Gerard Morton

Feasibility study : watchful waiting for localized low to intermediate grade prostate carcinoma with selective delayed intervention based on prostate specific antigen, histological and/or clinical progression

PURPOSE We assessed the feasibility of a watchful waiting protocol with selective delayed intervention using clinical, prostate specific antigen (PSA) or histological progression as treatment indications for clinically localized prostate cancer. MATERIALS AND METHODS In this prospective, single arm cohort study patients with favorable clinical parameters (stage T1b to T2b N0M0, Gleason score 7 or less and PSA 15 ng./ml. or less) are conservatively treated with watchful waiting. When a patient meets disease progression criteria, arbitrarily defined by the 3 parameters of the rate of PSA increase, clinical progression or histological upgrade on repeat prostate biopsy, appropriate treatment is implemented. Patients are followed every 3 months for the first 2 years and every 6 months thereafter. Serum PSA measurement and digital rectal examination are done at each visit and repeat prostate biopsy is performed 18 months after study enrollment. RESULTS Since November 1995, the study has accrued 206 patients with a median followup of 29 months (range 2 to 66). Of these men 137 remain on the surveillance protocol with no disease progression, while 69 were withdrawn from study for various reasons. There was clinical, PSA and histological progression in 16, 15 and 5 cases, respectively. The estimated actuarial probability of remaining on the surveillance protocol was 67% at 2 years and 48% at 4. The probability of remaining progression-free was 81% and 67% at 2 and 4 years, respectively. CONCLUSIONS A policy of watchful waiting with selectively delayed intervention based on predefined criteria of disease progression is feasible. This strategy offers the benefit of an individualized approach based on the demonstrated risk of clinical or biochemical progression with time and, thus, it may decrease the burden of therapy in patients with indolent disease, while providing definitive therapy for those with biologically active disease.

American Brachytherapy Society consensus guidelines for high-dose-rate prostate brachytherapy.

PURPOSE A well-established body of literature supports the use of high-dose-rate (HDR) brachytherapy as definitive treatment for localized prostate cancer. Most of the articles describe HDR as a boost with adjuvant external beam radiation, but there is a growing experience with HDR monotherapy. METHODS AND MATERIALS The American Brachytherapy Society has convened a group of expert practitioners and physicists to develop guidelines for the use of HDR in the management of prostate cancer. This involved an extensive literature review and input from an expert panel. RESULTS Despite a wide variation in doses and fractionation reported, HDR brachytherapy provides biochemical control rates of 85-100%, 81-100%, and 43-93% for low-, intermediate-, and high-risk prostate cancers, respectively. Severe toxicity is rare, with most authors reporting less than 5% Grade 3 or higher toxicity. Careful attention to patient evaluation for appropriate patient selection, meticulous technique, treatment planning, and delivery are essential for successful treatment. CONCLUSION The clinical outcomes for HDR are excellent, with high rates of biochemical control, even for high-risk disease, with low morbidity. HDR monotherapy, both for primary treatment and salvage, are promising treatment modalities.

Preliminary Toxicity Analysis of 3-Dimensional Conformal Radiation Therapy Versus Intensity Modulated Radiation Therapy on the High-Dose Arm of the Radiation Therapy Oncology Group 0126 Prostate Cancer Trial

PURPOSE To give a preliminary report of clinical and treatment factors associated with toxicity in men receiving high-dose radiation therapy (RT) on a phase 3 dose-escalation trial. METHODS AND MATERIALS The trial was initiated with 3-dimensional conformal RT (3D-CRT) and amended after 1 year to allow intensity modulated RT (IMRT). Patients treated with 3D-CRT received 55.8 Gy to a planning target volume that included the prostate and seminal vesicles, then 23.4 Gy to prostate only. The IMRT patients were treated to the prostate and proximal seminal vesicles to 79.2 Gy. Common Toxicity Criteria, version 2.0, and Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late morbidity scores were used for acute and late effects. RESULTS Of 763 patients randomized to the 79.2-Gy arm of Radiation Therapy Oncology Group 0126 protocol, 748 were eligible and evaluable: 491 and 257 were treated with 3D-CRT and IMRT, respectively. For both bladder and rectum, the volumes receiving 65, 70, and 75 Gy were significantly lower with IMRT (all P<.0001). For grade (G) 2+ acute gastrointestinal/genitourinary (GI/GU) toxicity, both univariate and multivariate analyses showed a statistically significant decrease in G2+ acute collective GI/GU toxicity for IMRT. There were no significant differences with 3D-CRT or IMRT for acute or late G2+ or 3+ GU toxicities. Univariate analysis showed a statistically significant decrease in late G2+ GI toxicity for IMRT (P=.039). On multivariate analysis, IMRT showed a 26% reduction in G2+ late GI toxicity (P=.099). Acute G2+ toxicity was associated with late G3+ toxicity (P=.005). With dose-volume histogram data in the multivariate analysis, RT modality was not significant, whereas white race (P=.001) and rectal V70 ≥15% were associated with G2+ rectal toxicity (P=.034). CONCLUSIONS Intensity modulated RT is associated with a significant reduction in acute G2+ GI/GU toxicity. There is a trend for a clinically meaningful reduction in late G2+ GI toxicity with IMRT. The occurrence of acute GI toxicity and large (>15%) volumes of rectum >70 Gy are associated with late rectal toxicity.

PREVALENCE AND PATTERNS OF THE USE OF COMPLEMENTARY THERAPIES AMONG PROSTATE CANCER PATIENTS: AN EPIDEMIOLOGICAL ANALYSIS

PURPOSE We determine the prevalence and patterns of the use of complementary therapies among patients with and those at high risk for prostate cancer. MATERIALS AND METHODS A cross-sectional survey was performed of men presenting to 2 urban tertiary urology clinics for prostate cancer evaluation or followup, and those attending a prostate cancer support group. All men diagnosed with and those at high risk (positive family history or abnormal prostate specific antigen) for prostate cancer were eligible for study. A 9-item self-administered, anonymous questionnaire about complementary therapies was administered. RESULTS Of 357 patients who received the survey 155 from the urology clinics and 113 from the support group responded, for a total response rate of 75%. Of the patients presenting to urology clinics and the support group 27.4 and 38.9% with and 25.8 and 80% at high risk for prostate cancer, respectively, used some form of complementary therapy. The use significantly differed according to disease status (p = 0.001), and was highest among men who were clinically disease-free after radical therapy. Of the patients 24% did not inform the urologist of using alternative therapy. CONCLUSIONS The prevalence of the use of complementary therapy among patients with or at increased risk for prostate cancer was high and dependent on the disease state. Urologists should be aware of this pattern of use, and consider the potential effects when assessing patients for and with prostate cancer.

Target position variability throughout prostate radiotherapy

PURPOSE To quantify the variability in prostate and seminal vesicle position during a course of external beam radiotherapy, and to measure the proportion of target variability due to setup error. METHODS AND MATERIALS Forty-four weekly planning computerized tomography (CT) studies were obtained on six patients undergoing radiotherapy for prostate cancer. All patients were scanned in the radiotherapy treatment position, supine with an empty bladder, with no immobilization device. All organs were outlined on 3-mm-thick axial CT images. Anterior and lateral beams eye view digitally reconstructed radiographs and multiplanar reformatted images were generated. The position of the prostate and seminal vesicles relative to the isocenter location as set that day was recorded for each CT study. Target position relative to a bony landmark was measured to determine the relative contribution of setup error to the target position variability. RESULTS The seminal vesicle and prostate position variability was most significant in the anterior-posterior (AP) direction, followed by cranial-caudal (CC) and mediolateral (ML) directions. Setup error contributed significantly to the total target position variability. Rectal filling was associated with a trend to anterior movement of the prostate, whereas bladder filling was not associated with any trends. Although most deviations from the target position determined at the initial planning CT scan were within 10 mm, deviations as large as 15 mm and 19 mm were seen in the prostate and seminal vesicles respectively. Target position variations were evenly distributed around the initial target position for some patient studies, but unpredictable patterns were also seen. From a simulation based on the observed variability in target position, the AP, CC, and ML planning target volume (PTV) borders around the clinical target volume (CTV) required for target coverage with 95% certainty are 12.4 mm, 10.3 mm, and 5.6 mm respectively for the prostate and 13.8 mm, 8.6 mm, and 3.9 mm respectively for the seminal vesicles. CONCLUSION Target position variability is significant during prostate radiotherapy, requiring large PTV borders around the CTV. This target position variability may be potentially reduced by improving the setup accuracy.

PSA doubling time of prostate carcinoma managed with watchful observation alone

PURPOSE To study prostate-specific antigen (PSA) doubling time of untreated, favorable grade, prostate carcinoma. METHODS AND MATERIALS A prospective single-arm cohort study has been in progress to assess the feasibility of a watchful observation protocol with selective delayed intervention using clinical, histologic, or PSA progression as treatment indication in untreated, localized, favorable grade prostate adenocarcinoma (T1b-T2bN0 M0, Gleason Score < or = 7, and PSA < or = 15 ng/mL). Patients are conservatively managed with watchful observation alone, as long as they do not meet the arbitrarily defined disease progression criteria. Patients are followed regularly and undergo blood tests including PSA at each visit. PSA doubling time (Td) is estimated from a linear regression of ln(PSA) on time, assuming a simple exponential growth model. RESULTS As of March 2000, 134 patients have been on the study for a minimum of 12 months (median, 24; range, 12-52) and have a median frequency of PSA measurement of 7 times (range, 3-15). Median age is 70 years. Median PSA at enrollment is 6.3 (range, 0.5-14.6). The distribution of Td is as follows: <2 years, 19 patients; 2-5 years, 46; 5-10 years, 25; 10-20 years, 11; 20-50 years, 6; > 50 years, 27. The median Td is 5.1 years. In 44 patients (33%), Td is greater than 10 years. There was no correlation between Td and patient age, clinical T stage, Gleason score, or initial PSA level. CONCLUSION Td of untreated prostate cancer varies widely. In our cohort, 33% have Td > 10 years. Td may be a useful tool to guide treatment intervention for patients managed conservatively with watchful observation alone.

POSITIVE RESECTION MARGIN AND/OR PATHOLOGIC T3 ADENOCARCINOMA OF PROSTATE WITH UNDETECTABLE POSTOPERATIVE PROSTATE-SPECIFIC ANTIGEN AFTER RADICAL PROSTATECTOMY: TO IRRADIATE OR NOT?

PURPOSE To evaluate the efficacy of postoperative adjuvant radiotherapy (RT) for positive resection margin and/or pathologic T3 (pT3) adenocarcinoma of the prostate with undetectable postoperative prostate-specific antigen (PSA) levels. METHODS AND MATERIALS We retrospectively analyzed 125 patients with a positive resection margin and/or pT3 adenocarcinoma of the prostate who had undetectable postoperative serum PSA levels after radical prostatectomy. Seventy-three patients received postoperative adjuvant RT and 52 did not. Follow-up ranged from 1.5 to 12.0 years (median 4.2 for the irradiated group and 4.9 for the nonirradiated group). PSA outcome was available for all patients. Freedom from failure was defined as the maintenance of a serum PSA level of < or =0.2 ng/mL, as well as the absence of clinical local recurrence and distant metastasis. RESULTS No difference was found in the 5-year actuarial overall survival between the irradiated and nonirradiated group (94% vs. 95%). However, patients receiving adjuvant RT had a statistically superior 5-year actuarial relapse-free rate, including freedom from PSA failure, compared with those treated with surgery alone (88% vs. 65%, p = 0.0013). In the irradiated group, 8 patients had relapse with PSA failure alone. None had local or distant recurrence. In the nonirradiated group, 15, 1, and 2 had PSA failure, local recurrence, and distant metastasis, respectively. On Cox regression analysis, pre-radical prostatectomy PSA level and adjuvant RT were statistically significant predictive factors for relapse, and Gleason score, extracapsular invasion, and resection margin status were not. There was a suggestion that seminal vesicle invasion was associated with an increased risk of relapse. The morbidity of postoperative adjuvant RT was acceptable, with only 2 patients developing Radiation Therapy Oncology Group Grade 3 genitourinary complications. Adjuvant RT had a minimal adverse effect on urinary continence and did not cause serious gastrointestinal toxicity. CONCLUSION Postoperative adjuvant RT was associated with a lower risk of relapse, including freedom from PSA failure, compared with observation alone for pT3 and/or margin-positive disease with undetectable postoperative PSA levels. This was accomplished with a minimal risk of serious RT morbidity.

Phase I/II Study of a Five-fraction Hypofractionated Accelerated Radiotherapy Treatment for Low-risk Localised Prostate Cancer: Early Results of pHART3

AIMS Most men with low-risk localised prostate cancer prefer treatments with high control rates and minimal disruption to their lives. Hypofractionating external radiation treatments can theoretically maintain high bioequivalent tumour doses, decrease treatment visits and decrease acute and late toxicities. The aim of this study was to assess the toxicity and feasibility of a hypofractionated accelerated regimen for these patients. MATERIALS AND METHODS The present study was a phase I/II study in which patients with T1-2b, Gleason < or = 6 and prostate-specific antigen (PSA) < or = 10 ng/ml prostate cancer received 35Gy in five fractions, once a week over 29 days. Treatment was delivered with intensity-modulated radiotherapy on standard linear accelerators, with daily image guidance using gold seed fiducials, and a 4mm clinical target volume to planning target volume margin. RESULTS As of January 2008, the target accrual of 30 patients had been reached and all had completed treatment and at least 6 months of follow-up. Dose-volume histogram objectives were achievable in all patients. Treatment was very well tolerated with no grade 3 or 4 genitourinary toxicity, gastrointestinal toxicity nor fatigue observed (95% confidence interval 0-12%). As a group, compared with baseline, the following additional grade 2 toxicities were observed: 13% genitourinary, 7% gastrointestinal and 10% fatigue. At 6 months all scores had returned to or improved over baseline. The median PSA before treatment was 6.0 ng/ml. At 6 months, the median PSA was 1.8 ng/ml and 75% had a PSA < or = 3.0 ng/ml. CONCLUSIONS This novel technique using standard linear accelerators seems feasible and is well tolerated. Further follow-up will be carried out to document late toxicity and efficacy.

(IN)-efficacy of salvage radiotherapy for rising PSA or clinically isolated local recurrence after radical prostatectomy

PURPOSE To determine the efficacy of external beam radiotherapy (RT) as salvage treatment for prostate-specific antigen (PSA) failure or local recurrence after radical prostatectomy. METHODS AND MATERIALS Between 1991 and 1997, 98 patients underwent salvage RT to the prostatic bed at the Toronto Sunnybrook Regional Cancer Centre for PSA failure or local recurrence after radical prostatectomy. Thirty-six patients were treated for persistently detectable postoperative PSA levels (Group A), 26 for a delayed PSA rise (Group B), and 36 for palpable and/or biopsy-proven local recurrence (Group C). None had clinically apparent distant metastasis at the time of salvage RT. Freedom from PSA failure was defined as the maintenance of PSA <or=0.2 ng/mL. Cox regression analyses were performed to identify factors predictive of relapse. RESULTS The median follow-up from radical prostatectomy and RT was 5.11 and 4.21 years for Group A, 5.31 and 3.32 years for Group B, and 7.85 and 3.95 years for Group C, respectively. The initial PSA response rate was encouraging at a range of 86-94%. The complete PSA response rate (PSA <or=0.2 ng/mL) was lower, however and ranged from 53% to 62%. The actuarial relapse-free rate, including freedom from PSA failure, at 4 years was 26%, 39%, and 14% for Groups A, B, and C, respectively. At the time of the last follow-up, 49, 20, and 1 patient had PSA failure alone, distant metastasis, and local progression, respectively. The actuarial survival rate at 4 years was 89%, 95%, and 94% for Groups A, B, and C, respectively. On Cox regression analysis, the significant predictors for relapse were PSA level before salvage RT and Gleason score for Group A, none for Group B, and margin status for Group C. CONCLUSION The efficacy of salvage RT for PSA failure or local recurrence after RT was limited, reflected by very low relapse-free rates. Salvage RT appeared more efficacious for patients with a delayed PSA rise than for those with either persistently detectable postoperative PSA levels or clinically palpable local recurrence. Other strategies such as a combination of salvage RT and hormonal therapy need to be explored.

Is single fraction 15 Gy the preferred high dose-rate brachytherapy boost dose for prostate cancer?

BACKGROUND AND PURPOSE High dose-rate (HDR) brachytherapy is most commonly administered as a boost in two or more fractions combined with external beam radiotherapy (EBRT). Our purpose is to compare outcomes with a single fraction HDR boost to that with a standard fractionated boost in intermediate risk prostate cancer. MATERIALS AND METHODS Results of two sequential phase II clinical trials are compared. The Single Fraction protocol consists of 15 Gy HDR in one fraction followed by 37.5 Gy EBRT in 15 fractions over 3 weeks; the Standard Fractionation protocol consisted of two HDR fractions each of 10 Gy, 1 week apart, followed by 45 Gy EBRT in 25 fractions. Patients had intermediate risk disease, and were well balanced for prognostic factors. Patients were followed prospectively for efficacy, toxicity and health-related quality of life (Expanded Prostate Index Composite). Efficacy was assessed biochemically using the Phoenix definition, and by biopsy at 2 years. RESULTS The Single Fraction protocol accrued 123 patients and the Standard Fractionation protocol, 60. With a median follow-up of 45 and 72 months, respectively, the biochemical disease-free survival was 95.1% and 97.9% in the Single and Standard Fractionation trials (p=0.3528). Two-year prostate biopsy was positive in only 4% and 8%, respectively. There was no difference in late urinary or rectal toxicity rates, or in health-related quality of life between the two protocols. CONCLUSIONS The Single Fraction HDR protocol results in high disease control rate and low toxicity similar to our previous protocol using two HDR insertions, with significant savings in resources. While mature results with longer follow-up are awaited, a single 15 Gy may be considered as a standard fractionation regimen in combination with EBRT for men with intermediate risk disease.