ACR Appropriateness Criteria® Postradical Prostatectomy Irradiation in Prostate Cancer

Management of Postprostatectomy Biochemical Relapse With Salvage Radiotherapy: Results of an International Survey

OBJECTIVES

The management of patients with postprostatectomy salvage radiotherapy (SRT) presents radiation oncologists (ROs) with multiple treatment decisions that may impact outcomes. As the evidence addressing these issues is limited to retrospective data, it was hypothesized that widely disparate treatment paradigms exist.

METHODS

A 21-question survey was sent through SurveyMonkey to members of the American Society of Radiation Oncology.

RESULTS

A total of 999 ROs responded. Threshold rPSA values to initiate SRT ranged from 0.1 to 1 ng/mL. The highest dose prescribed by ROs ranged from <60 to >70.2 Gy. Elective lymph node irradiation was offered by 74%, and the majority (64%) referenced the Roach formula, Kattan nomogram, or D'Amico risk stratification to decide when it was appropriate. There was variability in pelvic field design with a preference to place the superior field border at either the upper, middle, or lower sacroiliac joint by 57.6%, 28.8%, and 13.6% of respondents, respectively. Adjuvant androgen deprivation therapy (ADT) was offered by 74%.

CONCLUSIONS

Disparate treatment paradigms exist for SRT that may impact patient outcomes. Variability includes patient selection, treatment design, and recommendations for ADT. Many reference formulas to predict the benefit of pelvic lymph node irradiation that are not yet validated in the postprostatectomy setting. These data make it clear that well-designed, prospective clinical trials are needed to better evaluate the role of larger treatment fields, dose escalation, and ADT for the thousands of patients who are treated with postprostatectomy SRT each year.

Adjuvant and salvage radiation therapy after prostatectomy: investigating beliefs and practices of radiation oncologists

OBJECTIVE

Evidence regarding adjuvant radiation therapy (ART) and salvage radiation therapy (SRT) following radical prostatectomy (RP) for prostate cancer is inconsistent. The study objectives were to collect survey information on Italian radiation oncologists' (RO) beliefs regarding the use of ART and SRT following RP and to compare the results of Italian RO with those of American RO available from an analogous survey.

METHODS

A modified version of a US-based questionnaire captured attitudes and clinical approaches regarding post-RP RT of all 716 RO practicing in 147 radiation oncology centres in Italy. Bivariate analyses compared the responses of Italian RO with those of American RO retrieved from a previously published study.

RESULTS

Analysable questionnaires were completed by 153 Italian RO (response rate, 21%). Variations in practice were found for RT use, timing, dosage and technique. All Italian RO supported ART use, although factors influencing the decision to initiate ART varied. Most RO (81%) would wait 3-6 months after surgery before beginning RT. Compared with Italian RO, more American RO believed ART improves survival outcomes (70% vs 35%, p < 0.001), would initiate ART based solely on adverse pathological features (79% vs 69%, p < 0.001) and would initiate SRT based on any detectable prostate-specific antigen (37% vs 11%, p < 0.001).

CONCLUSION

Italian RO strongly supported ART, but their approach to patient selection for ART and SRT varied. Striking differences between Italian RO and American RO regarding ART and SRT practices were found.

ADVANCE IN KNOWLEDGE

Differential RT practices and perceptions exist among RO internationally. Clinical studies must inform evidence-based guidelines to harmonize the use of post-RP RT.

Postoperative radiotherapy in prostate cancer: Analysis of prognostic factors in a series of 282 patients

AIM

To assess the outcomes of patients treated with postoperative RT in relation to the possible prognostic factors.

BACKGROUND

Postoperative radiotherapy (RT) has been proved to reduce the risk of biochemical recurrence in high-risk prostate cancer patients. Baseline prostate specific antigen (PSA), pathological Gleason score (GS), positive surgical margins, nodal status and seminal vesicle invasion are independent predictors of biochemical relapse.

MATERIALS AND METHODS

The clinical records of 282 patients who underwent postoperative RT were retrospectively reviewed. The prognostic value of postoperative PSA, preoperative risk class, nodal status, pathological GS, margins status, and administration of hormonal therapy (HT) was analyzed.

RESULTS

Postoperative RT was delivered with a median dose to the prostatic fossa of 66 Gy (range 50-72) in 1.8-2 Gy/fraction. Median follow-up was 23.1 months (range 6-119). Five-year actuarial biochemical disease-free survival (bDFS) and overall survival rates were 76% and 95%, respectively. Higher bDFS was found for patients with postoperative PSA <0.02 ng/ml (p = 0.03), low preoperative risk class (p = 0.01), pN0 (p = 0.003), GS 4-6 (p = 0.0006), no androgen deprivation therapy (p = 0.02), and irrespective of surgical margin status (p = 0.10). Multivariate analysis showed that postoperative PSA and Gleason score had a significant impact on bDFS (p = 0.039 and p = 0.05, respectively).

CONCLUSIONS

Postoperative RT with a dose of 66 Gy offers an acceptable toxicity and an optimal disease control after radical prostatectomy in patients with different risk features. A postoperative PSA >0.02 ng/ml could be considered as a prognostic factor and a tool to select patients at risk for progression.

Elective irradiation of pelvic lymph nodes during postprostatectomy salvage radiotherapy

BACKGROUND

Success rates with salvage radiotherapy (SRT) in men who have a postprostatectomy biochemical relapse are suboptimal. One treatment-intensification strategy includes elective irradiation of the pelvic lymph nodes with whole pelvis radiotherapy (WPRT).

METHODS

An inter-institutional retrospective cohort study compared outcomes for patients who received SRT at 2 separate academic institutions with disparate treatment paradigms: almost exclusively favoring WPRT (n = 112) versus limiting treatment to the prostate bed (PBRT) (n = 135). Patients were excluded if they had lymph node involvement or if they received androgen-deprivation therapy. The Cox proportional hazards model was used to adjust for potential confounders.

RESULTS

In total, 247 patients were analyzed with a median follow-up of 4 years. The pre-SRT prostate-specific antigen (PSA) level (adjusted hazard ratio [HR], 1.58; P < .0001) and a Gleason score of 8 to 10 (adjusted HR, 3.21; P < .0001) were identified as independent predictors of increased risk of biochemical PSA progression after SRT. However, WPRT was not independently associated with biochemical progression-free survival in the multivariate model (adjusted HR, 0.79; P = .20). Neither low-risk patients nor high-risk patients (defined a priori by a preoperative PSA level ≥20 ng/mL, a pathologic Gleason score between 8 and 10, or pathologic T3 tumor classification) benefited from WPRT. Overall survival was similar between treatment groups. When restricting the analysis to patients with pre-SRT PSA levels ≥0.4 ng/mL (n = 139), WPRT was independently associated with a 53% reduction in the risk of biochemical progression (adjusted HR, 0.47; P = .031).

CONCLUSIONS

WPRT did not improve outcomes among the entire group but was independently associated with improved biochemical control among patients with pre-SRT PSA levels ≥0.4 ng/mL.

Conformal postoperative radiotherapy in patients with positive resection margins and/or pT3-4 prostate adenocarcinoma

PURPOSE

To evaluate outcome and toxicity of high-dose conformal radiotherapy (RT) after radical prostatectomy.

METHODS AND MATERIALS

Between August 1998 and December 2007, 182 consecutive patients with positive resection margins and/or pT3-4, node-negative prostate adenocarcinoma underwent postoperative conformal RT. The prescribed median dose to the prostate/seminal vesicle bed was 66.6 Gy (range 50-70). Hormone therapy (a luteinizing hormone-releasing hormone analogue and/or antiandrogen) was administered to 110/182 (60.5%) patients with high-risk features. Biochemical relapse was defined as an increase of more than 0.2 ng/mL over the lowest postoperative prostate-specific antigen (PSA) value measured on 3 occasions, each at least 2 weeks apart.

RESULTS

Median follow-up was 55.6 months (range 7.6-141.9 months). The 3- and 5-year probability of biochemical relapse-free survival were 87% and 81%, respectively. In univariate analysis, more advanced T stages, preoperative PSA values ≥10 ng/mL, and RT doses <70 Gy were significant factors for biochemical relapse. Pre-RT PSA values >0.2 ng/mL were significant for distant metastases. In multivariate analysis, risk factors for biochemical relapse were higher preoperative and pre-RT PSA values, hormone therapy for under 402 days and RT doses of <70 Gy. Higher pre-RT PSA values were the only independent predictor of distant metastases. Acute genitourinary (GU) and gastrointestinal (GI) toxicities occurred in 72 (39.6%) and 91 (50%) patients, respectively. There were 2 cases of Grade III GI toxicity but no cases of Grade IV. Late GU and GI toxicities occurred in 28 (15.4%) and 14 (7.7%) patients, respectively: 11 cases of Grade III toxicity: 1 GI (anal stenosis) and 10 GU, all urethral strictures requiring endoscopic urethrotomy.

CONCLUSIONS

Postoperative high-dose conformal RT in patients with high-risk features was associated with a low risk of biochemical relapse as well as minimal morbidity.

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.