Comparison and evaluation of target volume and dose values of critical organs in tomotherapy HI-ART and varian trilogy devices in breast cancer patients in radiotherapy treatment

Adjuvant RT is one of the important components of treatment in patients with breast cancer. In adjuvant breast RT, modern RT techniques (IMRT, HT, etc.) are often preferred to protect organs at risk, especially the heart, especially in left field irradiation. In this study, 2 different modern RT techniques will be compared retrospectively and dosimetrically in patients with left breast cancer. In our study, adjuvant RT of 21 patients with left breast cancer was planned using two separate devices. For the study, two different plans were made in the same patient group with the same contour and dose scheme, HT and Varian Trilogy Device (IMRT). PTV, HI, CI, RAO doses were noted and compared for both plans. SPSS ver 20 (IBM Corporation, Armonk, NY, USA) program was used for statistical analysis and p<0.05 was considered significant. According to our results, the V25 value is median 3688.76 (2385, 79- 7812.3) cc for IMRT and 4718.86 (3154, 5-7620.46) cc for HT. V25 value is significantly higher than HT, however no significant difference was found between the two techniques in V40 dose (p0.095). In addition, lower contralateral lung doses of V5 and V20 were obtained with IMRT. Although significant V25, contralateral lung V5 and V20 dose advantages were obtained with IMRT, the ipsilateral lung V5 dose, heart and LAD mean dose were significantly lower in HT. In this study, it was seen that plans suitable for current dose limitations could be obtained with both techniques. Technique preference should be determined according to the patient. Keywords: Breast cancer, Helical tomotherapy, IMRT.