Postoperative radiotherapy after radical prostatectomy: indications and open questions

Prognostic factors after salvage radiotherapy alone in patients with biochemical recurrence after radical prostatectomy

OBJECTIVES

To evaluate the oncological outcome and to assess prognostic factors of salvage radiotherapy alone in patients with biochemical recurrence after radical prostatectomy.

METHODS

We reviewed our single institution, prospectively maintained database of 2043 patients who underwent radical prostatectomy between September 1995 and December 2011. In this cohort, 149 patients who developed biochemical recurrence after radical prostatectomy and received salvage radiotherapy alone after pelvic magnetic resonance imaging were included. Three-dimensional conformal radiotherapy or intensity-modulated radiotherapy was delivered with a median dose of 70.0 Gy (66.0-78.0 Gy) or 67.2 Gy (64.8-70.0 Gy). Kaplan-Meier and Cox regression analyses were carried out.

RESULTS

With a median follow up of 82 months (range 20-153 months), 55 patients (36.9%) failed salvage radiotherapy. The 5-year salvage radiotherapy failure-free probability was 53.6%. On multivariate analysis, pre-salvage radiotherapy prostate-specific- antigen ≥ 1.0 ng/mL (P = 0.003, hazard ratio 3.592, 95% confidence interval 1.522-8.579), pathological stage ≥ T3a (P = 0.004, hazard ratio 2.261, 95% confidence interval 1.290-3.833), pathological Gleason score ≥ 7 (P = 0.018, hazard ratio 5.501, 95% confidence interval 1.577-21.221), prostate-specific antigen doubling time < 12 months (P = 0.014, hazard ratio 2.243, 95% confidence interval 1.177-4.275) and no visible lesion on pelvic magnetic resonance imaging (P = 0.016, hazard ratio 2.068, 95% confidence interval 1.268-3.501) were independent prognostic factors of salvage radiotherapy failure after radical prostatectomy.

CONCLUSIONS

Pre-salvage radiotherapy prostate-specific antigen ≥ 1.0 ng/mL, pathological stage ≥ T3a, pathological Gleason score ≥ 7, prostate-specific antigen doubling time < 12 months and no visible lesion on pelvic magnetic resonance imaging are prognostic factors of salvage radiotherapy failure after radical prostatectomy. We should consider additional treatment in patients with these factors for favorable outcomes.

Application of a hydrogel spacer for postoperative salvage radiotherapy of prostate cancer

BACKGROUND

In contrast to primary radiotherapy, no reports are available for a hydrogel spacer application in postoperative salvage radiotherapy for prostate cancer.

CASE REPORT

A 77-year-old patient presented 20 years after radical prostatectomy with a digitally palpable local recurrence at the urethrovesical anastomosis (PSA 5.5 ng/ml). The hydrogel spacer (10 ml, SpaceOAR™) was injected between the local recurrence and rectal wall under transrectal ultrasound guidance. Treatment planning was performed with an intensity-modulated technique up to a total dose of 76 Gy in 2-Gy fractions. The same planning was performed based on computed tomography before spacer injection for comparison.

RESULTS

The local recurrence, initially directly on the rectal wall, could be displaced more than  1 cm from the rectal wall after hydrogel injection. With a mean total dose of 76 Gy to the planning target volume, rectal wall volumes included in the 70 Gy, 60 Gy, 50 Gy isodoses were 0 cm(3), 0 cm(3), and 0.4 cm(3) with a spacer and 2.9 cm(3), 4.5 cm(3), and 6.2 cm(3) without a spacer, respectively. The patient reported rectal urgency during radiotherapy, completely resolving after the end of treatment. The PSA level was 5.4 ng/ml a week before the end of radiotherapy and dropped to 0.9 ng/ml 5 months after radiotherapy.

CONCLUSION

A hydrogel spacer was successfully applied for dose-escalated radiotherapy in a patient with macroscopic local prostate cancer recurrence at the urethrovesical anastomosis to decrease the dose at the rectal wall. This option can be considered in specifically selected patients.

[Outcome after radical prostatectomy with extended pelvic lymphadenectomy for untreated high-risk clinically localized prostate cancer]

PURPOSE

We assessed the outcome after radical prostatectomy and extended pelvic lymphadenectomy in patients with untreated high-risk clinically localized prostate cancer, retrospectively.

MATERIALS AND METHODS

Between 2001 and 2010, 89 patients for untreated high-risk clinically localized prostate cancer on the risk classification as defined by D'Amico, underwent retropubic radical prostatectomy and extended pelvic lymphadenectomy. Boundaries of the pelvic lymph node dissection field divided into external iliac vessels, obturator fossa, and internal iliac vessels. We investigated mainly the postoperative outcome of 84 patients without any adjuvant therapies. PSA recurrence-free survival among the pretreatment variables was estimated using Kaplan-Meier plots, and the statistical significance was determined by log rank test.

RESULTS

In 89 high-risk patients, 32.7% had pT3-pT4 tumors, 16.9% positive surgical margin, 6.7% positive lymph node metastases and 30.3% Gleason score 8-10 at the pathological examination. A median of 13 nodes (mean 14.0, range 9-25 nodes) were removed per patient. In 96.6% cases, postoperative PSA values decreased less than 0.2 ng/ml. The median observation period after operation was 1,819 days. Median PSA recurrence-free survival rates, overall survival and cancer cause-specific survival rates at 5 year, in 84 high-risk patients without any adjuvant therapies, were 73.8%, 100% and 100%, respectively. Median PSA recurrence-free survival rates according to pathological T stage and surgical margin status were statistically significant, but that according to preoperative 3 factors (clinical T stage, Gleason score at biopsy, preoperative PSA values) were statistically insignificant. Moreover, that according to both the number of positive preoperative 3 factors (1 vs. 2 positive factors) and the number of removed lymph nodes (< or =13 vs. > or = 14), were statistically insignificant. The median PSA recurrence-free survival rates at 5 year for positive margin cases were 0%.

CONCLUSION

Radical prostatectomy and extended pelvic lymphadenectomy is feasible in patients with high-risk clinically localized prostate cancer. We suggest that both wide resection and extended pelvic lymphadenectomy may improve the postoperative outcome for high-risk clinically localized prostate cancer.