Helical Tomotherapy in Elderly Prostate Cancer Patients

Background: Helical tomotherapy is a new form of image-guided intensity modulated radiation therapy that may improve local control and decrease radiation toxicity. The aim of this study was to evaluate if high-dose helical tomotherapy is tolerated by patients aged 75 years or older and if the side effects are comparable with those experienced by younger patients. Methods: Between January 2011 and August 2012, patients with prostate cancer who underwent helical tomotherapy without elective pelvic irradiation as definitive aim were reviewed and divided into two age groups: ≥75 years and <75 years. Acute genitourinary (GU) and lower gastrointestinal (GI) toxicities between the two groups were compared. Results: Twenty patients aged 75 years or older and 23 patients younger than 75 years were evaluated. Radiotherapy was administered to a total dose of 76−78 Gy in 38−39 fractions or 70 Gy in 28 fractions. There was no grade 3 or 4 acute toxicity and no grade 2 acute lower GI symptom, but the patients complained of grade 2 acute GU toxicity, 25.0% for the older group and 13.0% for the younger group. There was no significant difference in the rate of acute toxicity between the age groups. Hypofractionation showed a significant association with higher grade 2 acute GU toxicity (p=0.024) with the grade 2 acute GU toxicity having no significant correlation with T-stage, Gleason score, prostate specific antigen level, androgen deprivation therapy, and comorbidities. Conclusion: High-dose helical tomotherapy to the prostate without pelvic irradiation was well tolerated by elderly prostate cancer patients 75 years and older.