Radiotherapy after prostatectomy: improved biochemical relapse-free survival with whole pelvic compared with prostate bed only for high-risk patients

Salvage Radiotherapy for Relapsed Prostate Cancer after Radical Prostatectomy Is Associated with Normal Life Expectancy

In patients with prostate cancer (PCa), salvage radiotherapy (SRT) for biochemical progression (BP) after radical prostatectomy (RP) improves PCa-specific survival. However, no prospective randomized trials have compared the effect of SRT with untreated patients. In this analysis of 151 patients who received SRT for post-RP BP, we compared their overall survival (OS) with virtual, age-matched controls (n = 151,000) retrieved from government life tables. We also investigated the risk factors associated with BP and OS and compared the prostate-specific antigen (PSA) doubling times (DTs) before and after SRT for patients with BP. The median follow-up was 9.3 years for BP and 17.4 years for OS. The risk factors significantly affecting BP were Gleason score (p < 0.001), pre-SRT PSA (p = 0.003), and negative surgical margins (p = 0.003). None of these risk factors were associated with OS. In 93 patients with BP after SRT, the median PSADT was significantly prolonged compared with pre-SRT values (3.7 vs. 8.3 months, p < 0.001). The OS did not differ between patients and controls (p = 0.112), and life expectancy was similar, likely due to the survival benefit of SRT. The prolonged PSADT after SRT further supports the beneficial role of SRT in this patient population. However, subsequent treatments were not systematically recorded, which may have affected the results.

Radiotherapy after radical prostatectomy for prostate cancer: clinical outcomes and factors influencing biochemical recurrence

BACKGROUND

Radiotherapy (RT) after radical prostatectomy (RP) includes adjuvant radiotherapy (ART) and salvage radiotherapy (SRT), which can prevent or cure biochemical recurrence.

AIMS

To evaluate long-term outcomes of RT after RP and to examine factors affecting biochemical recurrence-free survival (bRFS).

METHODS

Sixty-six received ART and 73 received SRT between 2005 and 2012 were included. The clinical outcomes and late toxicities were evaluated. Univariate and multivariate analyses were performed to examine factors affecting bRFS.

RESULTS

Median follow-up from RP was 111 months. Five-year bRFS and 10-year distant metastasis-free survival from RP were 82.8% and 84.5% in ART, and 74.6% and 92.4% in SRT, respectively. The most frequent late toxicity was hematuria, which was higher in ART (p = .01). No recurrence within RT field was occurred. On univariate analysis, pelvic RT was associated with favorable bRFS in ART (p = .048). In SRT, post-RP prostate-specific antigen (PSA) level (< 0.05 ng/mL), PSA nadir after RT (≤ 0.01 ng/mL), and time to PSA nadir (≥ 10 months) were associated with favorable bRFS (p = .03, p < .001, and p = .002, respectively). On multivariate analysis, post-RP PSA level and time to PSA nadir were independent predictive factors for bRFS in SRT (p = .04 and p = .005).

CONCLUSIONS

ART and SRT had favorable outcomes with no recurrence within RT field. In SRT, the time to PSA nadir after RT (≥ 10 months) was found to be a new predictor for favorable bRFS and useful in assessing treatment efficacy.

Managing postoperative biochemical relapse in prostate cancer, from the perspective of the Francophone group of Urological radiotherapy (GFRU)

Up to 50% of patients treated with radical surgery for localized prostate cancer may experience biochemical recurrence that requires appropriate management. Definitions of biochemical relapse may vary, but, in all cases, consist of an increase in a PSA without clinical or radiological signs of disease. Molecular imaging through to positron emission tomography has taken a preponderant place in relapse diagnosis, progressively replacing bone scan and CT-scan. Prostate bed radiotherapy is currently a key treatment, the action of which should be potentiated by androgen deprivation therapy. Nowadays perspectives consist in determining the best combination therapies, particularly thanks to next-generation hormone therapies, but not exclusively. Several trials are ongoing and should address these issues. We present here a literature review aiming to discuss the current management of biochemical relapse in prostate cancer after radical surgery, in lights of recent findings, as well as future perspectives.

Treatment-related toxicity using prostate bed versus prostate bed and pelvic lymph node radiation therapy following radical prostatectomy: A national population-based study

Purpose There is debate about the effectiveness and toxicity of pelvic lymph node (PLN) irradiation in addition to prostate bed radiotherapy when used to treat disease recurrence following radical prostatectomy. We compared toxicity from radiation therapy (RT) to the prostate bed and pelvic lymph nodes (PBPLN-RT) with prostatebed only radiation therapy (PBO-RT) following radical prostatectomy. Methods and Materials Patients with prostate cancer who underwent post-prostatectomy RT between 2010 and 2016 were identified by using the National Prostate Cancer Audit (NPCA) database. Follow-up data was available up to December 31, 2018. Validated outcome measures, based on a framework of procedural and diagnostic codes, were used to capture ≥Grade 2 gastrointestinal (GI) and genitourinary (GU) toxicity. An adjusted competing-risks regression analysis estimated subdistribution hazard ratios (sHR). A sHR > 1 indicated a higher incidence of toxicity with PBPLN-RT than with PBO-RT. Results 5-year cumulative incidences in the PBO-RT (n = 5,087) and PBPLNRT (n = 593) groups was 18.2% and 15.9% for GI toxicity, respectively. For GU toxicity it was 19.1% and 20.7%, respectively. There was no evidence of difference in GI or GU toxicity after adjustment between PBO-RT and PBPLN-RT (GI: adjusted sHR, 0.90, 95% CI, 0.67-1.19; P = 0.45); (GU: adjusted sHR, 1.19, 95% CI, 0.99-1.44; P = 0.09). Conclusions This national population-based study found that including PLNs in the radiation field following radical prostatectomy is not associated with a significant increase in rates of ≥Grade 2 GI or GU toxicity at 5 years.

Dosimetric impact of rotational set-up errors in high-risk prostate cancer

Introduction: Cone-beam computed tomography (CBCT) provides an excellent solution to quantitative assessment and correction of patient set-up errors during radiotherapy. However, most linear accelerators are equipped with conventional therapy tables that can be moved in three translational directions and perform only yaw rotation. Uncorrected roll and pitch result in rotational set-up errors, particularly when the distance from the isocenter to the target border is large. The aim of this study was to investigate the impact of rotational errors on the dose delivered to the clinical target volume (CTV), the planning target volume (PTV) and organs at risk (OAR).

Material and methods: 30 patients with prostate cancer treated with VMAT technique had daily CBCT scans (840 CBCTs in total) prior to treatment delivery. The rotational errors remaining after on-line correction were retrospectively analysed. The sum plans simulating the dose distribution during the treatment course were calculated for selected patients with significant rotational errors.

Results: The dose delivered to the prostate bed CTV reported in the sum plan was not lower than in the original plan for all selected patients. For four patients from the selected group, the D98% for prostate bed PTV was less than 95%. The V47.88Gy for pelvic lymph nodes PTV was less than 98% for two of the selected patients.

Conclusions: The analysis of the dosimetric parameters showed that the impact of uncorrected rotations is not clinically significant in terms of the dose delivered to OAR and the dose coverage of CTV. However, the PTV dose coverage is correlated with distance away from the isocenter and is smaller than planned.

VMAT partial arc technique decreases dose to organs at risk in whole pelvic radiotherapy for prostate cancer when compared to full arc VMAT and IMRT

Whole pelvic radiotherapy (WPRT) can sterilize microscopic lymph node metastases in treatment of prostate cancer. WPRT, compared to prostate only radiotherapy (PORT), is associated with increased acute gastrointestinal, and hematological toxicities. To further explore minimizing normal tissue toxicities associated with WPRT in definitive IMRT for prostate cancer, this planning study compared dosimetric differences between static 9-field-IMRT, full arc VMAT, and mixed partial-full arc VMAT techniques. In this retrospective study, 12 prostate cancer patients who met the criteria for WPRT were randomly selected for this study. The initial volume, PTV46, included the prostate, seminal vesicles, and pelvic nodes with margin and was prescribed to 4600 cGy. The cone-down volume, PTV78, included the prostate and proximal seminal vesicles with margin to a total dose of 7800 cGy. For each CT image set, 3 plans were generated for each of the PTVs: an IMRT plan, a full arc (FA) VMAT plan, and a mixed partial-full arc (PFA) VMAT plan, using 6MV photons energy. According to RTOG protocols none of the plans had a major Conformity Index (CI) violation by any of the 3 planning techniques. PFA plan had the best mean CI index of 1.00 and significantly better than IMRT (p = 0.03) and FA (p = 0.007). For equivalent PTV coverage, the average composite gradient index of the PFA plans was better than the IMRT and the FA plans with values 1.92, 2.03, and 2.01 respectively. The defference was statistically significant between PFA/IMRT and PFA/FA, with p- values of < 0.001. The IMRT plans and the PFA plans provided very similar doses to the rectum, bladder, sigmoid colon, and femoral heads, which were lower than the dose in the FA plans. There was a significant decrease in the mean dose to the rectum from 4524 cGy with the FA to 4182 cGy with the PFA and 4091 cGy with IMRT (p < 0.001). The percent of rectum receiving 4000 cGy was also the highest with FA at 66.1% compared to 49.9% (PFA) and 47.5% (IMRT). There was a significant decrease in the mean dose to the bladder from 3922 cGy (FA) to 3551 cGy (PFA) and 3612 cGy (IMRT) (p < 0.001). The percent of bladder receiving 4000 cGy was also the highest with FA at 45.4% compared to 36.6% (PFA) and 37.4% (IMRT). The average mean dose to the sigmoid colon decreased from 4177 cGy (FA) to 3893 cGy (PFA) and 3819 cGy (IMRT). The average mean dose to the femoral heads decreased from 2091 cGy (FA) to 2026 cGy (PFA) and 1987 cGy (IMRT). Considering the improvement in plan quality indices recorded in this study including the dose gradient and the dose to organs at risk, mixed partial-full arc plans may be the preferred VMAT treatment technique over full arc plans for prostate cancer treatments that include nodal volumes.

The cost of elective nodal coverage in prostate cancer: Late quality of life outcomes and dosimetric analysis with 0, 45 or 54 Gy to the pelvis

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Pelvic nodal radiation to 54 Gy correlates with worse urinary quality of life.

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Pelvic nodal radiation to 45 Gy does not correlate with urinary quality of life.

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Post-operative radiation resulted in greater urinary quality of life decline.

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Pelvic nodal radiation did not correlate with bowel quality of life.

Purpose

Elective pelvic lymph node radiotherapy (PLNRT) in prostate cancer is often omitted from definitive (n = 267) and post prostatectomy (n = 160) radiotherapy (RT) due to concerns regarding toxicity and efficacy. Data comparing patient-reported outcome measures (PROMs) with or without PLNRT is limited. Our long-term supposition is that PLNRT, particularly to higher doses afforded by IMRT, will decrease pelvic failure rate in select patients. We aim to establish the impact of two different PLNRT doses on long term quality of life (QOL).

Methods and materials

Prostate cancer patients (n = 428) recorded baseline scores using the Expanded Prostate Cancer Index Composite (EPIC), prior to definitive or post-prostatectomy RT. PLNRT, if given, was prescribed to 45 or 54 Gy at 1.8 Gy per fraction. New EPIC scores were recorded 20–36 months after radiotherapy. Absolute change in each domain subscale and summary score was recorded, along with if these changes met minimally important difference (MID) criteria. A separate multivariate analysis (MVA) was performed for each measure. Subsequent dosimetric analysis was performed.

Results

Frequency of a MID decline was significantly greater with PLNRT to 54 Gy for urinary function, incontinence, and overall. No urinary decline was correlated with PLNRT to 45 Gy. PLNRT to 54 Gy was significant for decline in urinary function, bother, irritative, incontinence, and overall score in one or both MVA models while 45 Gy was not. Postoperative status was significant for decline in urinary function, incontinence, and overall. Amongst postoperative patients, there was significantly greater decline in urinary function score in the salvage setting. Neither 54 nor 45 Gy significantly affected bowel subscale or overall score decline.

Conclusions

Using conventional fractionation, adding PLNRT to 54 Gy, but not 45 Gy, correlates with worse urinary QOL, with postoperative patients experiencing a steeper decline. PLNRT had no significant impact on bowel QOL with either dose.

MRI/Transrectal Ultrasound Fusion-Guided Targeted Biopsy and Transrectal Ultrasound-Guided Systematic Biopsy for Diagnosis of Prostate Cancer: A Systematic Review and Meta-analysis

Purpose

For men suspected of having prostate cancer (PCa), the transrectal ultrasound (TRUS)-guided systematic biopsy (SB) was performed. MRI/TRUS fusion guided-targeted biopsy (MRI-TB) could enhance PCa detection, allowing sampling of sites at higher risk which were not obvious with TRUS alone. The aim of this systematic review and meta-analysis was to compare the detection rates of prostate cancer by MRI-TB or MRI-TB plus SB versus SB, mainly for diagnosis of high-risk PCa.

Methods

A literature Search was performed on PubMed, Cochrane Library, and Embase databases. We searched from inception of the databases up to January 2021.

Results

A total of 5831 patients from 26 studies were included in the present meta-analysis. Compared to traditional TRUS-guided biopsy, MRI-TB had a significantly higher detection rate of clinically significant PCa (RR=1.27; 95%CI 1.15-1.40; p<0.001) and high-risk PCa (RR=1.41; 95% CI 1.22-1.64; p<0.001), while the detection rate of clinically insignificant PCa was lower (RR=0.65; 95%CI 0.55-0.77; p<0.001). MRI-TB and SB did not significantly differ in the detection of overall prostate cancer (RR=1.04; 95%CI 0.95-1.12; p=0.41). Compared with SB alone, we found that MRI-TB plus SB diagnosed more cases of overall, clinically significant and high-risk PCa (p<0.001).

Conclusion

Compared with systematic protocols, MRI-TB detects more clinically significant and high-risk PCa cases, and fewer clinically insignificant PCa cases. MRI-TB combined with SB enhances PCa detection in contrast with either alone but did not reduce the diagnosis rate of clinically insignificant PCa.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/#searchadvanced, CRD42021218475.

OLIGOPELVIS GETUG P07, a Multicenter Phase II Trial of Combined High-dose Salvage Radiotherapy and Hormone Therapy in Oligorecurrent Pelvic Node Relapses in Prostate Cancer

BACKGROUND

Oligorecurrent pelvic nodal relapse in prostatic cancer is a challenge for regional salvage treatments. Androgen depriving therapies (ADTs) are a mainstay in metastatic prostate cancer, and salvage pelvic radiotherapy may offer long ADT-free intervals for patients harboring regional nodal relapses.

OBJECTIVE

To assess the efficacy of the combination of ADT and salvage radiotherapy in men with oligorecurrent pelvic node relapses of prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

We performed an open-label, phase II trial of combined high-dose intensity-modulated radiotherapy and ADT (6 mo) in oligorecurrent (five or fewer) pelvic node relapses in prostate cancer, detected by fluorocholine positron-emission tomography computed tomography imaging.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was 2-yr progression-free survival defined as two consecutive prostate-specific antigen levels above the level at inclusion and/or clinical evidence of progression as per RECIST 1.1 and/or death from any cause.

RESULTS AND LIMITATIONS

Between August 2014 and July 2016, 67 patients were recruited in 15 centers. Half of the patients had received prior prostatic irradiation. The median age was 67.7 yr. After a median follow-up of 49.4 mo, 2- and 3-yr progression-free survival rates were 81% and 58%, respectively. Median progression-free survival was 45.3 mo. The median biochemical relapse-free survival (BRFS) was 25.9 mo. At 2 and 3 yr, the BRFS rates were 58% and 46%, respectively. Grade 2 + 2-yr genitourinary and gastrointestinal toxicities were 10% and 2%, respectively.

CONCLUSIONS

Combined high-dose salvage pelvic radiotherapy and ADT appeared to prolong tumor control in oligorecurrent pelvic node relapses in prostate cancer with limited toxicity. After 3 yr, nearly half of patients were in complete remission. Our study showed initial evidence of benefit, but a randomized trial is required to confirm this result.

PATIENT SUMMARY

In this report, we looked at the outcomes of combined high-dose salvage pelvic radiotherapy and 6-mo-long hormone therapy in oligorecurrent pelvic nodal relapse in prostatic cancer. We found that 46% of patients presenting with oligorecurrent pelvic node relapses in prostate cancer were in complete remission after 3 yr following combined treatment at the cost of limited toxicity.

Acute patient-reported intestinal toxicity in whole pelvis IMRT for prostate cancer: Bowel dose-volume effect quantification in a multicentric cohort study

BACKGROUND AND PURPOSE

To assess bowel dose-volume relationships for acute patient-reported intestinal symptoms of patients treated with whole-pelvis intensity-modulated radiotherapy (WPRT) for prostate cancer.

MATERIALS AND METHODS

Complete data of 415 patients enrolled in a multi institute, prospective trial (#NCT02803086) treated with radical (31%), adjuvant (33%) and salvage (36%) intent at a median dose to pelvic nodes/lymph-nodal area of 53 Gy were available. The most severe changes between baseline and radiotherapy mid-point/end toxicity assessed by Inflammatory Bowel Disease Questionnaire (only Bowel Domain) were considered (ΔIBDQ). The 25th percentile values of these score variations were set as endpoints. DVHs of bowel loops for patients with/without toxicity were compared for each endpoint, having excluded patients with baseline scores <5 (rate ranging between 2% and 7% according to the endpoint): the resulting best dosimetric predictors were combined with selected clinical parameters through multivariate logistic regression (MVA) to derive predictive models.

RESULTS

ΔIBDQ ranged between 0.2-1.5 points considering separately each IBDQ symptom. Only four symptoms (IBDQ1 = frequency, IBDQ5 = diarrhea, IBDQ17 = gas passage, IBDQ24 = urgency) showed a median worsening ≥ 1; DVH predicted the risk of worse symptoms for IBDQ5, IBDQ24 and overall Bowel Domain. At multivariable analysis DVHs (best cut-off: V46Gy ≥80 cc) and baseline scores (Odd-Ratio:0.35-0.65) were independently associated to the three end-points. The resulting models were reliable (H&L test: 0.453-0.956), well calibrated (calibration plot: slope = 0.922-1.069, R² = 0.725-0.875) and moderately discriminative (Area Under the Curve:0.628-0.669). A bootstrap-based validation confirmed their robustness.

CONCLUSION

Constraining the bowel loops (V46 < 80 cc) may reduce the risk of several moderate intestinal symptoms, with a much greater impact for patients with lower IBDQ baseline scores.

Toxicity and Biochemical Outcomes of Dose-Intensified Postoperative Radiation Therapy for Prostate Cancer: Results of a Randomized Phase III Trial

PURPOSE

Our purpose was to compare toxicity and biochemical control in postprostatectomy patients treated with conventional (66 Gy) or dose-intensified (72 Gy) radiation therapy.

METHODS AND MATERIALS

Patients who had stage pT3-4, positive surgical margins, or rising prostate-specific antigen ≥ 0.2 ng/mL after radical prostatectomy were randomly assigned to receive either 66 Gy in 33 fractions or 72 Gy in 36 fractions. A primary endpoint was to assess the difference in biochemical progression-free survival (bPFS) between these 2 cohorts, and secondary endpoints were to assess differences in genitourinary (GU), gastrointestinal (GI), and hematologic toxicities between these 2 cohorts. bPFS was estimated by the Kaplan-Meier method and toxicities were compared using the χ² test.

RESULTS

Between September 2011 and November 2016, 144 patients were enrolled: 71 patients to the 66 Gy cohort and 73 patients to the 72 Gy cohort. The median follow-up time was 48.5 months (range, 14-79 months). There was no difference in 4-year bPFS between the 66 Gy and 72 Gy cohorts (75.9% vs 82.6%; P = .299). However, in patients with a higher Gleason score (8-10), the 72 Gy cohort had statistically significant improvement in bPFS compared with the 66 Gy cohort (79.7% vs 55.7%; P = .049). Toxicity analysis showed no difference in ≥2 acute or late GI or GU toxicities between these 2 cohorts. A total of 48 patients were scored as urinary incontinence before radiation therapy, of which 39 (81.3%) reported incontinence recovery or stable at 1-year follow-up, and only 9 (18.8%) patients reported worsening. There was no difference between the 2 cohorts in urinary incontinence either at baseline or at 1-year follow-up.

CONCLUSIONS

Dose escalation (72 Gy) demonstrated no improvement in 4-year bPFS compared with the 66 Gy regimen. However, the dose escalation was not associated with greater acute or late GU or GI toxicities and did not increase urinary incontinence.

Location of Recurrence by Gallium-68 PSMA-11 PET Scan in Prostate Cancer Patients Eligible for Salvage Radiotherapy

OBJECTIVE

To identify locations of recurrence after radical prostatectomy (RP) with prostate-specific antigen (PSA) <2 by Gallium-68 prostate-specific membrane antigen (PSMA)-11 Positron Emission Tomography (PET) imaging, and to determine whether standard nodal radiation fields would cover the location of prostate cancer recurrence.

MATERIALS AND METHODS

We performed a retrospective review of patients with PSMA-PET imaging for biochemical recurrence following RP with PSA ≤2.0 ng/mL and assessed if the recurrent disease was within standard radiation target volumes. We compared patient and clinical variables between men with recurrences covered by standard salvage radiation fields and those with recurrences outside of standard fields.

RESULTS

We identified 125 patients for study inclusion. The median PSA at imaging was 0.40 ng/mL (interquartile range 0.28-0.63). PSMA-avid disease was found in 66 patients (53%). Of these, 25 patients (38%) had PSMA-avid lesions found outside of the pelvis, 33 (50%) had lesions confined to the pelvic lymph nodes and prostate bed, and 8 (12%) men had PSMA-avid recurrence only in the prostate bed. Salvage radiation including standard Intensity Modulated Radiation Therapy (IMRT) pelvic nodal volumes would not cover PSMA-avid nodal disease in 38 men (30%). PSA at the time of imaging was statistically associated with having PSMA-avid disease outside of standard nodal fields (P <.01).

CONCLUSION

The 68Ga-PSMA-11 PET detects disease in a majority of patients with PSA ≤2.0 following RP. Nearly one-third of men had PSMA-avid disease that would be missed by standard radiation fields. This imaging modality may dramatically impact the design and use of post-RP salvage radiotherapy.

Postoperative elective pelvic nodal irradiation compared to prostate bed irradiation in locally advanced prostate cancer - a retrospective analysis of dose-escalated patients

Background

It is uncertain if whole-pelvic irradiation (WPRT) in addition to dose-escalated prostate bed irradiation (PBRT) improves biochemical progression-free survival (bPFS) after prostatectomy for locally advanced tumors. This study was initiated to analyze if WPRT is associated with bPFS in a patient cohort with dose-escalated (> 70 Gy) PBRT.

Methods

Patients with locally advanced, node-negative prostate carcinoma who had PBRT with or without WPRT after prostatectomy between 2009 and 2017 were retrospectively analyzed. A simultaneous integrated boost with equivalent-doses-in-2-Gy-fractions (EQD-2) of 79.29 Gy or 71.43 Gy to the prostate bed was applied in patients with margin-positive (or detectable) and margin-negative/undetectable tumors, respectively. WPRT (44 Gy) was offered to patients at an increased risk of lymph node metastases.

Results

Forty-three patients with PBRT/WPRT and 77 with PBRT-only were identified. Baseline imbalances included shorter surgery-radiotherapy intervals (S-RT-Intervals) and fewer resected lymph nodes in the WPRT group. WPRT was significantly associated with better bPFS in univariate (p = 0.032) and multivariate models (HR = 0.484, p = 0.015). Subgroup analysis indicated a benefit of WPRT (p = 0.029) in patients treated with rising PSA values who mostly had negative margins (74.1%); WPRT was not associated with a longer bPFS in the postoperative setting with almost exclusively positive margins (96.8%).

Conclusion

We observed a longer bPFS after WPRT compared to PBRT in patients with locally advanced prostate carcinoma who underwent dose-escalated radiotherapy. In subset analyses, the association was only observed in patients with rising PSA values but not in patients with non-salvage postoperative radiotherapy for positive margins.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1301-5) contains supplementary material, which is available to authorized users.

Elective pelvic irradiation in prostate cancer patients with biochemical failure following radical prostatectomy: A propensity score matching analysis

Purpose

To investigate whether whole pelvic radiotherapy (WPRT) improves biochemical relapse-free survival (bRFS) vs. prostate bed radiotherapy (PBRT) in prostate cancer patients receiving salvage radiotherapy (SRT) after radical prostatectomy.

Methods

Data from patients with prostate cancer who underwent SRT for biochemical recurrence between 2005 and 2012 in two academic institutions were retrospectively reviewed. Patients treated with WPRT in one hospital were compared with patients treated with PBRT in the other. Propensity scoring was performed to balance the characteristics of the different treatment groups, and bRFS was compared.

Results

Data from a total of 191 patients were included in the analysis (WPRT, n = 108; PBRT, n = 83). The median follow-up period was 66 months. Prior to matching, patients who received WPRT had higher pathologic Gleason scores as well as a higher incidence of pre-SRT PSA levels >0.5 ng/mL and lower rates of concurrent androgen-deprivation therapy. Propensity score matching balanced these characteristics and generated a cohort comprising 56 patients from each group. In the matched cohort, the 5 year bRFS of the WPRT group was significantly higher than that of the PBRT group (65.9 vs. 42.2%, p = 0.017). Multivariate analysis revealed that WPRT was an independent prognostic factor for bRFS (hazard ratio: 0.45, 95% confidence interval: 0.26–0.75, p = 0.002). This benefit of WPRT on bRFS was maintained in subgroup analyses, especially in patients with preoperative PSA level ≤20 ng/mL or pre-SRT PSA level ≥0.4 ng/mL.

Conclusions

These data suggest that, following radical prostatectomy, elective WPRT during SRT may improve bRFS compared with PBRT in selected patients. Patients with preoperative PSA level ≤20 ng/mL or pre-SRT PSA level ≥0.4 ng/mL represent a potential subgroup who benefit most from receiving WPRT. Results of prospective randomized trials are awaited to confirm this finding.

Hypofractionated postoperative helical tomotherapy in prostate cancer: a mono-institutional report of toxicity and clinical outcomes

Purpose

This is a mono-institutional study of acute and late toxicities and early biochemical control of a retrospective series of 75 prostate cancer patients treated with moderate postoperative hypofractionation delivered by helical tomotherapy (HT).

Patients and methods

From April 2013 to June 2017, 75 patients received adjuvant (n=37) or salvage (n=38) treatment, delivering to prostate bed a total dose of 63.8 Gy (equivalent dose in 2-Gy fractions=67.4 Gy) using 2.2 Gy fractions. Whole-pelvis irradiation was performed in 63% of cases (median dose, 49.3 Gy; range, 48–55.1 Gy). Concurrent hormonal therapy was administered in 46% of cases. Common Terminology Criteria for Adverse Events (version 4.0) was adopted for acute and late genitourinary (GU) and gastrointestinal (GI) toxicity evaluations. Biochemical progression was defined as PSA level increase of ≥0.2 or more above the postoperative radiotherapy (RT) nadir.

Results

Acute GU toxicities were as follows: G1 in 46% and G2 in 4%, detecting no G≥3 events. For GI toxicity, we recorded G1 in 36% and G2 in 18%. With a median follow-up of 30 months (range, 12–58 months), we found late toxicity G2 GI in 6.6% and G≥2 GU in 5.3%, including two patients who underwent surgical incontinence correction. Acute GI≥2 toxicity and diabetes were found to be predictive of late GI≥2 toxicity (P=0.04 and P=0.0019). Actuarial 2- and 3-year biochemical recurrence-free survivals were 88% and 73%, respectively, for the entire population.

Conclusion

In our experience, moderate hypofractionated postoperative RT with HT was feasible and safe, with reports of low incidence of toxicity and promising biochemical control rates.

Tailored postoperative treatment of prostate cancer: final results of a phase I/II trial

BACKGROUD

The European Organization for Research and Treatment of Cancer (EORTC) trial 22,911 reported 74% 5-year biochemical disease-free survival (bDFS) in patients with prostate carcinoma treated with radical prostatectomy (RP) followed by postoperative radiotherapy (RT). This study aimed to improve these outcomes by using a combined-intensified-modulated-adjuvant treatment, including RT and hormone therapy (HT) after RP.

MATERIALS AND METHODS

This phase I/II trial treatment was designed to improve 5-year bDFS from ~ 75 to 90%. Patients were consecutively enrolled using the following inclusion criteria: age < 80 years, histological diagnosis of prostate adenocarcinoma without known metastases, stage pT2-4N0-1, and Eastern Cooperative Oncology Group performance status of 0-2. All patients had at least one of these pathologic features: capsular perforation, positive surgical margins, seminal vesicle invasion, and pelvic lymph nodes involvement. A minimum dose of 64.8 Gy to the tumor bed was delivered in all patients. Depending on tumor characteristics at diagnosis, patients received a higher dose (70.2 Gy; 85.4%) and/or prophylactic pelvic lymph nodes irradiation (57.7%) and/or HT (69.1%). Biochemical relapse was defined as two consecutive rising prostate-specific antigen (PSA) values > 0.2 ng/ml.

RESULTS

A total of 123 patients were enrolled in the study and completed the scheduled treatment. Median preoperative and postoperative PSA were: 8.8 and 0.06 ng/mL, respectively. The percentages of patients with pathologically involved nodes and positive resection margins were: 14.6% and 58.5%, respectively. With a median follow-up of 67 months (range: 37-120 months), the actuarial 5-year bDFS, local control, metastasis-free survival, and overall survival (OS) were: 92.9%, 98.7%, 96.1%, and 95.1%, respectively.

CONCLUSION

A higher 5-year bDFS (92.9%) was recorded compared to studies based on standard adjuvant RT, even though patients with nodal disease and detectable postoperative PSA were enrolled. Clinical end points, as long-term disease-free survival and OS, will require further assessments. (ClinicalTrials.gov: NCT03169933).

Radiotherapy for recurrent prostate cancer: 2018 Recommendations of the Australian and New Zealand Radiation Oncology Genito-Urinary group

The management of patients with biochemical, local, nodal, or oligometastatic relapsed prostate cancer has become more challenging and controversial. Novel imaging modalities designed to detect recurrence are increasingly used, particularly PSMA-PET scans in Australia, New Zealand and some European countries. Imaging techniques such as MRI and PET scans using other prostate cancer-specific tracers are also being utilised across the world. The optimal timing for commencing salvage treatment, and the role of local and/or systemic therapies remains controversial. Through surveys of the membership, the Australian and New Zealand Faculty of Radiation Oncology Genito-Urinary Group (FROGG) identified wide variation in the management of recurrent prostate cancer. Following a workshop conducted in April 2017, the FROGG management committee reviewed the literature and developed a set of recommendations based on available evidence and expert opinion, for the appropriate investigation and management of recurrent prostate cancer. These recommendations cover the role and timing of post-prostatectomy radiotherapy, the management of regional nodal metastases and oligometastases, as well as the management of local prostate recurrence after definitive radiotherapy.

Contemporary role of postoperative radiotherapy for prostate cancer

While radical prostatectomy (RP) has provided long-term disease control for the majority of patients with localized prostate cancer (CaP), nearly 30% of all surgical patients have disease progression. For high-risk patients, more than half of men experience disease recurrence within 10 years. Postoperative radiotherapy is the only known potentially curative treatment for a large number of patients following prostatectomy. Lately, there have been several advances with the potential to improve outcomes for patients undergoing postoperative radiotherapy. This article will give an overview of the existing literature and current controversies on: (I) timing of postoperative radiation; (II) use of concomitant androgen deprivation therapy; (III) optimal dose to the prostate bed; (IV) use of hypofractionation; (V) elective treatment of the pelvic lymph nodes; (VI) novel imaging modalities, and (VII) genomic biomarkers.

Image-guided, whole-pelvic, intensity-modulated radiotherapy for biochemical recurrence following radical prostatectomy in high-risk prostate cancer patients

Background

The optimal field size of salvage radiotherapy (SRT) for biochemical recurrence, particularly for patients with high-risk prostate cancer, remains undefined. This retrospective analysis was performed to investigate oncological outcomes as well as treatment-related toxicity following salvage intensity-modulated radiotherapy (IMRT) to the whole pelvis and to compare the results with other studies implementing a small field size of the prostate bed.

Methods

The medical records of 170 patients with high-risk prostate cancer who received SRT for biochemical recurrence following prostatectomy were reviewed. Whole-pelvic IMRT was administered with a median dose of 66 Gy in 30 fractions. To improve treatment accuracy, an endorectal balloon device and daily cone-beam computed tomography were utilized. Androgen-deprivation therapy combined with SRT was administered to 97 (57.1%) patients.

Results

Eventually, 68 (40.0%) patients showed biochemical progression (BCP) after SRT. With a median follow-up period of 56 months, the 5-year BCP-free survival was 38.6%. The overall and cause-specific survival rates were 90.9% and 96.7%, respectively. Regarding BCP-free survival analysis, pathological T stage, persistent prostate-specific antigen (PSA) elevation after prostatectomy, and preSRT PSA level were significant prognostic factors on univariate analysis. On multivariate analysis, pathological T stage and preSRT PSA value retained their significance. Acute and late grade-3 genitourinary toxicities were observed in one (0.6%) and five (2.9%) patients, respectively. One patient each developed acute and late grade-3 gastrointestinal toxicity.

Conclusion

SRT to whole pelvis using IMRT and image guidance is as safe as SRT to the prostate bed, but its efficacy should be confirmed in ongoing randomized trials. PreSRT PSA was the only controllable prognostic factor, suggesting the benefit of early SRT.

Postoperative radiotherapy for prostate cancer : Morbidity of local-only or local-plus-pelvic radiotherapy

PURPOSE

The aim of this work was to characterise actuarial incidence and prevalence of early and late side effects of local versus pelvic three-dimensional conformal postoperative radiotherapy for prostate cancer.

MATERIALS AND METHODS

Based on a risk-adapted protocol, 575 patients received either local (n = 447) or local-plus-pelvic (n = 128) radiotherapy. Gastrointestinal (GI) and genitourinary (GU) side effects (≥grade 2 RTOG/EORTC criteria) were prospectively assessed. Maximum morbidity, actuarial incidence rate, and prevalence rates were compared between the two groups.

RESULTS

For local radiotherapy, median follow-up was 68 months, and the mean dose was 66.7 Gy. In pelvic radiotherapy, the median follow-up was 49 months, and the mean local and pelvic doses were 66.9 and 48.3 Gy respectively. Early GI side effects ≥ G2 were detected in 26% and 42% of patients respectively (p < 0.001). Late GI adverse events were detected in 14% in both groups (p = 0.77). The 5‑year actuarial incidence rates were 14% and 14%, while the prevalence rates were 2% and 0% respectively. Early GU ≥ G2 side effects were detected in 15% and 16% (p = 0.96), while late GU morbidity was detected in 18% and 24% (p = 0.001). The 5‑year actuarial incidence rates were 16% and 35% (p = 0.001), while the respective prevalence rates were 6% and 8%.

CONCLUSIONS

Despite the low prevalence of side effects, postoperative pelvic radiotherapy results in significant increases in the actuarial incidence of early GI and late GU morbidity using a conventional 4‑field box radiotherapy technique. Advanced treatment techniques like intensity-modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) should therefore be considered in pelvic radiotherapy to potentially reduce these side effects.

Salvage Radiotherapy for Biochemically Recurrent Prostate Cancer After Prostatectomy

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice. A 67-year-old man had presented to his primary physician for routine health maintenance. A digital rectal examination was performed and revealed a suspicious nodule in the right lobe of the prostate without any extraprostatic extension. A serum prostate-specific antigen (PSA) test was 12.4 ng/mL. He had no previous PSA tests. Transrectal ultrasound-guided prostate biopsy showed Gleason 3 + 4 prostate adenocarcinoma in seven of 12 cores. Bone scan and computed tomography scan of the pelvis showed no evidence of metastatic disease, and the patient underwent a robotic-assisted radical prostatectomy with bilateral pelvic lymphadenectomy. Pathology revealed Gleason 3 + 4 adenocarcinoma bilaterally, with extracapsular extension, no seminal vesicle invasion, a 2-mm positive margin at the right mid gland, and 0 of 15 lymph nodes containing adenocarcinoma. Two months after surgery, he had mild stress urinary incontinence and PSA of < 0.1 ng/mL. Adjuvant radiotherapy was discussed, but he elected to have careful follow-up. His PSA was monitored every 6 months and gradually increased from < 0.1 ng/mL to 0.4 ng/mL over the next 3 years. He was asymptomatic. He was referred to discuss the role of salvage radiotherapy.

Long-term Outcome of Prostate Cancer Patients Who Exhibit Biochemical Failure Despite Salvage Radiation Therapy After Radical Prostatectomy

OBJECTIVES

Salvage radiation therapy (SRT) is an effective treatment for recurrent prostate cancer (PCa) after radical prostatectomy. We report the long-term outcome of men who developed biochemical recurrence (BCR) after SRT and were treated >14 years ago.

METHODS

In total, 61 patients treated with SRT from 1992 to 2000 at our institution were identified. Survival was calculated by Kaplan-Meier method. Log-rank test and Cox regression were used to determine significance of clinical parameters.

RESULTS

The median follow-up was 126 months (interquartile range, 66-167 mo). Thirty-four (56%) had prostate-specific antigen (PSA) failure after SRT. At 10 years, overall survival (OS) was 67%, freedom from PSA failure (FFPF) was 33%, prostate cancer-specific survival (PCSS) was 84%, and distant metastases-free survival (DMFS) was 84%. Pathologic T-stage, Gleason score, seminal vesicle involvement, and pre-SRT PSA were associated with FFPF. For patients who failed SRT, the median time to BCR after SRT was 30 mo. A total of 19 (68%) received androgen deprivation therapy. The median OS was 13.6 years. At 10 years from time of BCR, OS was 59%, PCSS was 73%, DMFS was 75%, and castration-resistant-free survival was 70%. Early SRT failure correlated with significantly decreased DMFS and PCSS. Ten-year DMFS from SRT was 43% (BCR≤1 y) versus 91% (BCR>1 y).

CONCLUSIONS

Extended follow-up demonstrates that despite SRT failure, PCSS remains high in select patients. Early failure (≤1 y after SRT) predicted for significantly worse outcome and may represent a subgroup with more aggressive disease that may be considered for further prospective clinical studies.

Magnetic resonance imaging for prostate cancer before radical and salvage radiotherapy: What radiation oncologists need to know

External beam radiotherapy (EBRT) is one of the principal curative treatments for patients with prostate cancer (PCa). Risk group classification is based on prostate-specific antigen (PSA) level, Gleason score, and T-stage. After risk group determination, the treatment volume and dose are defined and androgen deprivation therapy is prescribed, if appropriate. Traditionally, imaging has played only a minor role in T-staging due to the low diagnostic accuracy of conventional imaging strategies such as transrectal ultrasound, computed tomography, and morphologic magnetic resonance imaging (MRI). As a result, a notable percentage of tumours are understaged, leading to inappropriate and imprecise EBRT. The development of multiparametric MRI (mpMRI), an imaging technique that combines morphologic studies with functional diffusion-weighted sequences and dynamic contrast-enhanced imaging, has revolutionized the diagnosis and management of PCa. As a result, mpMRI is now used in staging PCa prior to EBRT, with possible implications for both risk group classification and treatment decision-making for EBRT. mpMRI is also being used in salvage radiotherapy (SRT), the treatment of choice for patients who develop biochemical recurrence after radical prostatectomy. In the clinical context of biochemical relapse, it is essential to accurately determine the site of recurrence - pelvic (local, nodal, or bone) or distant - in order to select the optimal therapeutic management approach. Studies have demonstrated the value of mpMRI in detecting local recurrences - even in patients with low PSA levels (0.3-0.5 ng/mL) - and in diagnosing bone and nodal metastasis. The main objective of this review is to update the role of mpMRI prior to radical EBRT or SRT. We also consider future directions for the use and development of MRI in the field of radiation oncology.

Improving postoperative radiotherapy following radical prostatectomy

INTRODUCTION

Prostate cancer has one of the highest incidences in the world, with good curative treatment options like radiotherapy and radical prostatectomy. Unfortunately, about 30% of the patients initially treated with curative intent will develop a recurrence and need adjuvant treatment. Five randomized trials covered the role of postoperative radiotherapy after radical prostatectomy, but there is still a lot of debate about which patients should receive postoperative radiotherapy. Areas covered: This review will give an overview on the available literature concerning post-operative radiotherapy following radical prostatectomy with an emphasis on the five randomized trials. Also, new imaging techniques like prostate-specific membrane antigen positron emission tomography (PSMA-PET) and multiparametric magnetic resonance imaging (mp-MRI) and the development of biomarkers like genomic classifiers will be discussed in the search for an improved selection of patients who will benefit from postoperative radiotherapy following radical prostatectomy. With new treatment techniques like Intensity Modulated Radiotherapy, toxicity profiles will be kept low. Expert commentary: Patients with biochemical recurrence following radical prostatectomy with an early rise in prostate-specific antigen (PSA) will benefit most from postoperative radiotherapy. In this way, patients with only high risk pathological features can avoid unnecessary treatment and toxicity, and early intervention in progressing patients would not compromise the outcome.

Results of Dose-adapted Salvage Radiotherapy After Radical Prostatectomy Based on an Endorectal MRI Target Definition Model

OBJECTIVES

To assess the outcome of patients treated with a dose-adapted salvage radiotherapy (SRT) protocol based on an endorectal magnetic resonance imaging (erMRI) failure definition model after radical prostatectomy (RP).

METHODS

We report on 171 relapsing patients after RP who had undergone an erMRI before SRT. 64 Gy were prescribed to the prostatic bed with, in addition, a boost of 10 Gy to the suspected local relapse as detected on erMRI in 131 patients (76.6%).

RESULTS

The 3-year biochemical relapse-free survival (bRFS), local relapse-free survival, distant metastasis-free survival, cancer-specific survival, and overall survival were 64.2±4.3%, 100%, 85.2±3.2%, 100%, and 99.1±0.9%, respectively. A PSA value >1 ng/mL before salvage (P=0.006) and an absence of biochemical progression during RT (P=0.001) were both independently correlated with bRFS on multivariate analysis. No significant difference in 3-year bRFS was observed between the boost and no-boost groups (68.4±4.6% vs. 49.7±10%, P=0.251).

CONCLUSIONS

A PSA value >1 ng/mL before salvage and a biochemical progression during RT were both independently correlated with worse bRFS after SRT. By using erMRI to select patients who are most likely expected to benefit from dose-escalated SRT protocols, this dose-adapted SRT approach was associated with good biochemical control and outcome, serving as a hypothesis-generating basis for further prospective trials aimed at improving the therapeutic ratio in the salvage setting.

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.

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.

Impact of 68Ga-PSMA PET/CT on salvage radiotherapy planning in patients with prostate cancer and persisting PSA values or biochemical relapse after prostatectomy

BACKGROUND

Salvage radiotherapy (SRT) is clinically established in prostate cancer (PC) patients with PSA persistence or biochemical relapse (BCR) after prior radical surgery. PET/CT imaging prior to SRT may be performed to localize disease recurrence. The recently introduced 68Ga-PSMA outperforms other PET tracers for detection of recurrence and is therefore expected also to impact radiation planning. Forty-five patients with PSA persistence (16 pts) or BCR (29 pts) after prior prostatectomy, scheduled to undergo SRT of the prostate bed, underwent 68Ga-PSMA PET/CT. The median PSA level was 0.67 ng/ml. The impact of 68Ga-PSMA PET/CT on the treatment decision was assessed. Patients with oligometastatic (≤5 lesions) PC underwent radiotherapy (RT), with the extent of the RT area and dose escalation being based on PET positivity.

RESULTS

Suspicious lesions were detected in 24/45 (53.3 %) patients. In 62.5 % of patients, lesions were only detected by 68Ga-PSMA PET. Treatment was changed in 19/45 (42.2 %) patients, e.g., extending SRT to metastases (9/19), administering dose escalation in patients with morphological local recurrence (6/19), or replacing SRT by systemic therapy (2/19). 38/45 (84.4 %) followed the treatment recommendation, with data on clinical follow-up being available in 21 patients treated with SRT. All but one showed biochemical response (mean PSA decline 78 ± 19 %) within a mean follow-up of 8.12 ± 5.23 months.

CONCLUSIONS

68Ga-PSMA PET/CT impacts treatment planning in more than 40 % of patients scheduled to undergo SRT. Future prospective studies are needed to confirm this significant therapeutic impact on patients prior to SRT.

A Urologist's Personal View of Prostate Cancer

A urologist's personal experience with multiple surgical, hormonal, and radio/immunotherapeutic options for the treatment of advanced prostate cancer and thoughts on the role of old and new therapies.

Contemporary Mapping of Post-Prostatectomy Prostate Cancer Relapse with 11C-Choline Positron Emission Tomography and Multiparametric Magnetic Resonance Imaging

PURPOSE

We identify sites and patterns of cancer recurrence in patients with post-prostatectomy biochemical relapse using ¹¹C-choline positron emission tomography/computerized tomography and endorectal coil multiparametric magnetic resonance imaging.

MATERIALS AND METHODS

Between January 2008 and June 2015, 2,466 men underwent choline positron emission tomography for suspected prostate cancer relapse at our institution. Of these men 202 did not receive hormone or radiation therapy, underwent imaging with choline positron emission tomography and multiparametric magnetic resonance imaging, and were found to have disease recurrence. Overall patterns of recurrence were described, and factors associated with local only recurrence were evaluated using univariable and multivariable logistic regression.

RESULTS

Median prostate specific antigen at positive scan was 2.3 ng/ml (IQR 1.4-5.5) with a median time from prostate specific antigen relapse to lesion visualization of 15 months (IQR 4.8-34.2). Of these 202 men 68 (33%) exhibited local only, 45 (22%) local plus metastatic and 89 (45%) metastatic only relapse. Pelvic node only relapse was observed in 39 (19%) men. Median prostate specific antigen at positive imaging for patients with local only, metastatic only and local plus metastatic relapse was 2.3, 2.7 and 2.2 ng/ml (p=0.46), with a median interval from biochemical recurrence to positive scan of 33.5, 7.0 and 15.0 months, respectively (p <0.001). On multivariable analysis time from biochemical recurrence to positive imaging was independently associated with local only recurrence (OR 1.10 for every 6-month increase, p=0.012).

CONCLUSIONS

Combined choline positron emission tomography and multiparametric magnetic resonance imaging evaluation of biochemical recurrence after prostatectomy reveals an anatomically diverse pattern of recurrence. These findings have implications for optimizing the salvage treatment of patients with prostate cancer with relapse following surgery.

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.

A prospective comparison of acute intestinal toxicity following whole pelvic versus small field intensity-modulated radiotherapy for prostate cancer

Purpose

To compare the acute intestinal toxicity of whole pelvic (WP) and small field (SF) intensity-modulated radiotherapy (IMRT) for prostate cancer using dosimetric and metabolic parameters as well as clinical findings.

Methods

Patients who received IMRT in either a definitive or postoperative setting were prospectively enrolled. Target volume and organs at risk including intestinal cavity (IC) were delineated in every patient by a single physician. The IC volume that received a 10–50 Gy dose at 5-Gy intervals (V10–V50) and the percentage of irradiated volume as a fraction of total IC volume were calculated. Plasma citrulline levels, as an objective biological marker, were checked at three time points: baseline and after exposure to 30 Gy and 60 Gy.

Results

Of the 41 patients, only six experienced grade 1 acute intestinal toxicity. Although all dose–volume parameters were significantly worse following WP than SF IMRT, there was no statistically significant relationship between these dosimetric parameters and clinical symptoms. Plasma citrulline levels did not show a serial decrease by radiotherapy volume difference (WP versus SF) and were not relevant to the irradiated doses.

Conclusion

Given that WP had comparable acute intestinal toxicities to those associated with SF, WP IMRT appears to be a feasible approach for the treatment of prostate cancer despite dosimetric disadvantages.

Pelvic MRI findings in relapsed prostate cancer after radical prostatectomy

PURPOSE/OBJECTIVE

Little is known about the clinical impact of using multiparametric MRI to plan early salvage radiotherapy after radical prostatectomy. We aimed to evaluate the incidence and location of recurrence based on pelvic multiparametric MRI findings and to identify clinical variables predictive of positive imaging results.

MATERIALS AND METHODS

We defined radiological criteria of local and lymph node malignancy and reviewed records and MRI studies of 70 patients with PSA recurrence after radical prostatectomy. We performed univariate and multivariate analysis to identify any association between clinical, pathological and treatment-related variables and imaging results.

RESULTS

Multiparametric MRI was positive in 33/70 patients. We found local and lymph node recurrence in 27 patients and 7 patients, respectively, with a median PSA value of 0.38 ng/ml. We found no statistically significant differences between patients with positive and negative multiparametric MRI for any variable. Shorter PSADT was associated with positive lymph nodes (median PSADT: 5.12 vs 12.70 months; p: 0.017).

CONCLUSIONS

Nearly half the patients had visible disease in multiparametric MRI despite low PSA. Positive lymph nodes incidence should be considered when planning salvage radiotherapy, particularly in patients with a short PSADT.

Dose-volume effects for pelvic bone marrow in predicting hematological toxicity in prostate cancer radiotherapy with pelvic node irradiation

PURPOSE

To prospectively identify clinical/dosimetric predictors of acute/late hematologic toxicity (HT) in chemo-naÏve patients treated with whole-pelvis radiotherapy (WPRT) for prostate cancer.

MATERIAL AND METHODS

Data of 121 patients treated with adjuvant/salvage WPRT were analyzed (static-field IMRT n=19; VMAT/Rapidarc n=57; Tomotherapy n=45). Pelvic bone marrow (BM) was delineated as ilium (IL), lumbosacral, lower and whole pelvis (WP), and the relative DVHs were calculated. HT was graded both according to CTCAE v4.03 and as variation in percentage relative to baseline. Logistic regression was used to analyze association between HT and clinical/DVHs factors.

RESULTS

Significant differences (p<0.005) in the DVH of BM volumes between different techniques were found: Tomotherapy was associated with larger volumes receiving low doses (3-20 Gy) and smaller receiving 40-50 Gy. Lower baseline absolute values of WBC, neutrophils and lymphocytes (ALC) predicted acute/late HT (p ⩽ 0.001). Higher BM V40 was associated with higher risk of acute Grade3 (OR=1.018) or late Grade2 lymphopenia (OR=1.005). Two models predicting lymphopenia were developed, both including baseline ALC, and BM WP-V40 (AUC=0.73) and IL-V40+smoking (AUC=0.904) for acute/late respectively.

CONCLUSIONS

Specific regions of pelvic BM predicting acute/late lymphopenia, a risk factor for viral infections, were identified. The 2-variable models including specific constraints to BM may help reduce HT.

Quality of Life after Post-Prostatectomy Intensity Modulated Radiation Therapy: Pelvic Nodal Irradiation Is Not Associated with Worse Bladder, Bowel, or Sexual Outcomes

Background

Limited data exist regarding toxicity and quality of life (QOL) after post-prostatectomy intensity modulated radiation therapy (IMRT) and whether pelvic nodal RT influences these outcomes.

Methods

118 men were treated with curative-intent RT after radical prostatectomy. 69 men (58%) received pelvic nodal RT. QOL data and physician-assigned toxicity were prospectively collected. Changes in QOL from baseline were assessed with Wilcoxon signed-rank tests and risk factors associated with each domain were identified with generalized estimating equation (GEE) models. Late freedom from (FF) toxicity was estimated by the Kaplan-Meier method and comparisons were tested using the log-rank test.

Results

Urinary irritation/obstruction, bowel, and sexual domain scores declined at 2 months (all P ≤ 0.01) but were no different than baseline at subsequent visits through 4 years of follow-up. At 4 years, FF grade 2+ GI toxicity was 90% and FF grade 2+ GU toxicity was 89%. On GEE analysis, pelvic nodal RT was associated with decreased bowel function (P = 0.09) and sexual function (P = 0.01). On multivariate analysis, however, there was no significant association with either decreased bowel (P = 0.31) or sexual (P = 0.84) function. There was also no association with either FF grade 2+ GI toxicity (P = 0.24) or grade 2+ GU toxicity (P = 0.51).

Conclusions

Receipt of pelvic nodal RT was not associated with inferior QOL or toxicity compared to prostate bed alone RT. For the entire cohort, RT was associated with only temporary declines in patient-reported urinary, bowel, or sexual QOL.

Survival Outcomes of Whole-Pelvic Versus Prostate-Only Radiation Therapy for High-Risk Prostate Cancer Patients With Use of the National Cancer Data Base

PURPOSE/OBJECTIVES

The addition of whole pelvic (WP) compared with prostate-only (PO) radiation therapy (RT) for clinically node-negative prostate cancer remains controversial. The purpose of our study was to evaluate the survival benefit of adding WPRT versus PO-RT for high-risk, node-negative prostate cancer, using the National Cancer Data Base (NCDB).

METHODS AND MATERIALS

Patients with high-risk prostate cancer treated from 2004 to 2006, with available data for RT volume, coded as prostate and pelvis (WPRT) or prostate alone (PO-RT) were included. Multivariate analysis (MVA) and propensity-score matched analysis (PSM) were performed. Recursive partitioning analysis (RPA) based on overall survival (OS) using Gleason score (GS), T stage, and pretreatment prostate-specific antigen (PSA) was also conducted.

RESULTS

A total of 14,817 patients were included: 7606 (51.3%) received WPRT, and 7211 (48.7%) received PO-RT. The median follow-up time was 81 months (range, 2-122 months). Under MVA, the addition of WPRT for high-risk patients had no OS benefit compared with PO-RT (HR 1.05; P=.100). On subset analysis, patients receiving dose-escalated RT also did not benefit from WPRT (HR 1.01; P=.908). PSM confirmed no survival benefit with the addition of WPRT for high-risk patients (HR 1.05; P=.141). In addition, RPA was unable to demonstrate a survival benefit of WPRT for any subset. Other prognostic factors for inferior OS under MVA included older age (HR 1.25; P<.001), increasing comorbidity scores (HR 1.46; P<.001), higher T stage (HR 1.17; P<.001), PSA (HR 1.81; P<.001), and GS (HR 1.29; P<.001), and decreasing median county household income (HR 1.15; P=.011). Factors improving OS included the addition of androgen deprivation therapy (HR 0.92; P=.033), combination external beam RT plus brachytherapy boost (HR 0.71; P<.001), and treatment at an academic/research institution (HR 0.84; P=.002).

CONCLUSION

In the largest reported analysis of WPRT for patients with high-risk prostate cancer treated in the dose-escalated era, the addition of WPRT demonstrated no survival advantage compared with PO-RT.

Postoperative radiation therapy for patients at high-risk of recurrence after radical prostatectomy: does timing matter?

OBJECTIVE

To evaluate among radical prostatectomy (RP) patients at high-risk of recurrence whether the timing of postoperative radiation therapy (RT) (adjuvant, early salvage with detectable post-RP prostate-specific antigen [PSA], or 'late' salvage with a PSA level of >1.0 ng/mL) is significantly associated with overall survival (OS), prostate-cancer specific survival or metastasis-free survival, in a longitudinal cohort.

PATIENTS AND METHODS

Of 6 176 RP patients in the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), 305 patients with high-risk pathological features (margin positivity, Gleason score 8-10, or pT3-4) who underwent postoperative RT were examined, either in the adjuvant (≤6 months after RP with undetectable PSA levels, 76 patients) or salvage setting (>6 months after RP or pre-RT PSA level of >0.1 ng/mL, 229 patients). Early (PSA level of ≤1.0 ng/mL, 180 patients) or late salvage RT (PSA level >1.0 ng/mL, 49 patients) was based on post-RP, pre-RT PSA level. Multivariable Cox regression examined associations with all-cause mortality and prostate cancer-specific mortality and/or metastases (PCSMM).

RESULTS

After a median of 74 months after RP, 65 men had died (with 37 events of PCSMM). Adjuvant and salvage RT patients had comparable high-risk features. Compared with adjuvant, salvage RT (early or late) had an increased association with all-cause mortality (hazard ratio [HR] 2.7, P = 0.018) and with PCSMM (HR 4.0, P = 0.015). PCSMM-free survival differed by further stratification of timing, with 10-year estimates of 88%, 84%, and 71% for adjuvant, early salvage, and late salvage RT, respectively (P = 0.026). For PCSMM-free survival and OS, compared with adjuvant RT, late salvage RT had statistically significantly increased risk; however, early salvage RT did not.

CONCLUSION

This analysis suggests that patients who underwent early salvage RT with PSA levels of <1.0 ng/mL may have comparable metastasis-free survival and OS compared with adjuvant RT; however, late salvage RT with a PSA level of >1.0 ng/mL is associated with worse clinical outcomes.

Dosimetric effects of the acuros XB and anisotropic analytical algorithm on volumetric modulated arc therapy planning for prostate cancer using an endorectal balloon

BACKGROUND

To compare the dosimetric effects of Acuros XB (AXB) and Anisotropic Analytical Algorithm (AAA) on volumetric modulated arc therapy (VMAT) planning for postoperative prostate cancer patients irradiated using an endorectal balloon (ERB).

METHODS

We measured central axis doses with film in a phantom containing an air cavity, and compared measurements with calculations of the AAA and AXB. For clinical study, 10 patients who had undergone whole pelvic radiotherapy (WPRT) followed by prostatic bed-only radiotherapy (PBRT) using VMAT were enrolled. An ERB was used for PBRT but not for WPRT. To compare dosimetric parameters, the cumulative dose-volume histograms, mean, maximum, and minimum doses were measured for the planning target volume. Homogeneity of plans were confirmed using V95%, V107% (VX%, percentage volumes receiving at least X% of prescribed doses) and conformity indices (homogeneity index [HI], conformity index [CI], and conformation number [CN]). We compared volumes of the organ-at-risk receiving 10% to 100% (10-tier at 10% interval) of prescribed doses (V10% - V100%).

RESULTS

In the phantom study, the AAA showed larger disagreement with the measurements, and overestimated the dose in the air cavity, comparing with the AXB. For WPRT planning, the AAA predicted a lower maximum dose and V107% than the AXB. For PBRT planning, the AAA estimated a higher minimum dose, lower maximum dose, and smaller V107%, and larger V95% than the AXB. Regarding the conformity indices, the AAA was estimated to be more homogenous than the AXB for PBRT planning (HI, 0.088 vs. 0.120, p = 0.005; CI, 1.052 vs. 1.038, p = 0.022; and CN, 0.920 vs. 0.900, p = 0.007) but not for WPRT planning. Among V10% to V100% of the rectum, the PBRT exhibited significant discrepancies in V30%, V40%, V70%, V80%, and V90%; while the WPRT did in V20% and V30%.

CONCLUSIONS

The phantom study demonstrated that the AXB calculates more accurately in the air cavity than the AAA. In the clinical setting, the AXB exhibited different dosimetric distributions in the VMAT plans for PBRT containing an ERB. The AXB should be considered for prostate cancer patients irradiated with an ERB for better applying of heterogeneous condition.