Dosimetric comparison of tomotherapy and cyberknife robotic radiosurgery treatment plans for prostate cancer patients

SBRT is a technique that irradiates extracranial lesions being typically smaller than 5 cm within ERBT via high radiation dose. This paper attempts to aim to compare dosimetrically some treatment plans worked out on Tomotherapy and CyberKnife devices by means of using of CT images belong to 10 patients with prostate cancer having low and medium risk level -got a treatment before- in terms of SBRT technique. Prescribed dose of 36.25 Gy in total for 5 fractions is designated to the target volume. As a result of the plans, HI, CI, nCI treatment plans, dosage values corresponding to critical organ volume and MU for per fraction as well as treatment durations have been calculated for the target volume by using DVH. In analysis of the obtained values, the Wilcoxon Signed Ranks Test has been used. Having been done dosimetric comparison of the obtained data for the targeted volumes in the treatment plans worked out on CyberKnife and Tomotherapy, p< 0.05 is occurred for each HI, CI and nCI values. Whilst p< 0.05 is found out in all dosage values correspond to rectum from critical organs (%5, %10, %20, %50) and volume of bladder (5cc, 10cc), dosage values corresponding to femur heads (right-femur, left-femur, 10cc) are calculated as p> 0.05. When analyzed with respect to MU for per fraction and the treatment duration, both of them are also p< 0.05. Statically, CI and nCI parameters on CyberKnife are found out better comparing to Tomotherapy, whereas, HI parameter on Tomotherapy is found better comparing to CyberKnife. As Tomotherapy preserves the bladder and the rectum much better compared to CyberKnife, femur heads give also similar outcomes on the both of devices. When compared of MU for per fraction and the treatment duration, much better results are acquired on Tomotherapy than CyberKnife does.