Salvage radiotherapy following radical prostatectomy

Prostate Cancer Recurrence: Examining the Role of Salvage Radiotherapy Field and Risk Factors for Regional Disease Recurrence Captured on 18F-DCFPyL PET/CT

PURPOSE

The role of elective pelvic nodal irradiation in salvage radiotherapy (sRT) remains controversial. Utilizing 18F-DCFPyL PET/CT, this study aimed to investigate differences in disease distribution after whole pelvic (WPRT) or prostate bed (PBRT) radiotherapy and to identify risk factors for pelvic lymph node (LN) relapse.

METHODS

This retrospective study included patients with PSA > 0.1 ng/mL post-radical prostatectomy (RP) or post-RP and sRT who underwent 18F-DCFPyL PET/CT. Disease distribution on 18F-DCFPyL PET/CT after sRT was compared using Chi-square tests. Risk factors were tested for association with pelvic LN relapse after RP and salvage PBRT using logistic regression.

RESULTS

979 18F-DCFPyL PET/CTs performed at our institution between 1/1/2022 - 3/24/2023 were analyzed. There were 246 patients meeting criteria, of which 84 received salvage RT after RP (post-salvage RT group) and 162 received only RP (post-RP group). Salvage PBRT patients (n = 58) had frequent pelvic nodal (53.6%) and nodal-only (42.6%) relapse. Salvage WPRT patients (n = 26) had comparatively lower rates of pelvic nodal (16.7%, p = 0.002) and nodal-only (19.2%, p = 0.04) relapse. The proportion of distant metastases did not differ between the two groups. Multiple patient characteristics, including ISUP grade and seminal vesicle invasion, were associated with pelvic LN disease in the post-RP group.

CONCLUSION

At PSA persistence or progression, salvage WPRT resulted in lower rates of nodal involvement than salvage PBRT, but did not reduce distant metastases. Certain risk factors increase the likelihood of pelvic LN relapse after RP and can help inform salvage RT field selection.

Quality of Radiation Therapy Referral and Utilisation Post-prostatectomy: A Population-based Study of Time Trends

AIMS

Adjuvant radiotherapy post-prostatectomy has been shown to benefit patients with adverse pathology. It remains unclear whether salvage radiotherapy confers equivalent outcomes. Practice guidelines recommend referral to radiation oncology within 6 months after prostatectomy to discuss adjuvant and salvage radiotherapy. The study objectives were to assess, at a population level: (i) post-prostatectomy referral patterns for radiotherapy; (ii) adjuvant and salvage radiotherapy utilisation; and (iii) time trends in relation to clinical trials and guidelines. These findings provide indications of access to quality care.

MATERIALS AND METHODS

This was a retrospective cohort study. Electronic radiotherapy consultation and treatment records were linked to the population-based Ontario Cancer Registry. The population included prostate cancer cases treated with prostatectomy in Ontario between 2003 and 2012. Radiotherapy referral and treatment rates over time were analysed using the chi-squared trend test.

RESULTS

Over the study period, 30 447 prostate cancer patients received prostatectomy. The proportion seen by radiation oncology within 6 months after prostatectomy doubled from 10.7% in 2003-2004 to 21.7% in 2011-2012 (P < 0.0001 for trend), with the largest annual percentage difference in 2009-2011 (3.4%). Among 4641 patients seen within 6 months, adjuvant radiotherapy rates remained at 51.0% ± 3.0%. Contemporaneous with radiation oncology referral trends, overall adjuvant radiotherapy use increased from 6.2% in 2003-2004 to 11.0% in 2011-2012 (P < 0.001), while salvage radiotherapy remained at 8.4% ± 0.4%. Consequently, the total proportion receiving radiotherapy within 24 months increased from 14.1% in 2003-2004 to 17.7% in 2009-2010 (P < 0.0001).

CONCLUSIONS

There was an increase in access to early radiation oncology referral post-prostatectomy and adjuvant radiotherapy in Ontario between 2003 and 2012, following guideline publication.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

High-intensity focused ultrasound therapy for prostate cancer

Recent advances in high-intensity focused ultrasound, which was developed in the 1940s as a viable thermal tissue ablation approach, have increased its popularity. High-intensity focused ultrasound is currently utilized the most in Europe and Japan, but has not yet been approved by the Food and Drug Administration, USA, for this indication. The purpose of the present report is to review the scientific foundation of high-intensity focused ultrasound technology and the clinical outcomes achieved with commercially available devices. Recently published articles were reviewed to evaluate the current status of high-intensity focused ultrasound as a primary or salvage treatment option for localized prostate cancer. Improvements in the clinical outcome as a result of technical, imaging and technological advancements are described herein. A wide range of treatment options for organ-confined prostate cancer is available. However, high-intensity focused ultrasound is an attractive choice for men willing to choose less invasive options, although establishing the efficacy of high-intensity focused ultrasound requires longer follow-up periods. Technological advances, together with cultural and economic factors, have caused a dramatic shift from traditional open, radical prostatectomy to minimally invasive techniques. High-intensity focused ultrasound is likely to play a significant role in the future of oncology practice.

HIFU as salvage first-line treatment for palpable, TRUS-evidenced, biopsy-proven locally recurrent prostate cancer after radical prostatectomy: a pilot study

OBJECTIVE

To test high-intensity focused ultrasound (HIFU) as salvage first-line treatment for palpable, TRUS-evidenced, biopsy-proven locally recurrent prostate cancer (CaP) after radical prostatectomy (RP).

MATERIALS AND METHODS

Nineteen patients with palpable, TRUS-evidenced, biopsy-proven local recurrence of CaP after RP, unwilling to undergo salvage radiotherapy (SRT), underwent HIFU as a single-session procedure. Pre-, intra-, and postoperative data including early and late complications, and oncologic outcomes (PSA nadir, biochemical recurrence (BCR)-free survival, and need of secondary adjuvant treatment) were prospectively evaluated. Success was defined as PSA nadir ≤0.1 ng/ml obtained within 3 months from HIFU. In case of PSA nadir >0.1 ng/ml or PSA increase ≥1 ng/ml above the PSA nadir, a biopsy of the treated lesion was performed, and if negative, maximum androgen blockade (MAB) was adopted. In case of positive biopsy, RT was performed. Failure was defined as use of secondary adjuvant treatment (MAB or RT).

RESULTS

Median follow-up was 48 months. All cases were performed as overnight procedure. No case of urethrorectal fistula or anastomotic stricture was observed. Two cases of acute urinary retention were resolved with prolonged urethral catheterization. Four cases of stress urinary incontinence were observed; 2 (mild incontinence) were resolved after pelvic floor exercises within 6 months, while 2 cases of severe incontinence required surgical minimally invasive treatment;17/19 patients (89,5%) were classified as success. Two patients failed to show a PSA nadir <0.1 ng/ml. During follow-up, 8/17 patients (47%) were classified as failure, with consequent total rate of failures 10/19 (52.6%). A statistically significant difference was observed in pre-HIFU median PSA (2 vs. 5.45 ng/ml, respectively, P = 0.013) and Gleason score of the RP specimen (P = 0.01) between the success and failure group.

CONCLUSIONS

Salvage first-line HIFU for palpable, TRUS-evidenced, biopsy-proven local recurrence of CaP is a feasible, minimally invasive day-case procedure, with an acceptable morbidity profile. It seems to have a good cancer control in the short- and mid-term. Patients with lower pre-HIFU PSA level and favorable pathologic Gleason score presented better oncologic outcomes. A prospective randomized trial with an adequate recruitment and follow-up is necessary to confirm our preliminary oncologic results.

Acute myeloid leukemia incidence following radiation therapy for localized or locally advanced prostate adenocarcinoma

INTRODUCTION

The effect of radiation therapy on acute myeloid leukemia incidence among prostate cancer patients has not been sufficiently elucidated despite evidence that acute myeloid leukemia is a consequence of therapeutic radiation in other primary malignancies. Therefore, we investigated the effect of definitive therapy with radiation therapy (external beam radiation therapy [EBRT] or brachytherapy) on acute myeloid leukemia incidence in a population-based cohort of patients with localized or locally advanced prostate cancer.

METHODS

We utilized the Surveillance, Epidemiology, and End Results database to identify a cohort of men (n=168,612) with newly diagnosed prostate adenocarcinoma between January 1988 and December 2003. Cox proportional hazard regression was used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of acute myeloid leukemia incidence following definitive therapy with EBRT alone, brachytherapy alone, or surgery alone compared to no definitive therapy (i.e. no EBRT, brachytherapy, or surgery).

RESULTS

The cohort yielded 184 acute myeloid leukemia cases during 1,064,820 person-years of follow-up after prostate adenocarcinoma diagnosis. Patients treated with EBRT had a higher adjusted relative risk of developing acute myeloid leukemia than patients treated with brachytherapy or surgery when each therapy group was compared to patients who were not treated with definitive therapy (EBRT: HR=2.05, 95% CI 1.29, 3.26; brachytherapy: HR=1.22, 95% CI 0.46, 3.22; surgery: HR=1.24, 95% CI 0.77, 1.98).

CONCLUSIONS

Our findings suggest that acute myeloid leukemia incidence is a greater concern for patients treated with EBRT than brachytherapy for localized or locally advanced prostate adenocarcinoma.

Impact of anatomical interventions on the localization of post-prostatectomy cancer patients

PURPOSE

Anatomical deformations of prostate-bed, rectum, and bladder can compromise the targeting accuracy in post-prostatectomy cancer patients. In this work, the impact of anatomical interventions on the localization data from post-prostatectomy patients who received image-guided IMRT was analyzed.

METHODS

Patients were localized daily with online kilovoltage cone-beam computed tomography (kV-CBCT). The target and the organs at risk (OARs) positional and volumetric changes were evaluated and couch shifts were applied. For patients with large target or OAR volumetric changes, quantified by either a rectal or bladder wall displacement of >5 mm on the CBCT sagittal images compared to the planning CT, repeated localization CBCT scans were performed following an interventional procedure. The procedure involves insertion of a catheter to deflate the rectum, evacuation of stools, and/or adjustment of bladder filling. The required shifts were then evaluated, and the IMRT treatment was subsequently delivered after proper patient positioning. The pre- and post-intervention shifts were compared in the lateral [left-right (LR)], longitudinal [superior-inferior (SI)], and vertical [anterior-posterior (AP)] directions. The percentage of shifts larger than 5 mm in all directions was also compared. Clinical target volume to planning target volume (CTV-to-PTV) expansion margins were estimated based on the pre- and post-intervention localization data.

RESULTS

Intervention was performed on all patients (n=17) treated between October 2008 and March 2009. The number of interventions ranged from 2 to 12 with a median number of 5, resulting in a total of 96 pairs of pre- and post-intervention shifts. The mean value (sigma) and standard deviation (sigma) of the shifts from pre- versus post-intervention data were LR, 0.0 +/- 3.0 mm vs. 0.5 +/- 2.8 mm; SI, 0.2 +/- 3.1 mm vs. -1.0 +/- 2.1 mm; and AP, -2.6 +/- 5.8 mm vs. 1.7 +/- 3.9 mm. The mean 3D shift distance was 7.0 +/- 3.1 mm vs. 5.0 +/- 2.6 mm. The percentage of pre-intervention shifts larger than 5 mm were 7%, 7%, and 45% in the LR, SI, and AP directions, respectively, compared to 8%, 4%, and 21% for post-intervention. Localization data from pre- and post-intervention procedures suggest that treatments that do not include intervention to correct for rectum/bladder anatomical variations require an additional 3.3 mm CTV-to-PTV margin.

CONCLUSIONS

Anatomical interventions reduced the localization errors arising from large volume and shape changes in the rectum and/or bladder compared to treatments without interventions.

Salvage high-intensity focused ultrasound for biopsy-confirmed local recurrence of prostate cancer after radical prostatectomy

OBJECTIVE

To present experience in high-intensity focused ultrasound (HIFU) used as a salvage therapy for biopsy-confirmed local recurrence at the vesico-urethral anastomosis after radical prostatectomy (RP).

PATIENTS AND METHODS

From July 2006, four patients diagnosed with prostate cancer recurrence after RP were treated with HIFU, with or without salvage radiotherapy, using the Sonablate 500 (Focus Surgery, IN, USA). Biochemical failure was defined as in increase in prostate-specific antigen (PSA) level of >0.2 ng/mL. No patients received any adjuvant therapy after HIFU therapy before reporting failure.

RESULTS

The mean age and initial PSA level before RP was 74 years and 10.0 ng/mL, respectively. After RP, one patient was stage T2aN0M0, two were stage T3N0M0 and the last had an unknown pathological stage. Three patients received external beam radiotherapy as salvage therapy after RP. The mean PSA level before HIFU, tumour volume at the vesico-urethral lesion and operative duration were 4.3 ng/mL, 4.6 mL and 27 min, respectively. Adenocarcinomas were confirmed by biopsy of the tumour at the vesico-urethral anastomotic lesion before HIFU. At 24 months of follow-up, patients 2 and 4 were classified a biochemically disease-free. Biopsies at the anastomotic site after HIFU in three patients showed no malignancy, with fibrosis. There were no complications.

CONCLUSION

Salvage HIFU for patients with recurrence after RP is feasible, even though they received salvage radiotherapy before HIFU. More patients and a longer follow-up are needed to evaluate the safety and oncological adequacy of this new approach.