Anatomic boundaries of the clinical target volume (prostate bed) after radical prostatectomy

Adjuvant radiotherapy following radical prostatectomy for prostate cancer

BACKGROUND

Men who have a radical prostatectomy (RP) for prostate cancer that does not involve lymph nodes, but extends beyond the prostate capsule into the seminal vesicles or to surgical margins, are at increased risk of relapse. In men with these high risk factors, radiotherapy (RT) directed at the prostate bed after surgery may reduce this risk, and be curative.

OBJECTIVES

To evaluate the effect of adjuvant RT following RP for prostate cancer in men with high risk features compared with RP.

SEARCH METHODS

We searched the Cochrane Prostatic Diseases and Urological Cancers Specialised Register (23 February 2011), the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE (January 1966 to February 2011), PDQ® (Physician Data Query) trial registry databases for ongoing studies (2 November 2010), reference lists from selected studies and reviews, and handsearched relevant conference proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing RP followed by RT with RP alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion and bias and extracted data for analysis. Authors were contacted to clarify data and obtain missing information.

MAIN RESULTS

We found three RCTs involving 1815 men. Adjuvant RT following prostatectomy did not affect overall survival at 5 years (RD (risk difference) 0.00; 95% CI -0.03 to 0.03), but improved survival at 10 years (RD -0.11; 95% CI -0.20 to -0.02). Adjuvant RT did not improve prostate cancer-specific mortality at 5 years (RD -0.01; 95% CI -0.03 to 0.00). Adjuvant RT did not reduce metastatic disease at 5 years (RD -0.00; 95% CI -0.04 to 0.03), but reduced it at 10 years (RD -0.11; 95% CI -0.20 to -0.01). It improved local control at 5 and 10 years (RD -0.10; 95% CI -0.13 to -0.06 and RD -0.14; 95% CI -0.21 to -0.07, respectively), and biochemical progression-free survival at 5 years and 10 years (RD -0.16; 95% CI -0.21 to -0.11 and RD -0.29; 95% CI -0.39 to -0.19, respectively). There were no data for clinical disease-free survival. Adjuvant RT increased acute and late gastrointestinal toxicity [do you have the rd for this?], urinary stricture (RD 0.05; 95% CI 0.01 to 0.09) and incontinence (RD 0.04; 95% CI 0.01 to 0.08). It did not increase erectile dysfunction or degrade quality of life (RD 0.01; 95% CI -0.06 to -0.26), but with limited data.

AUTHORS' CONCLUSIONS

Adjuvant RT after RP improves overall survival and reduces the rate of distant metastases, but these effects are only evident with longer follow up. At 5 and 10 years it improves local control and reduces the risk of biochemical failure, although the latter is not a clinical endpoint. Moderate or severe acute and late toxicity is minimal. There is an increased risk of urinary stricture and incontinence, but no detriment to quality of life, based on limited data. Given that the majority of men who have undergone a RP have a longer life expectancy, radiotherapy should be considered for those with high-risk features following radical prostatectomy. The optimal timing is unclear.

Postprostatectomy radiation therapy: an evidence-based review

While the majority of men with localized prostate cancer who undergo a radical prostatectomy will remain disease free, men with certain clinical and pathological features are known to be at an increased risk for developing a biochemical recurrence and, ultimately, distant metastatic disease. The optimal management of these patients continues to be a source of controversy. To date, three randomized Phase III trials have demonstrated that adjuvant radiation therapy (ART) for patients with certain adverse pathological features results in an improvement in several clinically-relevant end points, including biochemical recurrence-free survival and overall survival. Despite the evidence from these trials showing a benefit for ART, many believe that ART results in overtreatment and unwarranted treatment morbidity for a significant number of patients. Many physicians, therefore, instead advocate for close observation followed by early salvage radiation therapy (SRT) at the time of a biochemical recurrence. The purpose of this review is to evaluate the evidence for and to distinguish between ART and early SRT. We will also highlight current and future areas of research for this patient population, including radiation treatment dose escalation, hypofractionation and androgen deprivation therapy. We will also discuss the cost–effectiveness of ART and early SRT.

Technology assessment of automated atlas based segmentation in prostate bed contouring

Background

Prostate bed (PB) contouring is time consuming and associated with inter-observer variability. We evaluated an automated atlas-based segmentation (AABS) engine in its potential to reduce contouring time and inter-observer variability.

Methods

An atlas builder (AB) manually contoured the prostate bed, rectum, left femoral head (LFH), right femoral head (RFH), bladder, and penile bulb of 75 post-prostatectomy cases to create an atlas according to the recent RTOG guidelines. 5 other Radiation Oncologists (RO) and the AABS contoured 5 new cases. A STAPLE contour for each of the 5 patients was generated. All contours were anonymized and sent back to the 5 RO to be edited as clinically necessary. All contouring times were recorded. The dice similarity coefficient (DSC) was used to evaluate the unedited- and edited- AABS and inter-observer variability among the RO. Descriptive statistics, paired t-tests and a Pearson correlation were performed. ANOVA analysis using logit transformations of DSC values was calculated to assess inter-observer variability.

Results

The mean time for manual contours and AABS was 17.5- and 14.1 minutes respectively (p = 0.003). The DSC results (mean, SD) for the comparison of the unedited-AABS versus STAPLE contours for the PB (0.48, 0.17), bladder (0.67, 0.19), LFH (0.92, 0.01), RFH (0.92, 0.01), penile bulb (0.33, 0.25) and rectum (0.59, 0.11). The DSC results (mean, SD) for the comparison of the edited-AABS versus STAPLE contours for the PB (0.67, 0.19), bladder (0.88, 0.13), LFH (0.93, 0.01), RFH (0.92, 0.01), penile bulb (0.54, 0.21) and rectum (0.78, 0.12). The DSC results (mean, SD) for the comparison of the edited-AABS versus the expert panel for the PB (0.47, 0.16), bladder (0.67, 0.18), LFH (0.83, 0.18), RFH (0.83, 0.17), penile bulb (0.31, 0.23) and rectum (0.58, 0.09). The DSC results (mean, SD) for the comparison of the STAPLE contours and the 5 RO are PB (0.78, 0.15), bladder (0.96, 0.02), left femoral head (0.87, 0.19), right femoral head (0.87, 0.19), penile bulb (0.70, 0.17) and the rectum (0.89, 0.06). The ANOVA analysis suggests inter-observer variability among at least one of the 5 RO (p value = 0.002).

Conclusion

The AABS tool results in a time savings, and when used to generate auto-contours for the femoral heads, bladder and rectum had superior to good spatial overlap. However, the generated auto-contours for the prostate bed and penile bulb need improvement.

Image-guided radiotherapy using surgical clips as fiducial markers after prostatectomy: a report of total setup error, required PTV expansion, and dosimetric implications

PURPOSE

To determine the total setup error and the required planning target volume (PTV) margin for prostate bed without image guided radiotherapy (IGRT), and to demonstrate the feasibility and dosimetric benefit of IGRT post prostatectomy using surgical clips.

MATERIALS AND METHODS

Seventeen patients were treated with intensity modulated radiotherapy (IMRT) to the prostate bed with a 1cm PTV margin. Three-dimensional shifts of the surgical clips inside the prostate bed were measured with respect to the isocenter from 364 orthogonal kV image pairs, and the total setup error was calculated to determine the required PTV margin. Alternative IMRT plans using 5mm or 1cm PTV expansion were generated and compared for rectal and bladder sparing.

RESULTS

Surgical clips were reproducibly and reliably identified. The mean (standard deviation) shifts in the left-right (LR), superior-inferior (SI), and anterior-posterior (AP), axes were: -0.1 mm (1.7 mm), 0.6 mm (2.4 mm), and -2.1 mm (2.6 mm), respectively. The required PTV margins were calculated to be 6, 8, and 9 mm in the LR, AP, and SI axis, respectively. A PTV expansion of 5mm, compared to 1cm, significantly reduced V65 Gy to the rectum by 10%.

CONCLUSIONS

In the absence of IGRT, a non-uniform PTV margin of 6mm LR, 8mm AP, and 9 mm SI should be considered. Use of clips as fiducial markers can decrease the total setup error, enable a smaller PTV margin, and improve rectal sparing.

Endorectal balloon reduces anorectal doses in post-prostatectomy intensity-modulated radiotherapy

BACKGROUND AND PURPOSE

To investigate the effect of an endorectal balloon (ERB) on anal wall (Awall) and rectal wall (Rwall) doses in high-dose post-prostatectomy intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

For 20 patients, referred for salvage IMRT after prostatectomy for prostate cancer, two planning CT-scans were performed: one with and one without an air-filled ERB. A planning target volume (PTV) was defined, using international guidelines. Furthermore, the Awall and Rwall were delineated. In both the scans, IMRT plans were generated with a prescribed dose of 70 Gy. The mean dose (D(mean)), maximum dose, minimum dose, and volumes exposed to doses ranging from ≥ 20 to ≥ 70 Gy (V(20)-V(70)) to the Awall and Rwall were calculated. Finally, inner Rwall surface areas exposed to doses ranging from ≥ 20 to ≥ 70 Gy (A(20)-A(70)) were calculated. Dose-parameters were compared between plans with and without ERB.

RESULTS

All Awall parameters, except V(70), were significantly reduced by the ERB with an overall D(mean) reduction of 6 Gy. Absolute reductions in dose-volume parameters varied from 5% to 11%. Significantly reduced Rwall V(30), V(40), and A(40) were observed with ERB, irrespective of the target volume size.

CONCLUSION

ERB application significantly reduces Awall and to a lesser degree Rwall doses in high-dose post-prostatectomy IMRT.

Treatment-related toxicity and symptom-related bother following postoperative radiotherapy for prostate cancer

INTRODUCTION

Patients have reported late effects and symptom-related bother following postoperative radiotherapy for prostate cancer.

METHODS

Patients treated with postoperative radiotherapy were surveyed at a median 56 months after radiotherapy using the Prostate Cancer Radiation Therapy instrument. A retrospective review was undertaken to obtain Radiation Therapy Oncology Group-Late Effects Normal Tissue (RTOG-LENT) toxicity scores at baseline and during follow-up.

RESULTS

Survey response was 64.5%. Median prostate bed radiation dose was 66 Gy given at a median 14 months after surgery. Adjuvant hormone therapy was given for 2 to 3 years to 40 patients; 22 received salvage therapy. PCRT impairment subscales were reported as mild for gastrointestinal dysfunction, moderate for genitourinary dysfunction and marked for sexual dysfunction. The use of one or more incontinence pads daily was reported by 25.6% and was similar to 23% use reported at baseline. Frequent or worse urinary frequency or hematuria was reported by 4.8%, and by 8.4% of respondents for bowel dysfunction. Moderate to severe disruption from bowel and bladder dysfunction was reported by up to 5.4% and 2.4% of respondents, respectively. Erectile function was described as poor to none in 88.3% of respondents, and dissatisfaction with sexual functioning was reported by 42.7%. Counselling or treatment was offered to 59% of those followed.

CONCLUSION

Combined surgery and postoperative radiotherapy are associated with low and moderate rates of bowel and bladder dysfunction respectively, with low reported bother. High levels of sexual dysfunction and bother are seen following combined therapy. More effective pre- and post-treatment counselling are required, along with research into more effective prevention and treatment strategies.

Salvage radiotherapy following biochemical relapse after radical prostatectomy: proceedings of the Genito-Urinary Radiation Oncologists of Canada consensus meeting

For patients with recurrent prostate cancer after radical prostatectomy, salvage radiotherapy is the only potentially curative treatment option. However, until recently there has been a paucity of data on the effectiveness of this approach. In light of recently published studies, the Genito-Urinary Radiation Oncologists of Canada (GUROC) met and crafted a consensus statement regarding the current place of salvage radiotherapy. GUROC also identified gaps in current knowledge and identified ongoing study protocols that will advance our knowledge in this area.This report summarizes the main conclusions of the meeting and the commentary provided during the consensus-building process, and outlines the consensus statement that was subsequently adopted.

Anatomic differences after robotic-assisted radical prostatectomy and open prostatectomy: implications for radiation field design

PURPOSE

To investigate the anatomy of the pelvis following robotic-assisted radical prostatectomy (RARP) compared to the anatomy of the pelvis following open prostatectomy (OP), and to determine if postoperative radiation field design should take surgical approach into consideration.

METHODS AND MATERIALS

This report is a retrospective review of the postoperative pelvic magnetic resonance imaging (MRI) scans for all OP patients (10) and all RARP patients (15) who presented consecutively to the radiation oncology clinic and subsequently underwent MRI scanning between January 2007 and December 2008. All patients who presented are included in the study. We measured 13 distinct anatomic distances, and we used t tests to examine mean differences in each of the parameters between RARP and OP and analysis of variance to examine mean differences controlling for length of follow-up MRI postsurgery (in days) and body mass index as covariates.

RESULTS

Of the measurements, we found that the superior levator separation is statistically significantly greater in the post-RARP group than in the post-OP group (P < .01). Similarly, the post-RARP group had a greater mean resection defect measurement (P = .01) as measured by a larger width of the bladder infundibulum. This suggests that the size of trigonal musculature defect is more pronounced after RARP. The total urethral length was statistically significantly longer in the RARP group (P = .03). The vesicorectal distance was variable depending on the location along the rectal wall but trended toward larger separation in the post-RARP group (P = .05).

CONCLUSIONS

The pelvic anatomy after RARP is considerably different from that after OP. The current standard field design for post-prostatectomy radiation is defined by the post-OP pelvis. Our data support that the clinical target volume borders be expanded posteriorly and laterally in men who have undergone RARP. As RARP continues to become a more widespread surgical option for the management of localized prostate cancer, radiation field design may need to be adjusted.

Magnetic resonance imaging in postprostatectomy radiotherapy planning

PURPOSE

To investigate whether the use of magnetic resonance imaging (MRI) in prostate bed treatment planning could influence definition of the clinical target volume (CTV) and organs at risk.

METHODS AND MATERIALS

A total of 21 consecutive patients referred for prostate bed radiotherapy were included in the present retrospective study. The CTV was delineated according to the European Organization for Research and Treatment of Cancer recommendations on computed tomography (CT) and T(1)-weighted (T(1)w) and T(2)-weighted (T(2)w) MRI. The CTV magnitude, agreement, and spatial differences were evaluated on the planning CT scan after registration with the MRI scans.

RESULTS

The CTV was significantly reduced on the T(1)w and T(2)w MRI scans (13% and 9%, respectively) compared with the CT scans. The urinary bladder was drawn smaller on the CT scans and the rectum was smaller on the MRI scans. On T(1)w MRI, the rectum and urinary bladder were delineated larger than on T(2)w MRI. Minimal agreement was observed between the CT and T(2)w images. The main spatial differences were measured in the superior and superolateral directions in which the CTV on the MRI scans was 1.8-2.9 mm smaller. In the posterior and inferior border, no difference was seen between the CT and T(1)w MRI scans. On the T(2)w MRI scans, the CTV was larger in these directions (by 1.3 and 1.7 mm, respectively).

CONCLUSIONS

The use of MRI in postprostatectomy radiotherapy planning resulted in a reduction of the CTV. The main differences were found in the superior part of the prostate bed. We believe T(2)w MRI enables more precise definition of prostate bed CTV than conventional planning CT.

Prospective development of an individualised predictive model for treatment coverage using offline cone beam computed tomography surrogate measures in post-prostatectomy radiotherapy

The aim of this study is to prospectively evaluate and model surrogate explanatory variables (SEVs) of target coverage and rectal dose pertaining to soft tissue anatomy visualised on cone beam computed tomography (CBCT) for incorporation into post-prostatectomy treatment coverage verification protocols. Twenty post-prostatectomy patients treated with conformal prostate bed radiotherapy (64-74 Gy) underwent CBCT daily at fractions 1 to 5, and then weekly. Treatment coverage was defined on each CBCT using 'PTV95', percentage of the CBCT PTV covered by original treatment fields, and 'RECTD50', dose delivered to 50% of CBCT rectal volume by original treatment fields. Three candidate SEVs for treatment coverage were defined for each scan: anterior rectal wall movement, change in bladder length and bladder base movement. Both anterior rectal wall movement and increase in bladder length predicted for the decreased PTV95 (P < 0.001 for each). Anterior movement of the anterior rectal wall predicted for increased RECTD50 (P < 0.001). Predictive models for the PTV95 and RECTD50 that accept the significant SEVs as inputs were developed. We developed simple CBCT-acquired soft tissue anatomic surrogate measures that signal changes in target coverage and rectal dose during post-prostatectomy radiotherapy. Conventional bony anatomy patient position verification protocols were inadequate in accounting for soft tissue target and organ variation seen with CBCT.

Transperitoneal laparoscopic prostatectomy does not increase small bowel within the target volume for postoperative radiotherapy

PURPOSE

Laparoscopic or robot assisted laparoscopic radical prostatectomy is often performed via a transperitoneal approach for prostate cancer, in contrast to open retropubic radical prostatectomy. Theoretically transgressing the peritoneum may introduce small bowel loops into the pelvis, increasing the risk of small bowel injury with adjuvant radiotherapy. We compared the incidence of small bowel within the planning target volume for radiotherapy to the prostate bed in patients who underwent open retropubic and laparoscopic radical prostatectomy.

MATERIALS AND METHODS

A total of 25 patients recently treated with laparoscopic radical prostatectomy prospectively provided consent to undergo radiotherapy planning computerized tomography simulation to assess the incidence of small bowel within the prostate bed planning target volume. These studies were compared to radiotherapy planning computerized tomography in 50 patients who underwent open retropubic radical prostatectomy and received adjuvant or salvage radiotherapy for prostate cancer. For all computerized tomography images 1 blinded observer delineated the distal small bowel loops and 1 blinded radiation oncologist delineated the superior extent of clinical and planning target volumes.

RESULTS

The overlap rate between small bowel and planning target volume was 16% in the laparoscopic and open radical prostatectomy groups (p = 0.579).

CONCLUSIONS

There is no difference between transperitoneal laparoscopic and open retropubic radical prostatectomy in the incidence of small bowel within the planning target volume for radiotherapy to the prostate bed. Thus, patients who undergo transperitoneal laparoscopic radical prostatectomy do not face a higher risk of toxicity or compromise due to adjuvant or salvage radiotherapy should they require it.

Verification of target position in the post-prostatectomy cancer patient using cone beam CT

We present the results of a pilot study designed to investigate methods that may be applied to develop a patient position correction protocol for the post-prostatectomy patient receiving radiotherapy. Imaging was carried out with cone beam CT (CBCT) to investigate its suitability for detecting changes in rectal and bladder volumes and movements of these organs relative to the treatment planning CT. Eligible patients were imaged daily during the first week of treatment and weekly thereafter. Surrogate explanatory variables, including distance from the isocentre to the anterior rectum and bladder length, were tested for their potential to substitute for contouring entire organs and predict for changes in coverage of the planning treatment volume (PTV) by the 95% isodose (PTV95) and the maximum dose delivered to 50% of the rectal volume (RECTD50). The PTV defined on the CBCT images was larger than that defined on the planning CT and resulted in a decrease in the PTV95. Bladder length correlated with bladder volume and changes in bladder volume were associated with a decrease in PTV95. Rectal volumes changed randomly during treatment. There was a trend for the rectum to move anteriorly as treatment progressed. CBCT may be used to define the PTV, rectum and bladder though the reason for an apparent increase in PTV on CBCT requires further investigation. The bladder length and distance to the anterior rectal wall are potential surrogate explanatory variables. Further studies will be designed to test values of these surrogates that predict the need for a change in isocentre position.

[Which imaging methods should be used prior to salvage radiotherapy after prostatectomy for prostate cancer?]

Prostatectomy is one of the most widely used methods for treatment of adenocarcinoma of the prostate. According to anatomopathological criteria, between 10 and 40% of patients will display biochemical relapse in the absence of adjuvant radiotherapy. Anatomopathological and biochemical criteria are powerful tools for selecting patients for salvage radiotherapy. The aim of this article is to review literature on the latest progress in radiological and nuclear medicine techniques and their performance levels, in order to determine local, regional and metastatic relapses associated with the techniques and specify the radiotherapy target volume. Magnetic resonance imaging (MRI) displays the best sensitivity and specificity for examination of the prostate bed and enables simultaneous assessment of the pelvic region - thus diminishing the utility of computed tomography. The performance levels of MRI will probably continue to improve, with the use of dynamic MRI and MR spectroscopy. Despite the development of new markers like (11)C and (18)F choline and acetate, the sensitivity of positron emission tomography is still low. Prospective studies with an appropriate methodology are necessary for specifying the technique's value in this context.

Development of RTOG consensus guidelines for the definition of the clinical target volume for postoperative conformal radiation therapy for prostate cancer

PURPOSE

To define a prostate fossa clinical target volume (PF-CTV) for Radiation Therapy Oncology Group (RTOG) trials using postoperative radiotherapy for prostate cancer.

METHODS AND MATERIALS

An RTOG-sponsored meeting was held to define an appropriate PF-CTV after radical prostatectomy. Data were presented describing radiographic failure patterns after surgery. Target volumes used in previous trials were reviewed. Using contours independently submitted by 13 radiation oncologists, a statistical imputation method derived a preliminary "consensus" PF-CTV.

RESULTS

Starting from the model-derived CTV, consensus was reached for a CT image-based PF-CTV. The PF-CTV should extend superiorly from the level of the caudal vas deferens remnant to >8-12 mm inferior to vesicourethral anastomosis (VUA). Below the superior border of the pubic symphysis, the anterior border extends to the posterior aspect of the pubis and posteriorly to the rectum, where it may be concave at the level of the VUA. At this level, the lateral border extends to the levator ani. Above the pubic symphysis, the anterior border should encompass the posterior 1-2 cm of the bladder wall; posteriorly, it is bounded by the mesorectal fascia. At this level, the lateral border is the sacrorectogenitopubic fascia. Seminal vesicle remnants, if present, should be included in the CTV if there is pathologic evidence of their involvement.

CONCLUSIONS

Consensus on postoperative PF-CTV for RT after prostatectomy was reached and is available as a CT image atlas on the RTOG website. This will allow uniformity in defining PF-CTV for clinical trials that include postprostatectomy RT.

Assessing the effect of a contouring protocol on postprostatectomy radiotherapy clinical target volumes and interphysician variation

PURPOSE

To compare postprostatectomy clinical target volume (CTV) delineation before and after the introduction of a contouring protocol and to investigate its effect on interphysician variability

METHODS AND MATERIALS

Six site-specialized radiation oncologists independently delineated a CTV on the computed tomography (CT) scans of 3 patients who had received postprostatectomy radiotherapy. At least 3 weeks later this was repeated, but with the physicians adhering to the contouring protocol from the Medical Research Council's Radiotherapy and Androgen Deprivation In Combination After Local Surgery (RADICALS) trial. The volumes obtained before and after the protocol were compared and the effect of the protocol on interphysician variability assessed.

RESULTS

An increase in mean CTV for all patients of 40.7 to 53.9 cm(3) was noted as a result of observing the protocol, with individual increases in the mean CTV of 65%, 15%, and 24% for Patients 1, 2, and 3 respectively. A reduction in interphysician variability was noted when the protocol was used.

CONCLUSIONS

Substantial interphysician variation in target volume delineation for postprostatectomy radiotherapy exists, which can be reduced by the use of a contouring protocol. The RADICALS contouring protocol increases the target volumes when compared with those volumes typically applied at our center. The effect of treating larger volumes on the therapeutic ratio and resultant toxicity should be carefully monitored, particularly if the same dose-response as documented in radical prostate radiotherapy applies to the adjuvant and salvage setting. Prostate cancer, Postprostatectomy, Radiotherapy, Target volume.

Adjuvant and salvage radiotherapy after prostatectomy for prostate cancer: a literature review

PURPOSE

Given that postprostatectomy recurrence of prostate cancer occurs in 10-40% of patients, the best use of immediate postoperative radiotherapy (RT) in high-risk patients and salvage RT for biochemical recurrence remains a topic of debate. We assessed the levels of evidence (in terms of efficacy, prognostic factors, and toxicity) for the following treatment strategies: immediate postoperative RT alone, salvage RT alone, and the addition of androgen deprivation therapy to the two RT strategies.

METHODS AND MATERIALS

A systematic literature search for controlled randomized trials, noncontrolled trials, and retrospective studies between 1990 and 2008 was performed on PubMed, CancerLit, and MEDLINE. Only relevant articles that had appeared in peer-reviewed journals were selected. We report on the levels of evidence (according to the National Cancer Institute guidelines) supporting the various treatment strategies.

RESULTS

Immediate postoperative RT improves biochemical and clinical progression-free survival (Level of evidence, 1.ii) but has no significant effect on metastasis-free survival or overall survival. A pathologic review is of particular importance for correctly analyzing the treatment strategies. Low-grade morbidity has been significantly greater in the postoperative groups, but no severe toxicity has been observed. The influence of immediate postoperative RT on postprostatectomy continence appears to be slight; therefore, immediate postoperative RT should be considered in patients with major risk factors for local relapse (Level of evidence, 1.ii). On the basis of extensive retrospective data, salvage RT is effective in biochemical relapse after prostatectomy; some patients with few adverse prognostic factors might also benefit from salvage RT (Level of evidence, 3.ii). The addition of androgen deprivation therapy to immediate postoperative or salvage RT has only been supported by weak, retrospective data (Level of evidence, 3.ii).

CONCLUSION

Prospective randomized trials are needed to compare immediate postoperative RT with salvage RT and to assess the value of androgen deprivation therapy in this setting.

Adjuvant radiotherapy following radical prostatectomy for pathologic T3 or margin-positive prostate cancer: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Results following radical prostatectomy (RP) are suboptimal in patients found to have cancer extending beyond the prostatic capsule (pT3) or present at the resection margins (R1). The optimal postoperative management of such patients is undefined. Therapeutic alternatives include adjuvant radiotherapy (RT) or active surveillance.

METHODS

Randomized controlled trials (RCTs) were eligible for inclusion in this systematic review if they compared adjuvant RT in the immediate period after RP to active surveillance - with therapies held in reserve for salvage - in prostate cancer patients with pT3 or R1 disease or both. The primary outcome of interest was overall survival.

RESULTS

Three RCTs representing 1,743 patients satisfied the eligibility criteria. Two trials reported data on overall survival; a meta-analysis of the data showed no significant improvement associated with adjuvant RT (hazard ratio=0.91, 95% CI 0.67-1.22, p=0.52). All trials reported data on biochemical progression-free survival (bPFS). On meta-analysis, adjuvant RT significantly improved bPFS (hazard ratio=0.47, 95% CI 0.40-0.56, p<0.00001). One trial provided comparative graded toxicity data; there were no significant differences between arms in severe (grade 3) gastrointestinal or genitourinary toxicity at five years.

CONCLUSIONS

To date, adjuvant RT has not been shown to improve overall survival compared with active surveillance. Longer follow-up from completed RCTs is required to accurately assess this outcome. Adjuvant RT does, however, significantly improve bPFS and is not associated with excess severe late toxicity.