Radiation Therapy in Treating Patients With Prostate Cancer

Adverse events are graded using CTCAE v4.0. Grade refers to the severity of the adverse event (AE). The CTCAE v3.0 assigns Grades 1 through 5 with unique clinical descriptions of severity for each AE based on this general guideline: Grade 1 Mild AE, Grade 2 Moderate AE, Grade 3 Severe AE, Grade 4 Life-threatening or disabling AE, Grade 5 Death related to AE. An acute adverse event is defined as the first occurrence of worst severity of the adverse event ≤30 days after the completion of radiation therapy (RT). The high dose RT arm of Radiation Therapy Oncology Group (RTOG) study RTOG-0126 (NCT00033631) reported 1% of patients experienced grade 3+ GI/GU acute toxicity with no patient experiencing a grade 4 or 5 toxicity. If the lower confidence interval is >1%, then that arm will be further investigated for acceptability. A late adverse event is defined as the first occurrence of worst severity of adverse event >30 days after RT completion. Arms are not compared to each other.

Failure occurs when the PSA is first noted to be 2 ng/mL or more than the current nadir value (PSA > current nadir + 2) post RT completion. Time to PSA failure is defined as time from registration to the date of PSA failure, last known follow-up (censored), or death without PSA failure (competing risk). Rate of PSA failure is estimated by the cumulative incidence method. The protocol specified that one-, two-, and five-year rates would be reported. Arms are not compared to each other.

Disease-free survival duration is time from the date of randomization to the date of documentation of disease progression or until the date of death from any cause (censored). DFS is estimated by the Kaplan-Meier method. The protocol specified that one-, two-, and five-year rates would be reported. Arms are not compared to each other.

Quality-adjusted survival time combines disease-free survival time and quality of life as measured by the EuroQol 5-dimensional (EQ-5D) index score. It is calculated for each patient as the weighted sum of different time episodes and added up to total quality-adjusted life years . The EQ-5D measures health-related quality of life and consists of two parts, a general health visual analog scale and 5 general health questions. The latter questions are transformed into a single index score ranging from 0 (worst health state) to 1 (best health state). Arms are not compared to each other.

The EPIC is a 50-item, validated tool to assess disease-specific aspects of prostate cancer and its therapies and comprises of four summary domains (bowel, urinary, sexual, and hormonal). Response options for each EPIC item form a Likert scale and multi-item scale scores are transformed linearly to a 0-100 scale, with higher scores representing better health related quality of life and a positive change from baseline indicating improvement over time. For this endpoint, in each domain, the actual change score calculated as timepoint score - baseline score will be used as the statistic.

The percentage of patients with a reduction in the EPIC sexual domain score from baseline that exceeds 11 points (baseline - one year > 11). The EPIC is a 50-item, validated tool to assess disease-specific aspects of prostate cancer and its therapies and comprises of four summary domains (bowel, urinary, sexual, and hormonal). Response options for each EPIC item form a Likert scale and multi-item scale scores are transformed linearly to a 0-100 scale, with higher scores representing better health related quality of life. Arms are not compared to each other.

The percentage of patients with a reduction in the EPIC hormonal domain score from baseline that exceeds 3 points (baseline - one year > 3). The EPIC is a 50-item, validated tool to assess disease-specific aspects of prostate cancer and its therapies and comprises of four summary domains (bowel, urinary, sexual, and hormonal). Response options for each EPIC item form a Likert scale and multi-item scale scores are transformed linearly to a 0-100 scale, with higher scores representing better health related quality of life. Arms are not compared to each other.

The EQ-5D is a 2-part self-assessment questionnaire. First part is 5 items (mobility, self care, usual activities, pain/discomfort, anxiety/depression) each with 3 problem levels (1-none, 2-moderate, 3-extreme). Health states are defined by the combination of the leveled responses to the 5 dimensions, generating 243 health states to which unconsciousness and death are added. The 2nd part is a visual analogue scale (VAS) valuing current health state, measured on a 20-cm 10-point interval scale. Worst imaginable health state is scored as 0 at the bottom of the scale, and best imaginable health state is scored as 100 at the top. The 5-item index score is transformed into a utility score between 0 (worst health state) and 1 (best health state). Change from baseline is calculated as score at the timepoint of interested - baseline score. One, 2, and 5 years will be entered when they are available. Arms are not compared.

The Utilization of Sexual Medications/Devices questionaire is designed to assess the use of erectile aids among patients treated for prostate cancer. This instrument is used to complement the sexual symptom domain in the EPIC. The number of subjects responding "Yes" to the following questions are reported: "Do you have a penile prosthesis", "Have you used an medications or devices to aid or improve erections?". Arms are not compared to each other. One, 2, and 5 years will be entered when they are available.