[Bone metastasis: Efficacy and technical modalities of classical radiotherapy]. / Métastases osseuses : efficacité et modalités de prescription de la radiothérapie classique.

Conventional radiotherapy is a pivotal treatment in the management of bone metastasis. It is indicated primarily for palliative, analgesic, or decompressive purposes and in the prevention of severe bone events such as fractures and spinal cord compressions. It should be performed as early as possible from the onset of symptoms or within 14days following a surgical procedure of decompression or bone stabilization. Except in some cases, a pattern of 8Gy single dose is currently recommended, possibly renewable, by being vigilant on associated treatments which some, like antiangiogenics, must be imperatively suspended.

[Quality control of dose delivered by in vivo dosimetry: can one tolerance be used for all localizations?]. / Contrôle qualité de la dose délivrée par dosimétrie in vivo : un critère de tolérance unique peut-il satisfaire toutes les localisations ?

PURPOSE: In vivo dosimetry measurements are accepted when the difference between measured and calculated dose is under 5%. A statistical analysis has been conducted to determine whether this tolerance matched the clinical practice for the studied localizations: pelvis, thorax, head and neck, breast. MATERIALS AND METHODS: The technical characteristics of the detectors were checked before being used in clinical practice. Then an automatic statistical analysis was implemented using the 2450 in vivo dosimetry measurements obtained during 1 year. MAIN RESULTS: The global average is 1.10%, the standard deviation 2.46% and the percentage of out of level measurements 4.09%. By distinguishing the localizations, the 5% tolerance appeared to be too narrow for the breast localization. DISCUSSION/CONCLUSION: Several investigations were initiated to justify the modification of the tolerance for the breast localization. They highlighted an underestimation of the calculated dose when high beam angles are set: a new correction factor was defined to take account this error. A specific tolerance was also specified for the breast localization.