| Abstract [eng] |
Spine metastases are common and complex cancer, which induce severe pain and neurological problems, such as sensitivity reduction, paralysis, etc. The primary lung localisation stereotactic radiotherapy was performed, using two different fractionation schedules (48Gy (6Gy/8 fr.) and 60 Gy (7.5 Gy/ 8 fr.)). Two additional plans for the recurrent disease treatment were planned (planning target volume (PTV)+spinal cord (SC) and PTV-SC), using volumetric modulated arc therapy technique. PTV+SC means, that the spinal cord was involved in PTV volume, while PTV-SC means, that the spinal cord was contoured separately as an organ at risk. These plans were evaluated, using 5 different dose fractionation schedules (30 Gy (3 Gy/10fr.); 20 Gy (4 Gy/5 fr.); 20 Gy (5 Gy/4 Fr); 8 Gy (8 Gy/1 fr.) and 7 Gy (7 Gy/1 fr.)). These two cases for the recurrent disease (spine metastasis) irradiation were planned, trying to minimize side effects for SC. Treatment planning results were evaluated dosimetrically (DHI, DCI, DGI) and biologically (BED, EQD). It was found, that 4 different fractionation schedules were in a tolerance level, while the other cases differed from the low risk of myelopathy up to the high risk of myelopathy. It means that the fractionation schedule is an important step for recurrent disease irradiation in the near vicinity of the primary tumour. Also, it is important to pay attention to the interval between two treatment courses. |
