulsory tool for security management evaluation at two years]. / La cellule de retour d'expérience (CREx) en radiothérapie: un outil indispensable au management de la sécurité. Une évaluation après deux ans d'activité au centre Oscar-Lambret.

After working on treatment organisation in radiotherapy (bonne pratiques organisationnelles en radiothérapie - action pilote MEAH 2003), the development of a security policy has become crucial. With the help of Air France Consulting and the MEAH, three cancer centers in Angers, Lille and Villejuif worked together on the implantation of experience feed back committees (CREx) dedicated to the registration, analysis and correction of precursor events. After two years, we report the centre Oscar-Lambret experience in Lille and try to get the recommendations for generalisation of the process. This seems now to be compulsory for security management in oncology.

[In vivo dosimetry and radiation therapy of breast cancer]. / Dosimétrie in vivo et radiothérapie des cancers du sein.

INTRODUCTION: Verification of absorbed dose in target volume is a key factor for quality assurance in radiotherapy. In vivo measurements allow evaluation of the variations in dose with time and variations between measured doses and calculated doses by TPS. The aim of this work were to evaluate reproducibility of patient positioning and to compare calculated doses by 2 different TPS. PATIENTS AND METHODS: Twenty patients were divided in 2 groups according to the thickness of their breast (mean SSD = 92.9 cm). In vivo measurement was performed within the first two sessions. RESULTS: Reproducibility of SSD evaluation was made on 12 beams between 2 fractions. With a tolerance margin of 0.5 cm, positioning errors were present in 33% (4/12). The 2 TPS were in agreement in 75% (30/40). CONCLUSION: In vivo dosimetry can be a very interesting tool to assess patients positioning variations and TPS dose calculation.