Ultrahypofractionated CyberKnifeTM based stereotactic radiotherapy versus conventional radiotherapy in patients with prostate cancer – acute toxicity evaluation in two phase II prospective studies
Abstract:
Our purpose was to compare the acute toxicity of ultrahypofractionated CyberKnifeTM based stereotactic radiotherapy (SBRT Arm) and conventional radiotherapy (EBRT Arm) in prostate cancer patients. Two-hundred-sixteen men with prostate cancer were enrolled in our prospective studies. One-hundred and nine were irradiated using CyberKnife to total dose of 36,25 Gy in 5 fractions. One-hundred and seven were irradiated conventionally to total dose of 76 Gy in 38 fractions. Mean age of patients was 69. Acute genitourinary (GU) and gastrointestinal (GI) adverse-events were collected. The maximal acute toxicity EORTC/RTOG score was assumed. A total of 41%, 44%, 12% and 3% of patients presented grade 0, 1, 2 and 3 acute genitourinary toxicity in SBRT arm, respectively. A total of 21%, 33%, 43% and 3% of patients demonstrated acute grade 0, 1, 2 and 3 genitourinary toxicity in EBRT arm. A significant difference between number of patients with grade 2 GU toxicity was observed (p-0.000) and between patients without any toxicity (p-0.0017).A significant difference in frequency of acute GI toxicity between both groups was observed, too. 71% vs. 44% had no toxicity (p-0.0001), and 3% vs. 18% (p-0.0004) presented grade 2 GI toxicity in SBRT and EBRT arms respectively.The acute toxicity rates of fractionated stereotactic radiotherapy is lower compared to conventional irradiation.