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Gerald E Hanks

Publications and source records attributed to Gerald E Hanks.

At least 19 recordsLinked to original sources

Posttreatment prostatic-specific antigen doubling time as a surrogate endpoint for prostate cancer-specific survival: an analysis of Radiation Therapy Oncology Group Protocol 92-02.

PURPOSE: We evaluated whether posttreatment prostatic-specific antigen doubling time (PSADT) was predictive of prostate cancer mortality by testing the Prentice requirements for a surrogate endpoint. METHODS AND MATERIALS: We analyzed posttreatment PSA measurements in a cohort of 1,514 men with localized prostate cancer (T2c-4 and PSA level <150 ng/mL), treated and monitored prospectively on Radiation Therapy Oncology Group Protocol 92-02. From June 1992 to April 1995, men were randomized to neoadjuvant androgen deprivation and 65-70 Gy of radiation therapy (n = 761), or in combination with 24 months of adjuvant androgen deprivation (n = 753). Using an adjusted Cox proportional hazards model, we tested if PSADT was prognostic and independent of randomized treatment in this cohort. The endpoints were time to PSADT (assuming first-order kinetics for a minimum of 3 rising PSA measurements) and cancer-specific survival (CSS). RESULTS: After a median follow-up time of 5.9 years, randomized treatment was a significant predictor for CSS (p(Cox) = 0.002), PSADT <6 months (p(Cox) < 0.001), PSADT <9 months (p(Cox) < 0.001), and PSADT <12 months (p(Cox) < 0.001) but not for PSADT <3 (p(Cox) = 0.4). The significant posttreatment PSADTs were also significant predictors of CSS (p(Cox)< 0.001). After adjusting for T stage, Gleason score and PSA, all of Prentice's requirements were not met, indicating that the effect of PSADT on CSS was not independent of the randomized treatment. CONCLUSIONS: Prostatic specific antigen doubling time is significantly associated with CSS, but did not meet all of Prentice's requirements for a surrogate endpoint of CSS. Thus, the risk of dying of prostate cancer is not fully explained by PSADT.

Adult↗

Definitions of biochemical failure that best predict clinical failure in patients with prostate cancer treated with external beam radiation alone: a multi-institutional pooled analysis.

PURPOSE: Pooled data on 4,839 patients with T1-2 prostate cancer treated with external beam radiation therapy (RT) alone at 9 institutions have previously provided long-term biochemical failure (BF) and clinical outcomes using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition. In this report we determined the sensitivity and specificity of several BF definitions using distant failure (DF) alone or clinical failure (CF), defined as local failure (LF) and/or DF. MATERIALS AND METHODS: The pooled cohort was treated between 1986 and 1995 with external beam RT (60 Gy or greater) without pre-RT androgen suppression or planned post-RT adjuvant androgen suppression. Median followup was 6.3 years. The sensitivity and specificity of 102 definitions of BF relative to DF and LF were assessed. RESULTS: The BF definitions with higher sensitivity and specificity than the ASTRO definition for DF only and CF are reported. The sensitivity and specificity of the ASTRO definition to predict DF alone was 55% and 68%, respectively. Three definitions had higher sensitivity and specificity, namely prostate specific antigen (PSA) greater than current nadir (lowest PSA prior to current measurement) plus 3 ng/ml (sensitivity 76% and specificity 72%), dated at the call (failure date as the date when the criterion was met), PSA greater than absolute nadir plus 2 ng/ml (sensitivity 72% and specificity 70%), dated at the call, or 2 consecutive increases of at least 0.5 ng/ml, back dated (sensitivity 69% and specificity 73%). The sensitivity and specificity of the ASTRO definition to predict CF was 60% and 72%, respectively. Three definitions had higher sensitivity and specificity, namely PSA greater than current nadir plus 3 ng/ml (sensitivity 66% and specificity 77%), dated at the call, PSA greater than absolute nadir plus 2 ng/ml (sensitivity 64% and specificity 74%), dated at the call, or 2 consecutive increases of at least 0.5 ng/ml, back dated (sensitivity 67% and specificity 78%). CONCLUSIONS: Using what is to our knowledge the largest data set of patients with prostate cancer treated with RT alone we correlated multiple definitions of BF with the strict clinical end points of DF alone and CF (DF or local failure). Defining BF as PSA greater than absolute nadir plus 2 ng/ml, dated at the call, PSA greater than current nadir plus 3 ng/ml, dated at the call, or 2 consecutive increases of at least 0.5 ng/ml, back dated, had higher sensitivity and specificity for DF alone or CF compared with the ASTRO definition. This information should contribute to the discussion regarding suggested modifications to the ASTRO definition of biochemical failure.

Adult↗

Changing trends in national practice for external beam radiotherapy for clinically localized prostate cancer: 1999 Patterns of Care survey for prostate cancer.

PURPOSE: To report changing trends in external beam radiotherapy (EBRT) delivery practice for clinically localized prostate cancer as determined from the 1999 survey from the American College of Radiology National Patterns of Care Study. METHODS AND MATERIALS: The 1999 survey included a weighted sample of 36,496 patient records obtained from a stratified two-stage sample of 554 patient records. Patients were surveyed from 58 institutions and were treated between January 1999 and December 1999. Of these, 36% (weighted sample size, 13,293; unweighted sample size, 162) were treated with brachytherapy with or without EBRT and 64% (weighted sample size, 23,203; unweighted sample size, 392) were treated with EBRT only. The latter group is the subject of this report. The following trends in clinical practice were analyzed according to prognostic risk groups and other variables and compared with the results of the prior surveys: use of androgen deprivation therapy (ADT) in combination with EBRT, higher prescription dose levels, and administration of elective whole pelvic RT (WPRT). RESULTS: The incidence of ADT use for favorable, intermediate, and unfavorable-risk groups was 31%, 54%, and 79%, respectively. A multivariate logistic regression analysis revealed a statistically significantly increased likelihood of intermediate (p = 0.001) and unfavorable (p <0.0001) risk groups treated with ADT in conjunction with EBRT compared with favorable-risk patients. ADT use was more prevalent among treated patients in the 1999 survey than in the 1994 survey (51% vs. 8%, p <0.0001). Compared with the prior survey, a greater percentage of patients were treated with higher radiation doses in the 1999 survey (> or =72 Gy, 45% in 1999 vs. 3% in 1994, p <0.0001). In the 1999 survey, the proportion of patients with favorable, intermediate, and unfavorable tumors treated to doses > or =72 Gy was 43%, 38%, and 60%, respectively, compared with 4%, 3%, and 1%, respectively, in the 1994 survey. Compared with the 1994 survey, a large increase in the number of patients treated with brachytherapy (36% vs. 3%, p <0.0001). The frequency of WPRT use decreased from 92% in 1989 to 52% in 1994 to 23% in 1999. For the 1999 survey, a multivariate analysis indicated that unfavorable-risk patients (p = 0.016) and intermediate-risk patients (p = 0.018) were more likely to be treated with WPRT compared with favorable-risk patients. Nevertheless, even among unfavorable-risk patients, a substantial decline had occurred in the use of WPRT for the 1999 survey (70% for the 1994 survey compared with the 31% for the current survey; p = 0.003). CONCLUSION: The significantly increased use of ADT for high-risk patients and higher radiation doses, especially for intermediate- and high-risk patients, reflects the penetration and growing acceptance of clinical trial results that have demonstrated the efficacy of these treatment approaches. The relatively high proportion of favorable-risk patients treated with high radiation dose levels was greater than expected. A large increase in brachytherapy was observed compared with prior surveys. Most treated patients with high-risk disease did not undergo elective WPRT, which likely reflects the influences of prior trials, stage migration, and the commonly held belief that WPRT provides minimal benefit in the setting of higher radiation doses.

Aged↗

Short-term androgen deprivation and PSA doubling time: their association and relationship to disease progression after radiation therapy for prostate cancer.

PURPOSE: The goal of this study was to investigate the relationship between PSA doubling time (PSADT) and initial management of prostate cancer with short-term androgen deprivation (STAD) and the impact of these factors on disease progression after radiation therapy. METHODS AND MATERIALS: Between May 1989 and October 1998, 284 patients treated with 3D-CRT experienced biochemical failure (BF) as defined under the ASTRO consensus statement. All patients had sufficient follow-up data for PSADT calculations. Linear regression was used to assess predictors of PSADT among STAD, time to biochemical failure (TTBF), Gleason Score, tumor stage, dose, posttreatment PSA nadir, pretreatment PSA, and age. A composite covariate was created from the various combinations of factors found to be predictive of PSADT. The composite covariate was then included, along with PSADT and the factors previously mentioned, in proportional hazards modeling of freedom from distant metastasis (FDM), cause-specific survival (CSS), and overall survival (OS). RESULTS: Fifty-four (19%) patients developed distant metastasis, 20 (7%) died of prostate cancer, and 53 (19%) died of any cause. The median PSADT was 12 months. Predictors of a longer PSADT were TTBF >12 months, Gleason Score 2-6, and STAD. An ordinal composite covariate was created with eight levels on the basis of the magnitude of observed mean PSADT within the eight possible combinations of the three dichotomized predictors. The most significant predictor of higher FDM rates in Cox modeling was the composite covariate, followed by longer PSADT, STAD, lower PSA nadir, higher RT dose, and Gleason Score 2-6. Predictors of higher CSS rates were lower nadir, longer PSADT, T1/T2ab tumors, the composite covariate, and STAD. The most significant predictor of a higher OS rate was STAD, followed by longer PSADT, younger age at diagnosis, the composite covariate, lower nadir, and T1/T2ab tumors. CONCLUSIONS: Longer TTBF, Gleason Score 2-6 tumors, and STAD were predictive of longer PSADT. Even after adjusting for these factors in the capacity of their predictive properties for PSADT, STAD and observed PSADT continued to be significant independent predictors of FDM, CSS, and OS. STAD appears to have a pronounced impact on disease progression, probably the result partly of the prolongation of PSADT.

Aged↗

Prostate cancer radiotherapy dose response: an update of the fox chase experience.

PURPOSE: The effectiveness of increasing radiotherapy dose for men with prostate cancer was evaluated with reference to prognostic groups as defined by pretreatment serum prostate specific antigen (PSA), Gleason score, T stage and perineural invasion. MATERIALS AND METHODS: There were 839 men treated between April 1989 and December 1997 with conformal radiotherapy alone. Cox multivariate analysis was used to establish important predictors of biochemical failure (BF) separately for patients with an initial pretreatment PSA (iPSA) of less than 10, 10 to 19.9, or 20 or greater ng/ml. Radiotherapy (RT) dose was evaluated as a continuous and categorical (dose groups of less than 72, 72 to 75.9 and 76 Gy or greater) variable. RESULTS: At a median 63-month followup multivariate analysis demonstrated that iPSA and radiotherapy (RP) dose were the most significant predictors of BF, followed by Gleason score and T stage. Perineural invasion was not an independent correlate of outcome. RT dose was significant in all iPSA groups (less than 10, 10 to 19.9 and 20 or greater ng/ml). Gleason score was significant when iPSA was less than 10 ng/ml. T stage was significant when iPSA was 20 ng/ml or greater and it was borderline when iPSA was 10 to 19.9 ng/ml (p = 0.08). Prognostic subgroups were derived from these results and tested for an effect of RT dose on univariate analysis. Radiation dose was not a correlate of BF in the most favorable (PSA less than 10 ng/ml and Gleason score 2 to 6) and the most unfavorable (PSA 20 ng/ml or greater and stage T3-T4) prognostic groups but it was otherwise an influential determinant of outcome. CONCLUSIONS: RT dose escalation to 76 Gy or greater improved patient outcome for all prognostic groups except those at the favorable and unfavorable extremes.

Adult↗

Matched-cohort analysis of patients with prostate cancer followed with observation or treated with three-dimensional conformal radiation therapy.

OBJECTIVES: To compare the outcome of similar patients with prostate cancer treated by either observation or three-dimensional conformal radiation therapy (3-DCRT). PATIENTS AND METHODS: The study included 69 patients with nonmetastatic prostate cancer who were observed only; the indications included indolent disease, significant medical comorbidities and refusal of treatment. Of these, 62 patients had palpable T1-T2a and seven T2b-T3a disease, a median Gleason score of 6 and a median initial prostate-specific antigen (PSA) level of 5.3 ng/mL. A matched-cohort analysis of 69 patients, based on palpation T category, Gleason score and initial PSA, was used to compare the outcome between the observation and 3-DCRT groups. The median radiation dose for latter was 72 Gy. RESULTS: The median follow-up for the observed patients was 49 months. The 5- and 8-year actuarial rates of freedom from distant metastases were 100% and 93%, respectively, and the actuarial overall survival rates 94% and 73%, respectively. Seven observed patients had local disease progression on physical examination. Four patients who initially were observed received radiation therapy later for a rising PSA and/or local disease progression. For the 69 matched 3-DCRT patients, the overall 5-year rate for no biochemically evident disease was 74%. The respective 5- and 8-year actuarial rates of freedom from distant metastases were 95% and 95%, and actuarial overall survival rates 95% and 75%. There were no significant differences in distant metastasis and overall survival rates between the groups, and no deaths from prostate cancer in either group. CONCLUSIONS: Observation is a reasonable alternative to treatment in selected patients. During the 5-year follow-up the progression rates were relatively low, and there was no difference in distant metastasis or overall survival between the groups. As the follow-up was short a longer follow-up is needed to determine whether the outcome of those patients who chose observation will remain comparable to that in those undergoing immediate 3-DCRT.

Adenocarcinoma↗

Phase III trial of long-term adjuvant androgen deprivation after neoadjuvant hormonal cytoreduction and radiotherapy in locally advanced carcinoma of the prostate: the Radiation Therapy Oncology Group Protocol 92-02.

PURPOSE: Radiation Therapy Oncology Group (RTOG) Protocol 92-02 was a randomized trial testing long-term (LT) adjuvant androgen deprivation (AD) after initial AD with external-beam radiotherapy (RT) in patients with locally advanced prostate cancer (PC; T2c-4) and with prostate-specific antigen level less than 150 ng/mL. PATIENTS AND METHODS: Patients received a total of 4 months of goserelin and flutamide, 2 months before and 2 months during RT. A radiation dose of 65 to 70 Gy was given to the prostate and a dose of 44 to 50 Gy to the pelvic lymph nodes. Patients were randomly assigned to receive no additional therapy (short-term [ST]AD-RT) or 24 months of goserelin (LTAD-RT); 1,554 patients were entered onto the study. RESULTS: The LTAD-RT arm showed significant improvement in all efficacy end points except overall survival (OS; 80.0% v 78.5% at 5 years, P =.73), compared with the STAD-RT arm. In a subset of patients not part of the original study design, with tumors assigned Gleason scores of 8 to 10 by the contributing institutions, the LTAD-RT arm had significantly better OS (81.0% v 70.7%, P =.044). There was a small but significant increase in the frequency of late radiation grades 3, 4, and 5 gastrointestinal toxicity ascribed to the LTAD-RT arm (2.6% v 1.2% at 5 years, P =.037), the cause of which is not clear. CONCLUSION: The RTOG 92-02 trial supports the addition of LT adjuvant AD to STAD with RT for T2c-4 PC. In the exploratory subset analysis of patients with Gleason scores 8 to 10, LT adjuvant AD resulted in a survival advantage.

Adenocarcinoma↗

Biochemical failure as a determinant of distant metastasis and death in prostate cancer treated with radiotherapy.

PURPOSE: Biochemical failure (BF), defined by a rising prostate-specific antigen (PSA) profile, is an early surrogate of treatment failure. However, little evidence is available to show that BF is associated with death for patents with prostate cancer treated with radiotherapy. We examined the relationship between BF and death from prostate cancer. METHODS AND MATERIALS: A total of 942 patients were treated between 1987 and 1998 with external beam radiotherapy who had sufficient PSA determinations in follow-up for the analyses described. The median radiation dose was 72 Gy, median PSA was 9.9 ng/mL, and median follow-up was 73 months. The American Society for Therapeutic Radiology and Oncology consensus definition was used to define BF. Kaplan-Meier calculations were from the start of radiotherapy. Cox proportional hazards regression multivariate analyses were used to investigate the association of BF (time-dependent variable) and other factors to distant metastasis (DM), cause-specific death (CSD), and overall death (OD). The year of treatment was included in some of the multivariate analyses to correct for potential unknown factors that may have occurred during the years of the study, such as stage migration. RESULTS: BF was observed in 316 patients (34%), and 66 (7%) experienced DM, 32 (3%) died of prostate cancer, and 230 (24%) died overall during the study period. The Kaplan-Meier 5-year rate estimates from the start of treatment for BF, DM, CSD, and OD were 38%, 6%, 3%, and 13%, respectively. All patients with DM had BF. In multivariate analyses, BF was associated with DM and CSD, but not OD. The inclusion of the year of treatment did not alter these relationships. CONCLUSION: BF, as a time-dependent covariate, was the strongest determinant of DM and was also very significantly related to CSD. The inclusion of the year of treatment had little effect on these associations. Longer follow-up is needed to determine conclusively the relationship of BF to OD.

Aged↗

Validation of a treatment policy for patients with prostate specific antigen failure after three-dimensional conformal prostate radiation therapy.

BACKGROUND: The objective of this report was to present an outcomes validation for the Fox Chase Cancer Center (FCCC) management policy for patients who demonstrate prostate specific antigen (PSA) failure after receiving three-dimensional conformal radiation therapy (3DCRT). METHODS: Eligible patients included 248 men with T1-T3N0M0 prostate carcinoma who demonstrated PSA failure (according to the American Society for Therapeutic Radiology and Oncology definition) after completing definitive 3DCRT alone or with androgen deprivation (AD) therapy between May 1989 and November 1997. The primary endpoint evaluated was freedom from distant metastasis (FDM). The secondary endpoints evaluated included cause specific survival (CSS) and overall survival (OS). The variables evaluated in the multivariate analyses (MVA) included initial PSA, Gleason score, T classification, dose, PSA nadir, time to PSA failure, PSA doubling time (PSADT), initial use of AD therapy, and the use of AD therapy upon PSA failure. RESULTS: The 5-year FDM, CSS, and OS rates for the entire group were 76%, 92%, and 76%, respectively. It was found that four variables were independent predictors of FDM: Gleason score (P = 0.0039), PSA nadir (P = 0.0001), PSADT (P = 0.0001), and the use of AD on PSA failure (P = 0.0001). One hundred forty-eight men demonstrated a PSADT < 12 months. AD therapy was started in 59 men, and 89 men refused AD therapy and were observed. The use of AD therapy was associated with a significant improvement in the 5-year FDM rate (57% vs. 78%; P = 0.0026). In the group of men with PSADT < 12 months, the median time to distant failure was significantly longer in the men who received AD therapy (6 months vs. 25 months; P = 0.02). Of the 100 men with a PSADT > or = 12 months, 89 men were observed, and 11 men received AD therapy. There was no improvement in the 5-year FDM rate with the use of AD therapy compared with observation (88% vs. 92%, respectively; P = 0.74). CONCLUSIONS: The current results validate the use of PSADT as an indicator of patients who may be observed expectantly or treated with AD therapy for PSA failure after 3DCRT. Prospective trials are needed to define further the optimal treatment for these patients.

Algorithms↗

Late morbidity profiles in prostate cancer patients treated to 79-84 Gy by a simple four-field coplanar beam arrangement.

PURPOSE: To describe the frequency and magnitude of late GI and GU morbidity in prostate cancer patients treated to high dose levels with a simple three-dimensional conformal technique. METHODS AND MATERIALS: A total of 156 intermediate- and high-risk patients were treated between January 1, 1992 and February 28, 1999 with a simple four-field three-dimensional conformal technique to 79-84 Gy. All patients were treated with a four-field conformal technique; the prostate received 82 Gy and the seminal vesicles and periprostatic tissue 46 Gy. GI and GU toxicity was scored according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Morbidity Grading Scale and compared using Kaplan-Meier estimates. RESULTS: The late Grade 2 GI complication rate was 9% and 38% at 3 years for patients treated with and without rectal blocking, respectively (p = 0.0004). No Grade 3 late GI complications developed. The rate of Grade 2 late GU complications was 5%, 8%, and 12% at 12, 24, and 36 months, respectively. The Grade 3 late GU complication rate was 2% at 36 months. These differences were not statistically significant. CONCLUSION: The treatment method described is a simple four-field conformal technique that can be easily implemented in the general radiation community. A dose of 79-84 Gy can be safely delivered to the prostate, with a 9% rate of late Grade 2 GI, 12% rate of late Grade 2 GU, and 2% rate of late Grade 3 GU complications.

Digestive System↗

Free prostate-specific antigen improves prostate cancer detection in a high-risk population of men with a normal total PSA and digitalrectal examination.

OBJECTIVES: Uncertainty exists regarding optimal prostate cancer screening parameters for high-risk populations. The purpose of this study is to report the use of percent free prostate-specific antigen (PSA) as an indication for biopsy in men at increased risk for developing prostate cancer who have a normal digital rectal examination (DRE) and total PSA level between 2 and 4 ng/mL. METHODS: African-American men and men with at least one first-degree relative with prostate cancer are eligible for enrollment into the Prostate Cancer Risk Assessment Program (PRAP) at our institution. Between October 1996 and April 2002, 310 asymptomatic high-risk men with no history of prostate cancer, benign prostatic hyperplasia (BPH), or prostatic intraepithelial neoplasia (PIN) were screened in the PRAP with DRE and total PSA. Percent free PSA was obtained in men with a total PSA between 2 and 10 ng/mL. Men with a normal DRE and total PSA between 2 and 4 ng/mL were advised to undergo transrectal ultrasound-guided (TRUS) biopsies of the prostate if the percent free PSA was less than 27%. Other indications for biopsy included an abnormal DRE or a total PSA greater than 4 ng/mL. The primary endpoint evaluated was prostate cancer detection in high-risk men with a benign prostate examination, a normal total PSA between 2 and 4 ng/mL, and percent free PSA less than 27%. RESULTS: Of the 310 men, 174 (56%) were African American and 202 (65%) had at least one first-degree relative with prostate cancer. Sixty-two of the 310 men were referred for prostate biopsy, and 40 of 62 had biopsy performed. Twenty-one of 40 men were diagnosed with prostate cancer for a cancer detection rate of 53% in all men undergoing biopsy and an overall cancer detection rate of 6.8% in this high-risk population. Thirty-seven high-risk men (median age 54 years) with a total PSA level between 2 and 4 ng/mL (median 2.7 ng/mL) and a normal DRE were found to have a percent free PSA level of less than 27% (median 16%, range 8% to 25%). Twenty-three of these 37 men (62%) proceeded with the recommended prostate biopsy. Prostatic adenocarcinoma was diagnosed in 12 of 23 men for a cancer detection rate of 52% in men undergoing biopsy and 32% in all men with a normal DRE, a total PSA between 2 and 4 ng/mL, and a percent free PSA less than 27%. All positive biopsies demonstrated clinically significant Gleason score 6 or 7 disease. In all men electing radical prostatectomy, bilateral organ-confined disease (pT2bN0M0) was confirmed. CONCLUSIONS: In this unique population of men at high risk for prostate cancer, a percent free PSA of less than 27% was found to be useful for detecting early-stage but clinically significant cancers in men with a total PSA value between 2 and 4 ng/mL and normal DRE findings.

Biopsy, Needle↗

Positive prostate biopsy laterality and implications for staging.

OBJECTIVES: To examine the effect of including positive prostate biopsy information in palpation staging (2002 system) and the influence of this information on freedom from biochemical failure (bNED). Prostate biopsy laterality status (unilateral versus bilateral positive) is part of clinical staging using American Joint Commission on Cancer criteria, but is rarely used. METHODS: From April 1, 1989 to September 30, 1999, 1038 patients with palpable T1-T3Nx-0M0 prostate cancer were treated with three-dimensional conformal radiotherapy alone. Kaplan-Meier bNED curves were compared using the log-rank test. The Cox proportional hazards regression model of bNED was used for multivariate analysis. RESULTS: The median follow-up was 46 months. The proportion of patients with bilateral positive biopsies by palpation category T1c was 24%, by T2a was 17%, by T2b was 26%, by T2c was 65%, and by T3 was 53%. No statistically significant difference was noted in bNED on the basis of biopsy laterality status for the palpation T stages T1c, T2a, T2b, or T3. A statistically significant difference in the 5-year bNED in the T2c stage was found; those with unilateral positive biopsies fared worse (46% versus 74%, respectively, P = 0.04). CONCLUSIONS: Inclusion of positive biopsy laterality status into clinical staging causes stage migration without reflecting a change in outcome and should not be used.

Aged↗

Impact of target volume coverage with Radiation Therapy Oncology Group (RTOG) 98-05 guidelines for transrectal ultrasound guided permanent Iodine-125 prostate implants.

PURPOSE: Despite the wide use of permanent prostate implants for the treatment of early stage prostate cancer, there is no consensus for optimal pre-implant planning guidelines that results in maximal post-implant target coverage. The purpose of this study was to compare post-implant target volume coverage and dosimetry between patients treated before and after Radiation Therapy Oncology Group (RTOG) 98-05 guidelines were adopted using several dosimetric endpoints. MATERIALS AND METHODS: Ten consecutively treated patients before the adoption of the RTOG 98-05 planning guidelines were compared with ten consecutively treated patients after implementation of the guidelines. Pre-implant planning for patients treated pre-RTOG was based on the clinical target volume (CTV) defined by the pre-implant TRUS definition of the prostate. The CTV was expanded in each dimension according to RTOG 98-05 and defined as the planning target volume. The evaluation target volume was defined as the post-implant computed tomography definition of the prostate based on RTOG 98-05 protocol recommendations. Implant quality indicators included V(100), V(90), V(100), and Coverage Index (CI). RESULTS: The pre-RTOG median V(100), V(90), D(90), and CI values were 82.8, 88.9%, 126.5 Gy, and 17.1, respectively. The median post-RTOG V(100), V(90), D(90), and CI values were 96.0, 97.8%, 169.2 Gy, and 4.0, respectively. These differences were all statistically significant. CONCLUSIONS: Implementation of the RTOG 98-05 implant planning guidelines has increased coverage of the prostate by the prescription isodose lines compared with our previous technique, as indicated by post-implant dosimetry indices such as V(100), V(90), D(90). The CI was also improved significantly with the protocol guidelines. Our data confirms the validity of the RTOG 98-05 implant guidelines for pre-implant planning as it relates to enlargement of the CTV to ensure adequate margin between the CTV and the prescription isodose lines.

Adult↗

Modifying the American Society for Therapeutic Radiology and Oncology definition of biochemical failure to minimize the influence of backdating in patients with prostate cancer treated with 3-dimensional conformal radiation therapy alone.

PURPOSE: Adoption of the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition has been critical for evaluating and comparing outcome following treatment with radiation. However, since its almost universal adoption, several points have remained controversial, notably backdating the date of failure to the point midway between the posttreatment prostate specific antigen (PSA) nadir and the first increase. We evaluated the impact of backdating on no biochemical evidence of disease (bNED) control and suggest changes in the definition. MATERIALS AND METHODS: Between April 1, 1989 and November 30, 1998, 1,017 patients with nonmetastatic prostate cancer were treated with 3-dimensional conformal radiation therapy alone. bNED control was defined using the ASTRO consensus definition. bNED failure was calculated from the time midway between the posttreatment PSA nadir and the first of the 3 consecutive increases in PSA (date of failure A). Four alternate failure time points were chosen, including backdating to the date of the first increase in PSA after the nadir, the date between the first and second consecutive PSA increases, the date between the second and third consecutive PSA increases, and the date of the third increase in PSA after the nadir (dates of failure 1 to 4). Kaplan-Meier estimates were calculated for all definitions of failure as well as hazard functions with time. Subset analyses based on prognostic group and followup time were also performed. RESULTS: The 10-year Kaplan-Meier bNED control rates were 64%, 52%, 47%, 42% and 39% using dates of failure A and 1 to 4, respectively. These differences persisted when patients were stratified by prognostic group. These same differences in bNED control were observed for the long-term followup subset, in which 10-year bNED control rates were 48%, 47%, 44%, 41% and 39% using dates of failure A and 1 to 4, respectively. CONCLUSIONS: Adoption of the ASTRO consensus definition has been crucial for evaluating outcome in the radiation oncology community. However, the date of failure should be moved from the current point to one closer to the point at which failure is declared. Additional analysis with large numbers of patients from multiple institutions is necessary to determine the point.

Adult↗

Dose response in prostate cancer with 8-12 years' follow-up.

PURPOSE: This communication reports the long-term results of the original group of prostate cancer patients who participated in the first prospective Fox Chase Cancer Center radiation dose escalation study for which 8-12 years of follow-up is now available. METHODS AND MATERIALS: Between March 1, 1989 and October 31, 1992, 232 patients with clinically localized prostate cancer received three-dimensional conformal radiotherapy only at Fox Chase Cancer Center in a prospective dose-escalation study. Of these patients, 229 were assessable. The 8-, 10-, and 12-year actuarial rates of biochemical control (biochemically no evidence of disease [bNED]), freedom from distant metastasis (FDM), and morbidity were calculated. The Cox proportional hazards model was used to assess multivariately the predictors of bNED control and FDM, including pretreatment prostate-specific antigen (PSA) level (continuous), tumor stage (T1/T2a vs. T2b/T3), Gleason score (2-6 vs. 7-10), and radiation dose (continuous). The median total dose for all patients was 74 Gy (range 67-81). The median follow-up for living patients was 110 months (range 89-147). bNED control was defined using the American Society for Therapeutic Radiology and Oncology consensus definition. RESULTS: The actuarial bNED control for all patients included in this series was 55% at 5 years, 48% at 10 years, and 48% at 12 years. Patients with pretreatment PSA levels of 10-20 ng/mL had statistically significant differences (19% vs. 31% vs. 84%, p = 0.0003) in bNED control when stratified by dose (<71.5, 71.5-75.6, and > 75.6 Gy, respectively) on univariate analysis. For the 229 patients with follow-up, 124 (54%) were clinically and biochemically without evidence of disease. Sixty-nine patients were alive at the time of last follow-up, and 55 patients were dead of intercurrent disease. On multivariate analysis, radiation dose was a statistically significant predictor of bNED control for all patients and for unfavorable patients with a pretreatment PSA <10 ng/mL. For the patients with a pretreatment PSA level of 10-20 ng/mL, the radiation dose was a statistically significant predictor across all groups. No radiation dose response was seen for those patients with a pretreatment PSA level >20 ng/mL, although large numbers of patients are required to demonstrate a difference. The radiation dose, Gleason score, and palpation T stage were significant predictors for the entire patient set, as well as for those with pretreatment PSA levels between 10 and 20 ng/mL. The FDM rate for all patients included in this series was 89%, 83%, and 83% at 5, 10, and 12 years, respectively. For patients with pretreatment PSA levels <10 ng/mL, all four covariates (radiation dose, Gleason score, pretreatment PSA, and palpation T stage) were significant predictors of distance metastasis. Using the Radiation Therapy Oncology Group morbidity scale, no difference was noted in the frequency of Grade 2 and 3 genitourinary and Grade 3 gastrointestinal morbidity when patients in this data set were stratified by radiation dose. However, a significant increase occurred in Grade 2 gastrointestinal complications as the radiation dose increased. CONCLUSION: The long-term results of the original Fox Chase radiation dose escalation study with >9 years of median follow-up confirm the existence of a dose response for both bNED control and FDM. The dose response in prostate cancer is real, and the absence of biochemical recurrence after 8 years demonstrates the lack of late failure and suggests cure.

Actuarial Analysis↗

Measurement of intrafractional prostate motion using magnetic resonance imaging.

PURPOSE: To quantify the three-dimensional intrafractional prostate motion over typical treatment time intervals with cine-magnetic resonance imaging (cine MRI) studies. METHODS AND MATERIALS: Forty-two patients with prostate cancer were scanned supine in an alpha cradle cast using cine MRI. Twenty sequential slices were acquired in the sagittal and axial planes through the center of the prostate. Each scan took approximately 9 min. The posterior, lateral, and superior edges of the prostate were tracked on each frame relative to the initial prostate position, and the size and duration of each displacement was recorded. RESULTS: The prostate displacements were (mean +/- SD): 0.2 +/- 2.9 mm, 0.0 +/- 3.4 mm, and 0.0 +/- 1.5 mm in the anterior-posterior, superior-inferior, and medial-lateral dimensions respectively. The prostate motion appeared to have been driven by peristalsis in the rectum. Large displacements of the prostate (up to 1.2 cm) moved the prostate both anteriorly and superiorly and in some cases compressed the organ. For such motions, the prostate did not stay displaced, but moved back to its original position. To account for the dosimetric consequences of the motion, we also calculated the time-averaged displacement to be approximately 1 mm. CONCLUSIONS: Cine MRI can be used to measure intrafractional prostate motion. Although intrafractional prostate motions occur, their effects are negligible compared to interfractional motion and setup error. No adjustment in margin is necessary for three-dimensional conformal or intensity-modulated radiation therapy.

Humans↗

Patterns of Care Study quantitative evaluation of the quality of radiotherapy in Japan.

BACKGROUND: Quality assurance (QA) of clinical practice is important for any medical specialty. Programs based on the Patterns of Care Study (PCS) have been developed to compare the quality of radiotherapeutic care at individual institutions, with the national average representing the process and outcome of radiotherapy. The feasibility of these programs was analyzed. METHODS: Calculation programs for the national average and standard score were developed to evaluate quantitatively the process and outcome of radiotherapy at individual institutions as well as at the national level. The programs were used to evaluate the quality of radiotherapy for 561 esophageal carcinoma patients surveyed in the Japanese PCS. RESULTS: As a representative example of QA measurement, the national average for the 5-year survival rate for these patients in the nonsurgery group was 5%. The regional averages for those in academic and nonacademic institutions were 9% and 1%, respectively (P = 0.0142), showing a significant difference between these two institutional strata. The standard score compared with the national average for institution No.105, for example, was 16.3 (P < 0.0001), with the positive value indicating that the outcome at this institution was significantly higher than the national average. The corresponding figure compared with the regional average was -0.3 (P = 0.7391), with the negative value indicating the outcome is not superior to the regional average of academic institutions. CONCLUSIONS: These programs make it possible to compare quantitatively the quality of radiation therapy at individual institutions with the national and regional averages. They should also be useful for nationwide QA projects in radiation oncology as well as in other medical specialities.

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