[en] Purpose: To review all the available radiotherapy (RT) literature on localized prostate cancer treatment where serum prostate-specific antigen (PSA) levels were used to both stratify patients and evaluate outcome and determine if any conclusions can be reached regarding an optimal radiotherapeutic management for this disease. Methods and Materials: A MEDLINE search was conducted to obtain all articles in English on prostate cancer treatment employing RT from 1986-1997. Studies were considered eligible for review only if they met all the following criteria: 1) pretreatment PSA values were recorded and grouped for subsequent evaluation, 2) posttreatment PSA values were continuously monitored, 3) definitions of biochemical control were stated, and 4) the median follow-up was given. Results: Of the 246 articles identified, only 20 met the inclusion criteria; 4 using conformal external beam RT, 8 using conventional external beam RT, and 8 using interstitial brachytherapy (4 using a permanent implant alone, 3 combining external beam RT with a permanent implant, and 1 combining a conformal temporary interstitial implant boost with external beam RT). No studies using neutrons (with or without external beam RT) or androgen deprivation (combined with external beam RT) were identified where patients were stratified by pretreatment PSA levels. Results for all therapies were extremely variable with the 3-5-year rates of biochemical control for patients with pretreatment PSA levels ≤4 ng/ml ranging from 48 to 100%, for PSA levels >4 and ≤10 ng/ml ranging from 44 to 90%, for PSA levels >10 and ≤20 ng/ml ranging from 27 to 89%, and for PSA levels >20 ranging from 14 to 89%. The median Gleason score, T-stage, definition of biochemical control, and follow-up were substantially different from series to series. No RT option consistently produced superior results. Conclusions: When data are reviewed from studies using serum PSA levels to stratify patients and to evaluate treatment outcome, no consistently superior RT technique was identified. These data suggest that standard definitions of disease stage (combining clinical, pathologic, and biochemical criteria) and a common definition of biochemical cure (as developed by the American Society for Therapeutic Radiology and Oncology Consensus Panel) need to be adopted to evaluate treatment efficacy and advise patients on the most appropriate radiotherapeutic option for their disease

[en] Purpose: We reviewed our institution's experience treating patients with external beam irradiation (RT) to determine if the ASTRO Consensus Panel definition of biochemical failure (BF) following radiation therapy correlates with clinical distant metastases free survival (DMFS), disease-free survival (DFS), cause-specific survival (CSS), and local control (LC). Methods and Materials: Between 1/1/87 and 12/31/92, 568 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital (median total dose 66.6 Gy; range: 60-70.4 Gy). Biochemical failure was defined as three consecutive increases in post-treatment prostate specific antigen (PSA) after achieving a nadir. Biochemical failure was recorded as the time midway between the nadir and the first rising PSA. Five-year actuarial rates of clinical DMFS, DFS, CSS, and LC were calculated for patients who were biochemically controlled (BC) versus those who failed biochemically. Median follow-up was 56 months (range: 24-118 months). Results: Five-year actuarial rates of DMFS, DFS, CSS, and LC were significantly greater in patients who were biochemically controlled versus those who were not (p < 0.001). In patients who were BC, the 5-year actuarial rates of DMFS, DFS, CSS, and LC were 99%, 99%, 98%, and 99% respectively. For patients who failed biochemically, the 5-year actuarial rates of DMFS, DFS, CSS, and LC were 74%, 64%, 89%, and 86% respectively. When stratifying by pretreatment PSA, Gleason score, and T stage these differences remained significant for DMFS, DFS, and CSS. The Cox proportional hazards model demonstrated that BC was the single most important predictor of clinical outcome for DMFS, DFS, CSS, and LC. Pretreatment PSA and Gleason score were also independent predictors of outcome for DMFS and DFS. Conclusions: The ASTRO Consensus Panel definition of BF following radiation therapy correlates well with clinical DMFS, DFS, and CSS. These findings suggest that the Consensus Panel definition may be a surrogate for clinical progression and survival and should be considered a valid endpoint for separating successful versus unsuccessful treatment. Additional studies with longer follow-up will be needed to corroborate these findings

[en] Purpose: We reviewed our institution's experience in treating patients with clinically localized prostate cancer with external beam irradiation (RT) to determine if previously analyzed clinical and treatment related prognostic factors affected outcome when biochemical control was used as an end-point to evaluate results. Materials and methods: Between 1 January 1987 and 31 December 1991, 470 patients with clinically localized prostate cancer were treated with external beam RT using localized prostate fields at William Beaumont Hospital. Biochemical control was defined as PSA nadir ≤1.5 ng/ml within 1 year of treatment. After achieving nadir, if two consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase. Prognostic factors, including the total number of days in treatment, the method of diagnosis, a history of any pretreatment transurethral resection of the prostate (TURP) and the type of boost were analyzed. Results: Median follow-up was 48 months. No statistically significant difference in rates of biochemical control were noted for treatment time, overall time (date of biopsy to completion of RT), history of any pretreatment TURP, history of diagnosis by TURP, or boost techniques. Patients diagnosed by TURP had a significant improvement in the overall rate of biochemical control (P < 0.03) compared to transrectal/transperineal biopsy. The 5-year actuarial rates were 58 versus 39%, respectively. This improvement was not evident when pretreatment PSA, T stage, or Gleason score were controlled for. On multivariate analysis, no variable was associated with outcome. When analysis was limited to a more favorable group of patients (T1/T2 tumors, pretreatment PSA ≤20 ng/ml and Gleason score <7), none of these variables were significantly predictive of biochemical control when controlling for pretreatment PSA, T stage and Gleason score. Conclusions: No significant effect of treatment time, overall time, pretreatment TURP, or boost technique was noted on outcome in patients treated with conventional external beam irradiation when biochemical control was used as the end-point to evaluate results

[en] Purpose/Objective: Indications for post-prostatectomy radiation therapy are not well defined. We reviewed our experience treating post-prostatectomy patients with external beam irradiation to assess clinical and pathologic factors predictive of biochemical control. Materials and Methods: Between 1/87 and 3/93, 61 patients received post-operative tumor bed irradiation with a median dose of 59.4 Gy (50.4 - 68 Gy). Median follow-up was 4.1 years (7.6 months - 8.3 years) from irradiation. Patients were treated for the following reasons: 1) adjuvantly, within 6 months of surgery for extracapsular extension, seminal vesicle involvement, or positive surgical margins (n=38); 2) persistently elevated PSA post-operatively (n=2); 3) rising PSA >6 months after surgery (n=9); and 4) biopsy proven local recurrence (n=12). No patients had known nodal or metastatic disease. All patients had post-radiation PSA data available. Biochemical control was the endpoint studied using Kaplan-Meier life table analysis. Biochemical control was defined as the ability to maintain an undetectable PSA (< 0.4 ng/ml) after irradiation. If the PSA failed to become undetectable within 1 year following irradiation or if hormonal therapy was initiated, the patient was censored for failure. Presurgical and pre-radiation PSA values, Gleason score, pathologic T stage, and reason for irradiation were analyzed for their impact on biochemical control. Results: The 5 year actuarial survival and disease-free survival rates for the entire group were 87.7% and 69.0%, respectively. The 5 year actuarial rate of biochemical control was 47.2%. Of 33 patients who were scored a biochemical failure, 21.3% did not achieve an undetectable PSA within 1 year. Patients were divided into 4 presurgical PSA groups: ≤4, >4 and ≤1 0, >10 and ≤20, and > 20 ng/ml. The 3 year actuarial rates of biochemical control were 100% for group 1, 66.7% for group 2, 61.5% for group 3, and 28.6% for group 4. Pre-RT PSA values were also evaluated. Univariate Cox models indicated lower presurgical and pre-RT PSA values were predictive of biochemical control (p=0.017, p<0.001). Gleason scores were divided into 3 groups: 2-4, 5-7, and 8-10. The 3 year actuarial rates of biochemical control were 50.0%, 80.0%, and 35.3%, respectively. By pairwise log rank test, biochemical control was significantly lower in group 3 than in group 2 (p=0.031). Group 1 (n=2) was too small for analysis. When stratified by T stage, the 3 year actuarial rates of biochemical control were as follows: T2: 20.0%, T3a: 72.4%, T3b: 85.7%, T3c: 56.2%, and T4: 0% (p<0.001). Patients treated adjuvantly (group 1) had a 3 year actuarial rate of biochemical control of 83.8%. For patients whose PSA failed to normalize within 6 months of surgery (group 2), the 3 year actuarial rate of biochemical control was 0% (n=2). For patients treated for a rising PSA >6 months after surgery (group 3), the 3 year actuarial rate of biochemical control was 55.6%. The 3 year actuarial rate of biochemical control for patients treated for a biopsy proven recurrence (group 4) was 8.3%. By pair-wise log rank test, the rates of biochemical control were significantly different between groups 1 and 3 (p=0.036), groups 1 and 4 (p<0.001), and groups 3 and 4 (p=0.009). Conclusion: Biochemical control was achieved in approximately half of the patients treated with post-operative prostatic fossa irradiation. Elevated presurgical and pre-RT PSA values, Gleason score ≥8, and biopsy proven recurrence were significantly predictive of biochemical failure. Patients treated adjuvantly were more likely to achieve biochemical control when compared to those with persistent or rising PSA values. Further study is needed to identify the subset of post-prostatectomy patients most likely to benefit from the addition of irradiation

[en] Purpose: The ASTRO Consensus Panel on PSA After Radiation Therapy recently recommended a definition of biochemical failure (BF) following treatment of prostate cancer with radiation therapy. We reviewed our institution's experience treating patients with external beam irradiation (RT) to determine if the Consensus Panel definition correlates with clinical distant metastases free survival (DMFS), disease free survival (DFS), cause specific survival (CSS), and local control (LC) rates for a large group of patients from the PSA era. Methods And Materials: Between 1/1/87 and 12/31/92, 653 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. Of these patients, 568 had a minimum follow-up of 2 years and constitute the study population. The median pre-treatment PSA and Gleason score was 11 ng/ml and 6, respectively. The median dose to the prostate using megavoltage RT was 66.6 Gy (range: 60-70.4 Gy) using a four field or arc technique. No patient received hormonal therapy either prior to, during, or after radiotherapy unless local or distant failure was documented. Pre-treatment and post-treatment serum PSA levels were recorded. Biochemical failure was defined as three consecutive increases in post-treatment PSA after achieving a nadir. Biochemical failure was recorded as the time midway between the nadir and first increase in PSA. Five year actuarial rates of DMFS, DFS, CSS, and LC were calculated for patients who were biochemically controlled (BC) versus those who failed biochemically. Results: Median follow-up was 56 months (range: 24-118 months). The overall 5 year actuarial rates of DMFS, DFS, CSS, and LC were significantly better in patients who were biochemically controlled versus those who were not (p< 0.001). The median time to DM within the BF group was 21 months (range: 2-112 months). When stratifying by pre-treatment PSA, Gleason score, and T stage, these differences remained significant for DMFS, DFS, and CSS. The Cox Proportional Hazards model demonstrated that BC was the single most important predictor of clinical outcome for DMFS, DFS, CSS, and LC. Pre-treatment PSA and Gleason score were also independent predictors of outcome for DMFS and DFS. Conclusions: The ASTRO Consensus Panel definition of BF following radiation therapy correlates well with clinical DMFS, DFS, and CSS. These findings imply that the Consensus Panel definition of PSA failure may be a surrogate for clinical progression and survival and should be considered a valid endpoint for separating successful versus unsuccessful treatment. Additional studies with longer follow-up will be needed to corroborate these findings

[en] Purpose: Active breathing control (ABC) temporarily immobilizes breathing. This may allow a reduction in treatment margins. This planning study assesses normal tissue irradiation and reproducibility using ABC for Hodgkin's disease. Methods and Materials: Five patients underwent CT scans using ABC obtained at the end of normal inspiration (NI), normal expiration (NE), and deep inspiration (DI). DI scans were repeated within the same session and 1-2 weeks later. To simulate mantle radiotherapy, a CTV1 was contoured encompassing the supraclavicular region, mediastinum, hila, and part of the heart. CTV2 was the same as CTV1 but included the whole heart. CTV3 encompassed the spleen and para-aortic lymph nodes. The planning target volume (PTV) was defined as CTV + 9 mm. PTVs were determined at NI, NE, and DI. A composite PTV (comp-PTV) based on the range of NI and NE PTVs was determined to represent the margin necessary for free breathing. Lung dose-mass histograms (DMH) for PTV1 and PTV2 and cardiac dose-volume histograms (DVH) for PTV3 were compared at the three different respiratory phases. Results: ABC was well-tolerated by all patients. DI breath-holds ranged from 34 to 45 s. DMHs determined for PTV1 revealed a median reduction in lung mass irradiated at DI of 12% (range, 9-24%; n = 5) compared with simulated free-breathing. PTV2 comparisons also showed a median reduction of 12% lung mass irradiated (range, 8-28%; n = 5). PTV3 analyses revealed the mean volume of heart irradiated decreased from 26% to 5% with deep inspiration (n = 5). Lung volume comparisons between intrasession and intersession DI studies revealed mean variations of 4%. Conclusion: ABC is well tolerated and reproducible. Radiotherapy delivered at deep inspiration with ABC may decrease normal tissue irradiation in Hodgkin's disease patients

[en] Purpose: For tumors in the thorax and abdomen, reducing the treatment margin for organ motion due to breathing reduces the volume of normal tissues that will be irradiated. A higher dose can be delivered to the target, provided that the risk of marginal misses is not increased. To ensure safe margin reduction, we investigated the feasibility of using active breathing control (ABC) to temporarily immobilize the patient's breathing. Treatment planning and delivery can then be performed at identical ABC conditions with minimal margin for breathing motion. Methods and Materials: An ABC apparatus is constructed consisting of 2 pairs of flow monitor and scissor valve, 1 each to control the inspiration and expiration paths to the patient. The patient breathes through a mouth-piece connected to the ABC apparatus. The respiratory signal is processed continuously, using a personal computer that displays the changing lung volume in real-time. After the patient's breathing pattern becomes stable, the operator activates ABC at a preselected phase in the breathing cycle. Both valves are then closed to immobilize breathing motion. Breathing motion of 12 patients were held with ABC to examine their acceptance of the procedure. The feasibility of applying ABC for treatment was tested in 5 patients by acquiring volumetric scans with a spiral computed tomography (CT) scanner during active breath-hold. Two patients had Hodgkin's disease, 2 had metastatic liver cancer, and 1 had lung cancer. Two intrafraction ABC scans were acquired at the same respiratory phase near the end of normal or deep inspiration. An additional ABC scan near the end of normal expiration was acquired for 2 patients. The ABC scans were also repeated 1 week later for a Hodgkin's patient. In 1 liver patient, ABC scans were acquired at 7 different phases of the breathing cycle to facilitate examination of the liver motion associated with ventilation. Contours of the lungs and livers were outlined when applicable. The variation of the organ positions and volumes for the different scans were quantified and compared. Results: The ABC procedure was well tolerated in the 12 patients. When ABC was applied near the end of normal expiration, the minimal duration of active breath-hold was 15 s for 1 patient with lung cancer, and 20 s or more for all other patients. The duration was greater than 40 s for 2 patients with Hodgkin's disease when ABC was applied during deep inspiration. Scan artifacts associated with normal breathing motion were not observed in the ABC scans. The analysis of the small set of intrafraction scan data indicated that with ABC, the liver volumes were reproducible at about 1%, and lung volumes to within 6%. The excursions of a 'center of target' parameter for the livers were less than 1 mm at the same respiratory phase, but were larger than 4 mm at the extremes of the breathing cycle. The inter-fraction scan study indicated that daily setup variation contributed to the uncertainty in assessing the reproducibility of organ immobilization with ABC between treatment fractions. Conclusion: The results were encouraging; ABC provides a simple means to minimize breathing motion. When applied for CT scanning and treatment, the ABC procedure requires no more than standard operation of the CT scanner or the medical accelerator. The ABC scans are void of motion artifacts commonly seen on fast spiral CT scans. When acquired at different points in the breathing cycle, these ABC scans show organ motion in three-dimension (3D) that can be used to enhance treatment planning. Reproducibility of organ immobilization with ABC throughout the course of treatment must be quantified before the procedure can be applied to reduce margin for conformal treatment

[en] Purpose: The clinical significance of postradiotherapy (RT) prostate biopsy characteristics is not well understood relative to the known prognostic factors. We performed a detailed pathologic review of posttreatment biopsy specimens in an attempt to clarify their relationship with clinical outcome and radiation dose. Methods and Materials: Between 1991 and 1998, 78 patients with locally advanced prostate cancer were prospectively treated with external beam RT in combination with high-dose-rate brachytherapy at William Beaumont Hospital and had post-RT biopsy material available for a complete pathologic review. Patients with any of the following characteristics were eligible for study entry: pretreatment prostate-specific antigen level ≥10.0 ng/mL, Gleason score ≥7, or clinical Stage T2b-T3cN0M0. Pelvic external beam RT (46.0 Gy) was supplemented with three (1991-1995) or two (1995-1998) ultrasound-guided transperineal interstitial ¹⁹²Ir high-dose-rate implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy per implant. Post-RT prostate biopsies were performed per protocol at a median interval of 1.5 years after RT. All pre- and post-RT biopsy specimen slides from each case were reviewed by a single pathologist (N.S.G.). The presence and amount of residual cancer, most common RT-effect score, and least amount RT-effect score were analyzed. The median follow-up was 5.7 years. Biochemical failure was defined as three consecutive prostate-specific antigen rises. Results: Forty patients (51%) had residual cancer in the post-RT biopsies. The 7-year biochemical control rate was 79% for patients with negative biopsies vs. 62% for those with positive biopsies with marked RT damage vs. 33% for those with positive biopsies with no or minimal RT damage. A greater percentage of positive pre-RT biopsy cores (p=0.01), lower total RT dose (p=0.001), lower dose per implant (p=0.001), and greater percentage of positive post-RT biopsy cores (p=0.01) were each associated with biochemical failure (Cox regression, univariate analysis). For patients with <25% positive post-RT biopsy cores, the 7-year biochemical control rate was 81% vs. a 62% biochemical control rate for those with 25-49% positive cores and only 32% for those with ≥50% positive cores (p=0.01). On Cox multiple regression analysis, only the percentage of positive pre-RT biopsy cores and RT dose remained significantly associated with biochemical failure. Of all the factors analyzed, only the pretreatment cancer volume and lower RT dose were significantly associated with residual cancer and/or residual cancer with no or minimal RT damage. A greater percentage of positive pre-RT biopsy cores was associated with both a positive post-RT biopsy (p=0.08) and a greater percentage of positive post-RT biopsy cores (p=0.04). A lower total RT dose was associated with both a positive post-RT biopsy (p=0.08) and a greater percentage of positive post-RT biopsy cores (p=0.02). For patients who received <80 Gy (equivalent in 2-Gy fractions), 73% had positive post-RT biopsies vs. a 56% biopsy positivity rate for those who received 84-90 Gy and only 39% for those who received ≥92 Gy (p=0.07). Conclusion: Patients with positive post-RT biopsies are more likely to experience biochemical failure, especially when the RT damage is minimal. Patients who have a larger pretreatment tumor volume or receive a lower RT dose are more likely to demonstrate post-RT biopsy positivity and biochemical failure

[en] Purpose: Biochemical control using serial posttreatment serum prostate specific antigen (PSA) levels is being increasingly used to assess treatment efficacy for localized prostate cancer. However, no standardized definition of biochemical control has been established. We reviewed our experience treating patients with localized prostate cancer and applied three different commonly used definitions of biochemical control to determine if differences in therapeutic outcome would be observed. Methods and Materials: Between January 1987 and December 1991, 480 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. The median dose to the prostate was 66.6 Gy (range 58-70.4) using a four-field or arc technique. Pretreatment and posttreatment serum PSA levels were recorded. Over 86% (414 of 480) of patients had a pretreatment PSA level available. Three different definitions of biochemical control were used: (a) PSA nadir < 1 ng/ml within 1 year of treatment completion. After achieving nadir, if two consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase; (b) PSA nadir < 1.5 ng/ml within 1 year of treatment completion. After achieving nadir, if two consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase; (c) Posttreatment PSA nadir < 4 ng/ml without a time limit. Once the nadir was achieved, if it did not rise above normal the patient was considered to be biochemically controlled. Clinical local control was defined as no palpable prostate nodularity beyond 18 months, no new prostate nodularity, or a negative prostate biopsy. Results: Median follow-up was 48 months (range 3-112). Pretreatment PSA values were correlated with treatment outcome using the three definitions of biochemical control as well as clinical local control. Pretreatment PSA values were stratified into five groups (Group 1: PSA < 4; Group 2: PSA 4-10; Group 3: PSA 10-15; Group 4: PSA 15-20; and Group 5: PSA > 20), and 5-year actuarial rates of biochemical control were calculated using the three biochemical control and one clinical local control definitions. For Group 1, 5-year actuarial rates of biochemical control were 84%, 90%, and 96% for Definitions 1-3 and clinical local control, respectively. For Group 2, 5-year actuarial control rates were 45%, 54%, 74%, and 92% for the four definitions, respectively. For Group 3, 5-year actuarial control rates were 26%, 31%, 63%, and 100% for the four definitions, respectively. For Group 4, 5-year actuarial control rates were 24%, 24%, 50%, and 100% for the four definitions, respectively. Finally, for Group 5, 5-year actuarial control rates were 5%, 14%, 15%, and 89% for the four definitions, respectively. Depending on the definition used, statistically significant differences overall in outcome rates were observed. Differences between all four definitions for all pairwise comparisons ranged from 5 to 53% (p < 0.001). Conclusion: When different definitions of biochemical control are used in assessing treatment outcome, significantly different rates of success are noted. Until a standardized definition of biochemical control is adopted, differences in treatment outcome cannot be meaningfully compared

[en] Purpose: Prostate specific antigen (PSA) has been established as the most important prognostic factor for prostate cancer. We reviewed our experience treating patients with clinically localized prostate cancer with external beam irradiation (RT) to evaluate if previously defined clinical and treatment related prognostic factors remain valid when biochemical control was used as an end-point to evaluate results. Methods and Materials: Between 1/87 and 12/91, 480 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. The median dose to the prostate was 66.6 Gy (range 58 - 70.4 Gy) using a 4 field or arc technique. Pre- and post-treatment serum PSA levels were recorded. Biochemical control was defined as PSA nadir ≤ 1.5 ng/ml within 1 year of treatment completion. After achieving nadir, if 2 consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase. Patients (pts) were divided into 3 groups according to total number of days on treatment: ≤ 49 days (≤ 7 weeks)- 21 pts; 50-63 days (8-9 weeks)- 429 pts; and ≥ 64 days (≥ 9 weeks)- 15 pts. Patients were also divided into groups with respect to the method of diagnosis: TURP (81 pts), or other means (399 pts). Patients were further divided into 2 groups: 1) if they had ever had a pre-treatment TURP (170 pts) or 2) if they had not (310 pts). Patients were divided into 2 groups according to boost technique: bilateral arcs (459 pts) or 4 field box (21 pts). Patients were also divided into groups according to total RT dose: ≤ 70 Gy (421 pts) or > 70 Gy (59 pts). Patients were further subdivided into 3 dose groups: < 60 Gy (3 pts); 60 - 70 Gy (418 pts); and > 70 Gy (59 pts). Results: Median follow-up is 48 months (range 3 - 112 months). No statistically significant difference in rates of biochemical control were noted for treatment time, overall time (date of biopsy to completion of RT), or treatment time divided into 3 groups (≤ 7 weeks, 8-9 weeks, and ≥ 9 weeks). No differences were seen when controlling for pre-treatment PSA, T stage, or Gleason score. Patients diagnosed by TURP had a significant improvement (p< .026) in actuarial rate of biochemical control (5 year: 58% vs. 39%) but this significance disappeared when controlling for either pre-treatment PSA, T stage, or Gleason score. There was no statistically significant difference in biochemical control between patients who had pre-treatment TURPs and those who had never had a TURP. No statistically significant difference in rate of biochemical control was noted between patients treated with different boost techniques. Statistically significant differences in biochemical control were noted for pts receiving different RT doses (≤ 70 Gy- 34% vs. > 70 Gy- 22% or < 60 Gy- 50%; 60-70 Gy- 33%; > 70 Gy- 22%) but this significance disappeared when controlling for either pre-treatment PSA, T stage, or Gleason score. Conclusion: No significant effect of overall treatment time, pre-treatment TURP, boost technique, or total dose was noted on outcome in patients treated with external RT when biochemical control was used as an end-point