[Optimization of the radiotherapy dosage in vertebral metastases]

The authors describe the radiation therapy treatment planning used in the Department of Radiotherapy of Mauriziano Hospital, Turin, to treat bone metastases from various tumors. The study population consisted of 33 patients with vertebral metastases. Treatment with a 60Co therapy unit was performed following either a conventional or a concentrated schedule. The association of a direct posterior field and a rotational technique with the same center and swing angle varying from 120 degrees and 150 degrees is described. The dose percentage given with the two techniques, the field width and the arching angle variables related to depth and volume of the target are discussed. We present some examples elaborated with a dedicated computer by calculating the integral area dose to the whole body and to the target, towards the best treatment planning for every kind of treatment proposed in two groups of six patients with vertebral and sacral metastases. The technique allows a homogeneous dose distribution to the target, thus reducing the area dose to the whole body, which means good radiotherapeutic results.