Outcome, morbidity, and prognostic factors in post-prostatectomy radiotherapy: an Australian multicenter study

Post-prostatectomy radiotherapy adversely affects urinary continence irrespective of radiotherapy regime

PURPOSE

To investigate the influence of different postoperative radiotherapy (RT) regimes on post-prostatectomy continence and QoL.

METHODS

Men after prostatectomy (RP) and RT were assigned in adjuvant (ART), early salvage (ESRT) and salvage radiotherapy (SRT) groups depending on time of initiation, indication and pre-RT-PSA (≤/>0.5 ng/ml). Continence and QoL outcomes were evaluated by validated questionnaire. Statistical analysis included students t test, Chi square, Fisher's test, ROC- and McNemar-Bowker-Analyses.

RESULTS

The mean follow-up was 5.1 years. 33.5, 38.2 and 28.3% received ART, ESRT and SRT, respectively. Mean time to RT was 0.3 (±0.4), 1.8 (±2.5) and 3.3 (±3.6) years respectively. Differences in age at RP (p = 0.54) and RT (p = 0.47) between groups were not significant. Mean-RT-dose was similar (p = 0.70). Differences in continence distribution between groups before (p = 0.56) and after RT (p = 0.38) were not significant. No significant differences were observed for frequency (p = 0.58) or amount (p = 0.88) of urine loss, impact on QoL (p = 0.13) and ICIQ-SF scores (p = 0.69) between groups. Even though no significant difference in post-RT-continence (p = 0.89) was observed in the direct comparison between groups, a significant worsening of long-term continence was observed in all groups (p < 0.001). We found no cutoff and no time-point after RP at which this negative effect of RT on continence became insignificant (AUC = 0.474). A subgroup with apparent local recurrence showed no differences for ICIQ-SF-score (p = 0.155), QoL (0.077), incontinence grade (p = 0.387), frequency (p = 0.182) and amount (p = 0.415) of urine loss. Proportionally more men in this subgroup remembered deterioration of continence after RT (p = 0.029).

CONCLUSION

Postoperative RT adversely affects long-term continence; this negative effect is irrespective of time of initiation or indication for RT. These results suggest a need for innovative strategies of prostate cancer therapy with lasting oncological, functional and QoL outcomes.

Toxicity after post-prostatectomy image-guided intensity-modulated radiotherapy using Australian guidelines

INTRODUCTION

We evaluated single institution toxicity outcomes after post-prostatectomy radiotherapy (PPRT) via image-guided intensity-modulated radiation therapy (IG-IMRT) with implanted fiducial markers following national eviQ guidelines, for which late toxicity outcomes have not been published.

METHODS

Prospectively collected toxicity data were retrospectively reviewed for 293 men who underwent 64-66 Gy IG-IMRT to the prostate bed between 2007 and 2015.

RESULTS

Median follow-up after PPRT was 39 months. Baseline grade ≥2 genitourinary (GU), gastrointestinal (GI) and sexual toxicities were 20.5%, 2.7% and 43.7%, respectively, reflecting ongoing toxicity after radical prostatectomy. Incidence of new (compared to baseline) acute grade ≥2 GU and GI toxicity was 5.8% and 10.6%, respectively. New late grade ≥2 GU, GI and sexual toxicity occurred in 19.1%, 4.7% and 20.2%, respectively. However, many patients also experienced improvements in toxicities. For this reason, prevalence of grade ≥2 GU, GI and sexual toxicities 4 years after PPRT was similar to or lower than baseline (21.7%, 2.6% and 17.4%, respectively). There were no grade ≥4 toxicities.

CONCLUSIONS

Post-prostatectomy IG-IMRT using Australian contouring guidelines appears to have tolerable acute and late toxicity. The 4-year prevalence of grade ≥2 GU and GI toxicity was virtually unchanged compared to baseline, and sexual toxicity improved over baseline. This should reassure radiation oncologists following these guidelines. Late toxicity rates of surgery and PPRT are higher than following definitive IG-IMRT, and this should be taken into account if patients are considering surgery and likely to require PPRT.

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.

[Vesicourethral anastomotic stricture following radical prostatectomy with or without postoperative radiotherapy]

OBJECTIVE

To know the incidence of vesicourethral anastomotic stricture in patients with prostate cancer treated with radical prostatectomy. Our secondary aim was to verify if postoperative radiotherapy increases the risk of presenting anastomotic stricture.

MATERIALS AND METHODS

We retrospectively checked the clinical records of patients that had undergone radical prostatectomy as their primary treatment between January 2000 and December 2008, with a minimum clinical follow-up of 12 months. Of the total patients, 258 met the foregoing requirements. Of them, 25 (9.6%) received postoperative radiotherapy, 12 (48%) received adjuvant radiotherapy and 13 (52%) received salvage radiotherapy. The mean age of the patients that received radiotherapy was 64 (46-77) years. The mean pre-radiotherapy PSA was 2.3 (0.04-26.1) ng/ ml. The mean time between surgery and radiotherapy was 17.4 (3-72) months. The mean dosage administered was 68 (58-70) Gy. The mean follow-up was 50.5 (15-177) months.

RESULTS

Of 25 prostatectomized patients that received radiotherapy, four (16%) developed vesicourethral anastomotic stricture. The mean time from the completion of the radiotherapy until the appearance of the stricture was 4 months (1-22). On the other hand, 36 (15.4%) of the prostatectomized patients that did not receive postoperative radiotherapy presented the same complication. Comparatively, we did not note significant differences between both groups (p=0.599).

CONCLUSIONS

In our retrospective review, postoperative radiotherapy did not significantly increase the incidence of vesicourethral anastomotic stricture.

[Treatment results of salvage radiotherapy for biochemical recurrence after radical prostatectomy]

PURPOSE

In this retrospective study we reported the results of salvage external beam radiotherapy for patients with biochemical recurrence after radical prostatectomy.

MATERIALS AND METHODS

A total of 28 patients with biochemical recurrence after radical prostatectomy underwent salvage radiotherapy with (n=16) or without (n=12) hormonal therapy. Median radiation dose was 60 Gy. Biochemical recurrence after radiotherapy was defined as a single prostate-specific antigen (PSA) of at least 0.1 ng/ml. Potential risk factors were evaluated for significant associations with biochemical recurrence.

RESULTS

The median follow-up period after salvage radiotherapy was 42 months. The actuarial biochemical recurrence free survival rate at 3 and 5 years was 81% and 74%, respectively. Addition of hormonal therapy to salvage radiotherapy did not alter biochemical recurrence rate (P = 0.56). Univariate analysis revealed that Gleason score of 8 to 10 (P = 0.026) and PSA before salvage therapy greater than 0.24 ng/ml (P = 0.0016) were significant risk factors for biochemical recurrence. On multivariate analysis, PSA before salvage therapy greater than 0.24 ng/ml (P = 0.017) maintained statistical significance. Of 28 patients 3 (11%) experienced late grade 3 toxicity of hematuria.

CONCLUSION

Our data suggest that early use of salvage radiotherapy is beneficial for patients with biochemical recurrence after radical prostatectomy.

The role of indium-111 radioimmunoscintigraphy in post-radical retropubic prostatectomy management of prostate cancer patients

Indium-111 radioimmunoscintigraphy (RIS) has an increasing role in the treatment of prostate cancer and is most commonly performed at this disease site using labeled monoclonal antibody against prostate-specific membrane antigen. There are many limitations of RIS, including low spatial resolution, low diagnostic yield and limited availability. Despite these limitations, the efficacy of RIS has been demonstrated in many clinical studies, including multi-institutional investigations. The highest sensitivity and specificity of RIS appears to be in the post-radical retropubic prostatectomy (post-RRP) setting. RIS has recently been explored for its role in clinical radiotherapy decision-making, and was found to have a significant impact in selecting patients for radiotherapy and for the general radiotherapy treatment volume definition. RIS has also recently been explored for its role in radiotherapy planning and was found to impact clinical target volume design. However, manual editing of the RIS volume is still necessary when projected into the radiotherapy-planning scan, as there is often overlap in the RIS-defined uptake regions with normal structures (rectum, bladder and symphysis bone marrow). The impact of RIS on biochemical control has been explored, with studies in this area yielding conflicting results. It appears that the maximum impact of RIS is possible when areas of labeled antibody uptake regions are co-registered with the radiotherapy-planning computed tomography scan. The larger RIS-guided target volumes do not appear to be prohibitive in increasing radiotherapy-related toxicity. Future directions of the use of RIS for post-RRP prostate cancer are discussed.

Outcome of post-prostatectomy radiotherapy in one institution

We present a retrospective study to evaluate the outcome of postoperative radiotherapy for biochemical or clinical recurrent prostate cancer. Twenty-six patients (median age 60 years) underwent radiotherapy after radical prostatectomy between January 1997 and January 2004. Seven patients received adjuvant radiotherapy and 19 received salvage radiotherapy. The median prostate-specific antigen at diagnosis was 8.6 (0.9-89) and most (23 patients) presented with T(3)N(0) disease. The median follow up was 19.5 months (5-84 months). All patients received a dose of 61.2 Gy at 1.8 Gy per fraction, 20 initially receiving 45 Gy to the lesser pelvis. The median dose to the bladder, rectum and left femoral head were 55.6, 57.5 and 33.8 Gy, respectively. All patients were managed radiotherapeutically by the first author. Twenty-four patients are alive. Two patients have died, one from oesophageal cancer and the second from metastatic prostate cancer. Two other patients also developed metastatic disease. Four asymptomatic patients with a rising prostate-specific antigen are under observation. None of the 26 patients has developed a local recurrence. Seven patients have developed grade 1 late bowel effects and three a grade 2 late effect. Eight patients suffer from grade 1 late genitourinary effects and two from grade 2 effects. One patient developed impotence, whereas 23 patients were rendered impotent postoperatively. There were no grade 3/4 late effects. Postoperative radiotherapy is well tolerated and provides effective local control.

Postprostatectomy target-normal structure overlap volume differences using computed tomography and radioimmunoscintigraphy images for radiotherapy treatment planning

PURPOSE

The purpose of this study was to analyze regions of uptake in normal structures on postprostatectomy radioimmunoscintigraphy (RIS) images by evaluating differences in the overlap volumes of prostate fossa clinical target volume (CTV) and planning target volume (PTV) using correlative computed tomography (CT) images.

MATERIALS AND METHODS

The electronic records of 13 patients who received external beam radiotherapy postprostatectomy and who underwent a vessel-based RIS/CT registration were reviewed. For each patient, the RIS-defined CTV (CTV(RIS)) was compared (in terms of the overlap volume with the surrounding bladder, rectum, pubic symphysis, and penile bulb) with the CT-defined CTV(pre) before this registration and also with CTV(post) (the final target volume used for treatment). Similar analyses were done for PTV(RIS), PTV(pre), and PTV(post) defined in each case to be the corresponding CTV + 1-cm margin.

RESULTS

CTV(RIS) overlapped significantly more with the bladder, rectum, and symphysis, but not with the penile bulb, than did either the CTV(pre) or CTV(post). However, the corresponding PTV analyses revealed no significant differences between any of the overlap volumes of any of the PTVs with the bladder, rectum, and penile bulb, but did reveal a significant difference between the PTV(RIS) and PTV(post) overlap volumes with the symphysis compared with PTV(pre) overlap volumes with the symphysis.

CONCLUSIONS

On RIS images, there appear to be areas of uptake in the bladder, rectum, and pubic symphysis but not the penile bulb; however, the dosimetric consequences of this uptake for radiation treatment planning are minimal on the bladder, rectum, and penile bulb, but require segmentation for dose reduction to the pubic symphysis.

Parameters for Treatment Decisions for Salvage Radiation Therapy

Radical prostatectomy (RP) is the most common primary treatment for prostate cancer. About 40% of those with high-risk pathologic features, such as a positive margin or seminal vesicle involvement, will develop biochemical failure at some point in the future. Radiotherapy (RT), with or without concurrent androgen deprivation, has been used liberally in the management of men with a rising prostate-specific antigen (PSA) after RP, based mostly on relatively small retrospective series. Factors such as the prostatectomy Gleason score, seminal vesicle invasion, absolute pre-RT PSA level, and pre-RT PSA doubling time are emerging as important determinants of outcome after RT. These factors should be used as a guide to the options of local therapy alone (RT), local therapy plus systemic therapy (typically androgen deprivation therapy), and systemic therapy alone.

Postprostatectomy adjuvant versus salvage radiotherapy

BACKGROUND

Radiotherapy (RT) has been used with success after radical retropubic prostatectomy (RRP), both in the adjuvant and salvage settings. The purpose of the current investigation was to systematically compare adjuvant versus salvage RT in a manner that incorporates both treatment efficacy and complications.

METHODS

A literature review was performed of reports of post-RRP salvage and adjuvant RT, and 12 trials comprising 1060 patients met the appropriate inclusion criteria. The biochemical failure-free survival in each study/arm was tabulated, and these values were entered into a model to compute an unadjusted number-needed-to treat (NNT). RT complications were then considered, accounting for differences in toxicity incidences in the salvage versus adjuvant setting, to compute complication-adjusted NNTs. In all the trials, the signs and magnitudes of the NNTs obtained were used to compare adjuvant with salvage RT.

RESULTS

The absolute NNT analysis showed an advantage of adjuvant compared with salvage RT. After adjustment for RT complications, however, the advantage shifted to salvage RT. This transition point from superiority of adjuvant RT to superiority of salvage RT was sensitive to the estimated incidence and severity of RT side effects.

CONCLUSIONS

Adjuvant post-RRP RT was advantageous in comparison to salvage RT if the side effects of RT were estimated to be negligible. However, with moderate incidence/severity of RT side effects, salvage RT was advantageous. The findings herein must be tested in a prospective study in which both health-related quality of life and cancer control are documented in patients receiving adjuvant versus salvage post-RRP RT. Further work is needed to better estimate parameters entered into the model to determine the precise transition point between adjuvant and salvage RT with modern RT techniques.