Salvage radiotherapy after radical prostatectomy: prediction of biochemical outcomes

Combination of Abiraterone Acetate, Prostate Bed Radiotherapy, and Luteinizing Hormone-releasing Hormone Agonists in Biochemically Relapsing Patients After Prostatectomy (CARLHA): A Phase 2 Clinical Trial

BACKGROUND

The relevance of next-generation hormone therapies and circulating tumor cells (CTCs) are not elucidated in biochemical recurrence after prostatectomy.

OBJECTIVE

To evaluate the combination of abiraterone acetate plus prednisone (AAP), prostate bed radiotherapy (PBRT), and goserelin in biochemically relapsing men after prostatectomy, and to investigate the utility of CTCs.

DESIGN, SETTING, AND PARTICIPANTS

In this single-arm multicenter phase 2 trial, 46 biochemically relapsing men were enrolled between December 2012 and January 2019. The median follow-up was 47 mo.

INTERVENTION

All patients received AAP 1000 mg daily (but 750 mg during PBRT), salvage PBRT, and goserelin.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was 3-yr biochemical recurrence-free survival (bRFS) when prostate-specific antigen (PSA) levels were ≥0.2 ng/ml. The secondary outcomes included alternative bRFS (alt-bRFS) when PSA levels were ≥0.5 ng/ml and safety assessment. CTC count was assessed.

RESULTS AND LIMITATIONS

The 3-yr bRFS and alt-bRFS were 81.5% (95% confidence interval or CI [66.4-90.3%]) and 95.6% (95% CI [83.5-98.9%]), respectively. The most common acute radiotherapy-related adverse effect (AE; all grades was pollakiuria (41.3%). The most common late AE (all grades) was urinary incontinence (15.2%). Grade 3-4 acute or late radiotherapy-related AEs were scarce. Most frequent AEs nonrelated to radiotherapy were hot flashes (76%), hypertension (63%), and hepatic cytolysis (50%, of which 20% were of grades 3-4). Of the patients, 11% had a CTC count of ≥5, which was correlated with poorer bRFS (p = 0.042) and alt-bRFS (p = 0.008). The association between CTC count and higher rates of relapse was independent of the baseline PSA level and PSA doubling time (p = 0.42 and p = 0.09, respectively). This study was nonrandomized with a limited number of patients, and few clinical events were reported.

CONCLUSIONS

Adding AAP to salvage radiation therapy and goserelin resulted in high bRFS and alt-bRFS. AEs remained manageable, although a close liver surveillance is advised. CTC count appears as a promising biomarker for prognosis and predicting response to treatment.

PATIENT SUMMARY

Our study was a phase 2 clinical trial that exhibited the efficacy and tolerance of a novel androgen-receptor targeting agent (abiraterone acetate plus prednisone) in patients with prostate cancer who experienced rising prostate-specific antigen after radical prostatectomy, in combination with prostate bed radiotherapy. The results also indicated the feasibility and potential value of circulating tumor cell detection, which constitutes a possible advance in managing prostate cancers.

Predictive factors for disease progression after salvage radiation therapy in biochemical recurrent patients treated by radical prostatectomy

Objective

Salvage radiation therapy (SRT) is standard treatment for patients after radical prostatectomy (RP). However, the optimal timing of SRT remains to be elucidated.

Material and methods

We retrospectively reviewed 133 prostate cancer (PCa) patients who underwent SRT for biochemical recurrence after RP. Disease progression was defined as repeated prostate-specific antigen (PSA) level more than 0.2 ng/mL, greater than the post-SRT nadir or radiographic progression. A receiver operating characteristic curve analysis was used to identify the optimal pre-SRT PSA level for predicting progression after SRT. Cox regression analyses were performed to elucidate the association between clinicopathologic characteristics and disease progression.

Results

Fifty-one PCa patients (38.4%) experienced disease progression after SRT. The optimal cutoff value of the pre-SRT PSA for predicting disease progression was 0.44 ng/mL. In multivariable analysis, pre-SRT PSA >0.44 ng/mL was a significant independent predictor of post-SRT disease progression [hazard ratio (HR): 2.02, P = 0.02]. Although the pre-SRT PSA >0.44 ng/mL did not maintain its independent association with disease progression in the multivariable analysis of patients with adverse pathology (HR: 1.63, P = 0.22), PSA within 4 weeks after RP as a continuous variable was significantly associated with disease progression (HR: 1.19, P = 0.04).

Conclusions

Our results highlight that in PCa patients who undergo RP, SRT should be performed before their PSA reaches 0.44 ng/mL. In patients with adverse pathology disease, a high PSA level within the 4 weeks after RP might identify those who are likely to have disease progression, and these patients might require systemic therapy.

Stereotactic Radiotherapy after Radical Prostatectomy in Patients with Prostate Cancer in the Adjuvant or Salvage Setting: A Systematic Review

Simple Summary

Stereotactic body radiotherapy, a type of high-precision radiotherapy delivering high doses within few treatment sessions has proven to be effective and well tolerated in prostate cancer patients treated with definite radiotherapy. This systematic review summarizes the available data and analyzes whether this modern treatment may routinely be offered to prostate cancer patients after radical prostatectomy.

Abstract

(1) Background: Prostate cancer is the most common cancer in men and can be treated with radical prostatectomy (RPE) or radiotherapy in the primary setting. Stereotactic radiotherapy (SBRT) has proven to be effective and well tolerated in this setting. However, if SBRT is an equally promising treatment option if applied in the adjuvant or salvage setting after RPE remains unknown. (2) Methods: We searched the PubMed and Embase databases with the following full-text queries in August 2021 for any combination of the terms “SBRT”, “prostate”, “adjuvant”, “postoperative”, “salvage”, “stereotactic radiotherapy”, “prostate bed”. There were no limitations regarding publication date or language. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. (3) Results: We identified 11 individual studies that were included in this systematic review. Three publications included patients without prior radiotherapy and the remaining eight patients with prior radiotherapy. In all but two publications the radiation target was the macroscopic recurrence. SBRT was overall well tolerated with acceptable rates of acute and late gastrointestinal or genitourinary toxicity. Quality of life was published for two phase I trials with good results. There was a very heterogeneous reporting on biochemical control after SBRT. (4) Conclusions: At this point, ultra-hypofractionated RT using SBRT to the prostate bed remains experimental and its use should be restricted to clinical trials. Given the biological rationale for extreme hypofractionation in patients with prostate cancer and the acceptable toxicity rates that have been reported, further exploration of this field is warranted.

The effects of PSA kinetics on the outcome of hypofractionated salvage radiotherapy for biochemical recurrence of prostate cancer after prostatectomy

The feasibility and efficacy of hypofractionated salvage radiotherapy (HS-RT) for prostate cancer (PC) with biochemical recurrence (BR) after prostatectomy, and the usefulness of prostate-specific antigen (PSA) kinetics as a predictor of BR, were evaluated in 38 patients who received HS-RT without androgen deprivation therapy between May 2009 and January 2017. Their median age, PSA level and PSA doubling time (PSA-DT) at the start of HS-RT were 68 (53-74) years, 0.28 (0.20-0.79) ng/ml and 7.7 (2.3-38.5) months, respectively. A total dose of 60 Gy in 20 fractions (three times a week) was three-dimensionally delivered to the prostate bed. After a median follow-up of 62 (30-100) months, 19 (50%) patients developed a second BR after HS-RT, but only 1 patient died before the last follow-up. The 5-year overall survival and BR-free survival rates were 97.1 and 47.4%, respectively. Late grade 2 gastrointestinal and genitourinary morbidities were observed in 0 and 5 (13%) patients, respectively. The PSA level as well as pathological T-stage and surgical margin status were regarded as significant predictive factors for a second BR by multivariate analysis. BR developed within 6 months after HS-RT in 11 (85%) of 13 patients with a PSA-DT < 10 months compared with 1 (17%) of 6 with a PSA-DT ≥ 10 months (median time to BR: 3 vs 14 months, P < 0.05). Despite the small number of patients, our HS-RT protocol seems feasible, and PSA kinetics may be useful for predicting the risk of BR and determining the appropriate follow-up schedule.

Disease Control With Delayed Salvage Radiotherapy for Macroscopic Local Recurrence Following Radical Prostatectomy

Purpose: To retrospectively assess clinical outcomes and toxicity profile of prostate cancer patients treated with delayed dose-escalated image-guided salvage radiotherapy (SRT) for macroscopic local recurrence after radical prostatectomy (RP). Material and Methods: We report on a cohort of 69 consecutive patients with local recurrence after RP and no evidence of regional or distant metastasis who were referred for salvage radiotherapy between 2007 and 2016. SRT consisted of 64-66 Gy (2 Gy/fraction) to the prostatic bed followed by dose escalation to 72-74 Gy (2Gy/fraction) to the macroscopic disease. All patients received concurrent short-term androgen deprivation therapy (ADT). Biochemical recurrence-free survival (bRFS) and clinical progression-free-survival (cPFS) were depicted using Kaplan-Meier method. Multivariable Cox proportional hazards regression assessed predictors of survival outcomes. Baseline, acute, and late urinary and gastrointestinal (GI) toxicity rates were reported using CTCAE v4.03. Results: Median time from RP to SRT was 66 months (IQR: 32-124). Median pre-SRT prostate-specific antigen (PSA) was 2.7 ng/ml (IQR: 0.9-6.5). Median follow-up after SRT was 38 months (IQR: 24-66). The 3- and 5-year bRFS were 58 and 44%, respectively. The 3- and 5-year cPFS were 91 and 76%, respectively. Median time from SRT to clinical disease progression was 102 months (IQR 77.5-165). At baseline, 3 patients (4%) had grade 3 urinary symptoms. Six patients (9%) developed acute and six patients (9%) developed late grade 3 urinary toxicity. Five patients (7%) had acute grade 2 GI toxicity. No acute grade 3 GI toxicity was reported. Late grade 3 GI toxicity was reported in one patient (1.5%). Conclusions: Delayed dose-escalated SRT combined with short-course ADT for macroscopic LR after RP was associated with 44% bRFS and 76% cPFS at 5 years. Albeit improved patient stratification is warranted, these data suggest that delayed SRT provides inferior tumor control compared to early intervention.

Optimizing the Timing of Salvage Postprostatectomy Radiotherapy and the Use of Concurrent Hormonal Therapy for Prostate Cancer

CONTEXT

Currently, salvage radiotherapy (SRT) is the only known curative intervention for men with recurrent disease following prostatectomy. Critical issues in the optimal selection and management of men being considered for SRT include the threshold prostate-specific antigen (PSA) value at which to initiate treatment (ie, pre-SRT PSA) and the role of concurrent hormonal therapy (HT).

OBJECTIVE

To review the published evidence pertaining to the optimal timing for SRT and the role of concurrent HT.

EVIDENCE ACQUISITION

MEDLINE (via PubMed), EMBASE, the Cochrane Central Register of Controlled Trials, and guideline statements from professional organizations were queried from January 1, 2000 through January 10, 2018.

EVIDENCE SYNTHESIS

Thirty-three independent reports, including two randomized trials evaluating HT with SRT, were identified. Retrospective data suggest that SRT initiation at lower pre-SRT PSA levels is associated with better clinical outcomes. Prospective data suggest an overall survival benefit with concurrent HT that manifests during long-term follow-up, with the caveat that hypothesis-generating subgroup analyses suggest that this benefit may be limited to patients with higher pre-SRT PSA levels. Patients with adverse risk factors, such as Gleason grade group 4-5 disease, are likely to benefit the most from earlier SRT initiation and/or the use of HT.

CONCLUSIONS

Given the limitations of the available data, it is imperative that physicians participate in shared decision-making, with the recommendation tailored for each man's desire to maximize oncologic benefit (with a risk of overtreatment) versus potential quality-of-life optimization (with a risk of undertreatment). Within that framework, a significant body of retrospective data supports initiation of SRT at low pre-SRT PSA values, without an arbitrary absolute threshold. Prospective data suggest a benefit of HT, but this benefit may be greatest in patients with a pre-SRT PSA that is higher than the typical level in most patients receiving "early" SRT. Further research is necessary before absolute recommendations can be made.

PATIENT SUMMARY

Two ways to potentially improve outcomes following salvage radiotherapy for prostate cancer that recurs after prostatectomy are to start treatment at a lower prostate-specific antigen level and to use concurrent hormonal therapy. Our review suggests that the available evidence is imperfect, but highlights that both measures are likely to improve clinical outcomes in general, but perhaps not uniformly and/or consistently for all patients. Physician-patient shared decision-making and further research are critical.

Functional and oncological outcomes of salvage external beam radiotherapy following robot-assisted radical prostatectomy in a Canadian cohort

INTRODUCTION

We sought to determine the impact of salvage radio-therapy (SRT) on oncological and functional outcomes of patients with prostate cancer after biochemical recurrence (BCR) following robot-assisted radical prostatectomy (RARP).

METHODS

Data of 70 patients with prostate cancer treated with SRT after developing BCR were retrospectively analyzed from a prospectively collected RARP database of 740 men. Oncological (prostate-specific antigen [PSA]) and functional (pads/day, International Prostate Symptom Score [IPSS], and Sexual Health Inventory for Men [SHIM]) outcomes were reported at six, 12, and 24 months after RT and adjusted for pre-SRT status.

RESULTS

Men who underwent SRT had a mean age, PSA, and time from radical prostatectomy (RP) to RT of 61.8 years (60.1-63.6), 0.5 ng/ml (0.2-0.8), and 458 days (307-747), respectively. Freedom from biochemical failure (FFBF) post-SRT, defined as a PSA nadir <0.2 ng/mL, was observed in 89%, 93%, and 81%, at six, 12, and 24 months, respectively. Undetectable PSA was observed in 14%, 35%, and 40% at the same time points, respectively. There was no significant difference in urinary continence post-SRT (p=0.56). Rate of strict continence (0 pads/day) was 71% at 24 months compared to 78% pre-SRT. Mean IPSS at six, 12, and 24 months was 3.4, 3.6, and 3.6, respectively compared to pre-RT score of 3.3 (p=0.61). The mean SHIM score pre-SRT was comparable at all time points following treatment (p=0.86).

CONCLUSIONS

In this unique Canadian experience, it appears that early SRT is highly effective for the treatment of BCR following RARP with little impact on urinary continence and potency outcomes.

The Role of PET/MR Imaging in Precision Medicine

Fluorodeoxyglucose PET and PET/computed tomography have gained acceptance in the evaluation of disease. Nontargeted tracers have been used in the diagnosis of certain malignancies but may not be sensitive or specific enough to become standard of care. Newer targeted PET tracers have been developed that target disease-specific biomarkers, and allow accurate and sensitive detection of disease. Combined with the capabilities of MR imaging to evaluate soft tissue, precision imaging with PET/MR imaging can change the diagnosis. This article discusses specific areas in which precision imaging with nontargeted and targeted diagnostic agents can change the diagnosis and treatment.

A new predictive tool for postoperative radiotherapy in prostate cancer

The standard treatments of localized prostate cancer include surgical resection and/or radiotherapy. Recently in 2016, Zhao et al. described a tool to predict which patients will most likely gain from postoperative radiotherapy. Such a method can personalize treatment plan by maximizing benefit but minimizing harm.

Adjuvant and Salvage Radiotherapy after Radical Prostatectomy in Prostate Cancer Patients

CONTEXT

Prostate cancer (PCa) patients found to have adverse pathologic features following radical prostatectomy (RP) are less likely to be cured with surgery alone.

OBJECTIVE

To analyze the role of postoperative radiotherapy (RT) in patients with aggressive PCa.

EVIDENCE ACQUISITION

We performed a systematic literature review of the Medline and EMBASE databases. The search strategy included the terms radical prostatectomy, adjuvant radiotherapy, and salvage radiotherapy, alone or in combination. We limited our search to studies published between January 2009 and August 2016.

EVIDENCE SYNTHESIS

Three randomized trials demonstrated that immediate RT after RP reduces the risk of recurrence in patients with aggressive PCa. However, immediate postoperative RT is associated with an increased risk of acute and late side effects ranging from 15% to 35% and 2% to 8%, respectively. Retrospective studies support the oncologic efficacy of initial observation followed by salvage RT administered at the first sign of recurrence; however, the impact of this delay on long-term control remains uncertain. Hopefully, ongoing randomized trials will shed light on the role of adjuvant RT versus observation±salvage RT in individuals with adverse features at RP. Accurate patient selection based on clinical characteristics and molecular profile is crucial. Dose escalation, whole-pelvis RT, novel techniques, and the use of hormonal therapy might improve the outcomes of postoperative RT.

CONCLUSIONS

Immediate RT reduces the risk of recurrence after RP in patients with aggressive disease. However, this approach is associated with an increase in the incidence of short- and long-term side effects. Observation followed by salvage RT administered at the first sign of recurrence might be associated with durable cancer control, but prospective randomized comparison with adjuvant RT is still awaited. Dose escalation, refinements in the technique, and the concomitant use of hormonal therapies might improve outcomes of patients undergoing postoperative RT.

PATIENT SUMMARY

Postoperative radiotherapy has an impact on oncologic outcomes in patients with aggressive disease characteristics. Salvage radiotherapy administered at the first sign of recurrence might be associated with durable cancer control in selected patients but might compromise cure in others.

Radiotherapy after prostatectomy: prognosis, timing and outcomes

Biochemical disease-free survival following radical prostatectomy can be improved with the use of adjuvant and salvage radiotherapy. However, there is a lack of consensus over the ideal timing to start adjuvant and salvage radiotherapy after surgery. The literature in relation to adjuvant and salvage radiotherapy following radical prostatectomy was reviewed, focusing specifically on the prognostic factors that influence the need for postoperative radiotherapy, outcomes following adjuvant and salvage radiotherapy and potential side effects. Post-surgery prognostic factors can be useful in identifying patients early on who may benefit from adjuvant radiotherapy. While there is literature examining the role of radiotherapy following radical prostatectomy, few dedicated trials investigate this area thoroughly.

Detection of prostate cancer local recurrence following radical prostatectomy: assessment using a continuously acquired radial golden-angle compressed sensing acquisition

PURPOSE

To compare image quality and diagnostic performance for detecting local recurrence (LR) of prostate cancer after radical prostatectomy (RP) between standard dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and a high spatiotemporal resolution, continuously acquired Golden-angle RAdial Sparse Parallel acquisition employing compressed sensing reconstruction ("GRASP").

METHODS

A search was conducted for prostate MRI examinations performed in patients with PSA ≥0.2 ng/mL after RP in whom follow-up evaluation allowed classification as positive (≥50% PSA reduction after pelvic radiation or positive biopsy) or negative (<50% PSA reduction after pelvic radiation; spontaneous PSA normalization) for LR, yielding 13 patients with standard DCE (11 LR+) and 12 with GRASP (10 LR+). Standard DCE had voxel size 3.0 × 1.9 × 1.9 mm and temporal resolution 5.5 s. GRASP had voxel size 1.0 × 1.1 × 1.1 cm and was retrospectively reconstructed at 2.3 s resolution. Two radiologists evaluated DCE sequences for image quality measures (1-5 scale) and the presence of LR.

RESULTS

GRASP achieved higher scores than standard DCE from both readers (p < 0.001-0.136) for anatomic clarity (R1: 4.4 ± 0.8 vs. 2.8 ± 0.67 R2: 4.8 ± 0.5 vs. 3.2 ± 0.6), sharpness (3.6 ± 0.9 vs. 2.5 ± 0.7; 4.6 ± 0.5 vs. 2.6 ± 0.5), confidence in interpretation (3.8 ± 0.8 vs. 3.1 ± 0.9; 3.8 ± 1.0 vs. 3.1 ± 1.2), and conspicuity of detected lesions (4.7 ± 0.5 vs. 3.8 ± 1.1; 4.5 ± 0.5 vs. 3.8 ± 1.0). For detecting LR, GRASP also achieved higher sensitivity (70% vs. 36%; 80% vs. 45%), specificity (R1 and R2: 100% vs. 50%), and accuracy (75% vs. 38%; 83% vs. 46%) for both readers.

CONCLUSION

Although requiring larger studies, high spatiotemporal resolution GRASP achieved substantially better image quality and diagnostic performance than standard DCE for detecting LR in patients with elevated PSA after prostatectomy.

Proposal for magnetic resonance imaging-guided salvage radiotherapy for prostate cancer

BACKGROUND

A subset of patients experience a biochemical recurrence following radical prostatectomy. Radiotherapy can salvage those patients, provided that all disease is encompassed within the target volume. We hypothesized that this can be achieved more adequately with magnetic resonance imaging (MRI)-guided treatment planning.

MATERIAL AND METHODS

From January 2009 to April 2014, 183 patients were referred to our department for salvage radiotherapy (SRT). According to protocol, patients received a planning computed tomography (CT) as well as an MRI in treatment position. All MRI scans were retrospectively reviewed by an experienced uro-radiologist.

RESULTS

Median prostate-specific antigen (PSA) value at time of referral was 0.3 ng/ml (range 0.02-4.7 ng/ml). MRI did not show any suspected macroscopic disease in 137 patients (75%). In 46 (25%) patients, MRI did indicate a pelvic recurrence. The mean PSA level was significantly higher in patients with a suspected recurrence on MRI (0.4 vs. 1.4 ng/ml, p < .001) on a Student's t-test. The mean follow-up was 33 months (range 5-69 months). Biochemical disease-free survival (bDFS) was significantly worse in patients with suspected disease on MRI [hazard ratio (HR) 2.9, p < .0001]. bDFS was significantly worse in the subgroup where the macroscopic recurrences on MRI received a lower radiation dose (HR 3.4, p = .01).

CONCLUSION

MRI detects loco-regional disease in a substantial subset of patients with a biochemical recurrence after prostatectomy, especially in a PSA above 0.5 μg/l. Lack of MRI-based dose escalation on these macroscopic recurrences could explain some of the biochemical progression observed after SRT.

Optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy: is ultra-early salvage radiotherapy beneficial?

Background

The optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy is controversial. In particular, the prognostic significance of salvage radiotherapy delivered before a current definition of biochemical recurrence, i.e. ultra-early salvage radiotherapy, is unclear.

Methods

We reviewed 76 patients with pT2-3N0M0 prostate cancer who underwent salvage radiotherapy for post-prostatectomy biochemical recurrence at the following three timings: ultra-early salvage radiotherapy (n = 20) delivered before meeting a current definition of biochemical recurrence (two consecutive prostate-specific antigen [PSA] values ≥0.2 ng/mL); early salvage radiotherapy (n = 40) delivered after meeting the definition but before PSA reached 0.5 ng/mL; and delayed salvage radiotherapy (n = 16) delivered after PSA reached 0.5 ng/mL. The primary endpoint was failure of salvage radiotherapy, defined as a PSA value ≥0.2 ng/mL. The log-rank test and Cox proportional hazards model were used for univariate and multivariate analyses, respectively.

Results

During the follow-up period (median: 70 months), four of 20 (20 %), nine of 40 (23 %) and seven of 16 (44 %) patients failed biochemically in the ultra-early, early and delayed salvage radiotherapy groups, respectively. On univariate analyses, the outcome of delayed salvage radiotherapy was worse than the others, while there was no significant difference between ultra-early and early groups. Multivariate analysis demonstrated the presence of Gleason pattern 5, perineural invasion and delayed salvage radiotherapy as independent predictors of poorer survival.

Conclusions

No survival benefit of ultra-early salvage radiotherapy was demonstrated, whereas delayed salvage radiotherapy was associated with worse outcome as reported in previous studies. Our results may support the current recommendations that salvage radiotherapy should be undertaken after two consecutive PSA values ≥0.2 ng/mL and before reaching 0.5 ng/mL.

Risk stratification system and pattern of relapse in patients treated with adjuvant radiotherapy after radical prostatectomy

PURPOSE

To retrospectively evaluate the role of adjuvant radiotherapy (ART) as monotherapy in a cohort of prostate cancer patients with undetectable prostate-specific antigen (PSA) after surgery and to propose a risk stratification system.

METHODS

Between 2003 and 2010, 174 consecutive patients were treated with ART (median dose 71 Gy) at a single institution. Subsequently, we assigned a score of 1 to the following risk factors (RF): T stage ≥3b, presurgical PSA ≥10 ng/mL, pathologic Gleason score (GS) ≥4 + 3, and positive surgical margin (R1). The scores were then summed to stratify the population into low risk (LR), intermediate risk (IR), and high risk (HR).

RESULTS

Median follow-up was 61 months (range 4-105). Five-year biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), and overall survival (OS) were respectively 93%, 97.1%, and 98.6%. On univariate analyses, GS was the only variable related to bRFS (p = 0.04) and to cRFS (p = 0.05). Any variable was related to OS. Kaplan-Meier analysis showed that HR patients (3-4 RF) had a worse bRFS (p = 0.02) compared to LR patients (0 RF or R1 as single RF); IR patients (1-2 RF) had a lower bRFS compared to LR patients (p = 0.06). Patients with R1 as single RF have the same bRFS as patients with 0 RF (p = 0.6) and are considered as LR patients.

CONCLUSIONS

Adjuvant radiotherapy leads to excellent bRFS and cRFS rates at 5 years (93.3% and 97.1%, respectively) in our population. Patients with multiple RF are at higher risk of bRFS. Patients with R1 as single RF have bRFS rates comparable to patients without any RF.

Factors influencing biochemical recurrence in patients who have received salvage radiotherapy after radical prostatectomy: a systematic review and meta-analysis

Several studies have evaluated the risk factors influencing biochemical recurrence (BCR) of prostate cancer in patients receiving salvage radiotherapy (SRT) for BCR after radical prostatectomy (RP), but the results remain conflicting. In this study, we performed a meta-analysis to resolve this conflict. We searched the following databases: PubMed, Embase, and Web of Science using the following terms in "All fields": "salvage radiation therapy," "salvage IMRT," "S-IMRT," "salvage radiotherapy," "SRT," "radical prostatectomy," "RP," "biochemical recurrence," "BCR," "biochemical relapse." Eleven studies, with a total of 1383 patients, were included in our meta-analysis. Of all the variables, only Gleason score (GS) ≥7 (odds ratio [OR]: 3.82; 95% confidence interval [CI]: 2.60-5.64) and pathological tumor (pT) stage ≥3a (OR: 1.82; 95% CI: 1.36-2.42) were positively correlated with BCR. However, SRT combined with androgen deprivation therapy (ADT) (OR: 0.63; 95% CI: 0.44-0.90) and radiation therapy (RT) dose ≥64 Gy (OR: 0.35; 95% CI: 0.19-0.64) were negatively correlated with BCR. Perineural invasion (OR: 2.64; 95% CI: 1.11-6.26), preoperative prostate-specific antigen (PSA) ≥10 ng ml-1 (OR: 1.36; 95% CI: 0.94-1.96), positive surgical margin (OR: 0.92; 95% CI: 0.7-1.19), and seminal vesicle involvement (SVI) (OR: 1.09; 95% CI: 0.83-1.43) had no effect on BCR. Our meta-analysis indicated that pT stage, GS, RT dose, and SRT combined with ADT may influence BCR, while preoperative PSA, surgical margin, perineural invasion, and SVI have only a weak effect on BCR.

Prostate Cancer: Utility of Whole-Lesion Apparent Diffusion Coefficient Metrics for Prediction of Biochemical Recurrence After Radical Prostatectomy

OBJECTIVE

The purpose of this study was to investigate the additional value of whole-lesion histogram apparent diffusion coefficient (ADC) metrics, when combined with standard pathologic features, in prediction of biochemical recurrence (BCR) after radical prostatectomy for prostate cancer.

MATERIALS AND METHODS

The study included 193 patients (mean age, 61 ± 7 years) who underwent 3-T MRI with DWI (b values, 50 and 1000 s/mm(2)) before prostatectomy. Histogram metrics were derived from 3D volumes of interest encompassing the entire lesion on ADC maps. Pathologic features from radical prostatectomy and subsequent BCR were recorded for each patient. The Fisher exact test and Mann-Whitney test were used to compare ADC-based metrics and pathologic features between patients with and patients without BCR. Stepwise logistic regression analysis was used to construct multivariable models for prediction of BCR, which were assessed by ROC analysis.

RESULTS

BCR occurred in 16.6% (32/193) of patients. Variables significantly associated with BCR included primary Gleason grade, Gleason score, extraprostatic extension, seminal vesicle invasion, positive surgical margin, preoperative prostate-specific antigen level, MRI tumor volume, mean whole-lesion ADC, entropy ADC, and mean ADC of the bottom 10th, 10-25th, and 25-50th percentiles (p ≤ 0.019). Significant independent predictors of BCR at multivariable analysis were primary Gleason grade, extraprostatic extension, mean of the bottom 10th percentile ADC, and entropy ADC (p = 0.002-0.037). The AUC of this multivariable model was 0.94 for prediction of BCR; the AUC of pathologic features alone was 0.89 (p = 0.001).

CONCLUSION

A model integrating whole-lesion ADC metrics had significantly higher performance for prediction of BCR than did standard pathologic features alone and may help guide postoperative prognostic assessments and decisions regarding adjuvant therapy.

PSMA PET/CT with Glu-urea-Lys-(Ahx)-[⁶⁸Ga(HBED-CC)] versus 3D CT volumetric lymph node assessment in recurrent prostate cancer

Purpose

PET/CT with the PSMA ligand is a powerful new method for the early detection of nodal metastases in patients with biochemical relapse. The purpose of this retrospective investigation was to evaluate the volume and dimensions of nodes identified by Glu-urea-Lys-(Ahx)-[⁶⁸Ga(HBED-CC)] (⁶⁸Ga-PSMA-11) in the setting of recurrent prostate cancer.

Methods

All PET/CT images were acquired 60 ± 10 min after intravenous injection of ⁶⁸Ga-PSMA-11 (mean dose 176 MBq). In 21 patients with recurrent prostate cancer and rising PSA, 49 PSMA-positive lymph nodes were identified. Using semiautomated lymph node segmentation software, node volume and short-axis and long-axis dimensions were measured and compared with the maximum standardized uptake values (SUVmax). Round nodes greater than or equal to 8 mm were considered positive by morphological criteria alone. The percentage of nodes identified by elevated SUVmax but not by conventional morphological criteria was determined.

Results

The mean volume of ⁶⁸Ga-PSMA-11-positive nodes was 0.5 ml (range 0.2 – 2.3 ml), and the mean short-axis diameter was 5.8 mm (range 2.4 – 13.3 mm). In 7 patients (33.3 %) with 31 PSMA-positive nodes only 11 (36 %) were morphologically positive based on diameters >8 mm on CT. In the remaining 14 patients (66.7 %), 18 (37 %) of PSMA positive lymph nodes had short-axis diameters <8 mm with a mean short-axis diameter of 5.0 mm (range 2.4 – 7.9 mm). Thus, in this population, ⁶⁸Ga-PSMA-11 PET/CT detected nodal recurrence in two-thirds of patients who would have been missed using conventional morphological criteria.

Conclusion

⁶⁸Ga-PSMA-11 PET/CT is more sensitive than CT based 3D volumetric lymph node evaluation in determining the node status of patients with recurrent prostate cancer, and is a promising method of restaging prostate cancers in this setting.