Title: Intensity Modulated Radiation Therapy and Daily Image Guidance Therapy for Localized Prostate Cancer: Clinical Outcome and Toxicity From a Multi-institutional Retrospective Cohort Study
Abstract: Purpose/Objective(s)To evaluate the clinical outcome of both acute and chronic toxicities as well as local control and survival observed in patients treated with intensity modulated radiation therapy (IMRT) with daily image guidance radiation therapy (IGRT) for clinically localized prostate cancer.Materials/MethodsA total of 300 patients with localized prostate cancer treated with IMRT or Rapid Arc therapy, along with daily IGRT via cone-beam CT between September 2006 and January 2010 were retrospectively analyzed from multiple institutions consisting of 3 large community cancer centers. Risk groups (low, intermediate and high) were designated based on National Comprehensive Cancer Network guidelines. Biochemical progression free survival rates (bPFS) were determined based on the American Society for Therapeutic Radiology and Oncology (Phoenix) consensus definition. Acute and chronic toxicities were measured at peak symptoms and at last visit. Toxicity was scored based on Common Terminology Criteria for Adverse Events v4.0.ResultsThe median radiation dose delivered was 81 Gy (range 73.8 Gy - 81 Gy) and 41% of patients received androgen deprivation therapy (mostly in the intermediate and high-risk groups). Median follow-up was 4.7 years (range 4.19 to 7.33 years). The clinical relapse-free survival were 96.6%, 99.2% and 78.6% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). The biochemical progression-free survival rates were 97.5%, 100%, and 82.1% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). The 5-year overall survival rates were 99.2%, 97.6%, and 96.4% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). There were no grade 4 toxicities, and very minimal grade 3 toxicites: 0.67% acute gastrointestinal, 2% acute genitourinary, 2.33% late gastrointestinal, and 0.67% late genitourinary toxicity.ConclusionsThis study represents one of the largest community experiences with intensity modulated radiation therapy along with daily image guidance radiation therapy for prostate cancer. With a median follow-up of 4.7 years, intensity modulated radiation therapy with daily image guidance radiation therapy resulted in outstanding clinical outcomes with low rates of acute and chronic toxicities. Purpose/Objective(s)To evaluate the clinical outcome of both acute and chronic toxicities as well as local control and survival observed in patients treated with intensity modulated radiation therapy (IMRT) with daily image guidance radiation therapy (IGRT) for clinically localized prostate cancer. To evaluate the clinical outcome of both acute and chronic toxicities as well as local control and survival observed in patients treated with intensity modulated radiation therapy (IMRT) with daily image guidance radiation therapy (IGRT) for clinically localized prostate cancer. Materials/MethodsA total of 300 patients with localized prostate cancer treated with IMRT or Rapid Arc therapy, along with daily IGRT via cone-beam CT between September 2006 and January 2010 were retrospectively analyzed from multiple institutions consisting of 3 large community cancer centers. Risk groups (low, intermediate and high) were designated based on National Comprehensive Cancer Network guidelines. Biochemical progression free survival rates (bPFS) were determined based on the American Society for Therapeutic Radiology and Oncology (Phoenix) consensus definition. Acute and chronic toxicities were measured at peak symptoms and at last visit. Toxicity was scored based on Common Terminology Criteria for Adverse Events v4.0. A total of 300 patients with localized prostate cancer treated with IMRT or Rapid Arc therapy, along with daily IGRT via cone-beam CT between September 2006 and January 2010 were retrospectively analyzed from multiple institutions consisting of 3 large community cancer centers. Risk groups (low, intermediate and high) were designated based on National Comprehensive Cancer Network guidelines. Biochemical progression free survival rates (bPFS) were determined based on the American Society for Therapeutic Radiology and Oncology (Phoenix) consensus definition. Acute and chronic toxicities were measured at peak symptoms and at last visit. Toxicity was scored based on Common Terminology Criteria for Adverse Events v4.0. ResultsThe median radiation dose delivered was 81 Gy (range 73.8 Gy - 81 Gy) and 41% of patients received androgen deprivation therapy (mostly in the intermediate and high-risk groups). Median follow-up was 4.7 years (range 4.19 to 7.33 years). The clinical relapse-free survival were 96.6%, 99.2% and 78.6% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). The biochemical progression-free survival rates were 97.5%, 100%, and 82.1% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). The 5-year overall survival rates were 99.2%, 97.6%, and 96.4% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). There were no grade 4 toxicities, and very minimal grade 3 toxicites: 0.67% acute gastrointestinal, 2% acute genitourinary, 2.33% late gastrointestinal, and 0.67% late genitourinary toxicity. The median radiation dose delivered was 81 Gy (range 73.8 Gy - 81 Gy) and 41% of patients received androgen deprivation therapy (mostly in the intermediate and high-risk groups). Median follow-up was 4.7 years (range 4.19 to 7.33 years). The clinical relapse-free survival were 96.6%, 99.2% and 78.6% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). The biochemical progression-free survival rates were 97.5%, 100%, and 82.1% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). The 5-year overall survival rates were 99.2%, 97.6%, and 96.4% for low-risk, intermediate-risk and high-risk groups, respectively (log rank p = 0.05). There were no grade 4 toxicities, and very minimal grade 3 toxicites: 0.67% acute gastrointestinal, 2% acute genitourinary, 2.33% late gastrointestinal, and 0.67% late genitourinary toxicity. ConclusionsThis study represents one of the largest community experiences with intensity modulated radiation therapy along with daily image guidance radiation therapy for prostate cancer. With a median follow-up of 4.7 years, intensity modulated radiation therapy with daily image guidance radiation therapy resulted in outstanding clinical outcomes with low rates of acute and chronic toxicities. This study represents one of the largest community experiences with intensity modulated radiation therapy along with daily image guidance radiation therapy for prostate cancer. With a median follow-up of 4.7 years, intensity modulated radiation therapy with daily image guidance radiation therapy resulted in outstanding clinical outcomes with low rates of acute and chronic toxicities.