Dosimetric comparision of surface dose in chest wall irradiations planned with different techniques

From this point of view, it is aimed to compare the calculated dose of the patient in the planning with the values obtained in the planning with different techniques and the values obtained from the measurement. Two different imaging of the Rando phantom in Computed Tomography (CT), with bolus and without bolus, were performed and transferred to the contouring system. Similar to the chest wall, the target volume and critical organs were drawn and transferred to the planning systems. 3BRT, IMRT, VMAT were prepared in the Varian True Beam Millennium linear accelerator therapy device, and Helical treatment plans were prepared in the Accuray Radixact TomoTherapy therapy device.The approved plans were irradiated by placing a MOSFET at the points determined on the rando phantom on the treatment devices, and skin surface dose measurements were taken. The skin surface doses read in the treatment planning system and the skin surface doses read with the mosfet were compared. There is no statistical difference between the mean values of the marked points on the plan and their measurements, independent of the planning technique (p > 0.05). In different treatment techniques studied on the bolus rando phantom, results close to the target dose were obtained in all techniques in planning. In planning without bolus, the skin surface dose has the closest values to the prescription dose in planning made with tomotherapy. There was no significant difference between the mean of the measurement results obtained from the different treatment techniques studied on the randomized phantom without bolus (p=0.075). However, according to the mean and standard deviation values of the measured values, the closest to 5000 cGy dose is the Helical technique. The measurement result obtained from VMAT planning has the lowest dose compared to the prescription dose. Planning algorithms were found to be reliable in predicting skin surface dose. In both cases, the skin surface dose is closest to the prescription dose in the Helical planning technique and the lowest in the VMAT planning technique. This should be taken into account when it is desired to keep the skin surface dose high. Keywords: Bolus, Breast Cancer, MOSFET, Radiotherapy, Rando Phantom,Treatment Planning