Salvage Low Dose Rate Brachytherapy For Recurrent Prostate Cancer After External Beam Radiotherapy: Results From A Single Institution With Focus On Toxicity And Functional Outcomes

Linac-based stereotactic salvage reirradiation for intraprostatic prostate cancer recurrence: toxicity and outcomes

BACKGROUND

The rates of local failure after curative radiotherapy for prostate cancer (PC) remain high despite more accurate locoregional treatments available, with one third of patients experiencing biochemical failure and clinical relapse occurring in 30-47% of cases. Today, androgen deprivation therapy (ADT) is the treatment of choice in this setting, but with not negligible toxicity and low effects on local disease. Therefore, the treatment of intraprostatic PC recurrence represents a challenge for radiation oncologists. Prostate reirradiation (Re-I) might be a therapeutic possibility. We present our series of patients treated with salvage stereotactic Re‑I for intraprostatic recurrence of PC after radical radiotherapy, with the aim of evaluating feasibility and safety of linac-based prostate Re‑I.

MATERIALS AND METHODS

We retrospectively evaluated toxicities and outcomes of patients who underwent salvage reirradiation using volumetric modulated arc therapy (VMAT) for intraprostatic PC recurrence. Inclusion criteria were age ≥ 18 years, histologically proven diagnosis of PC, salvage Re‑I for intraprostatic recurrence after primary radiotherapy for PC with curative intent, concurrent/adjuvant ADT with stereotactic body radiation therapy (SBRT) allowed, performance status ECOG 0-2, restaging choline/PSMA-PET/TC and prostate MRI after biochemical recurrence, and signed informed consent.

RESULTS

From January 2019 to April 2022, 20 patients were recruited. Median follow-up was 26.7 months (range 7-50). After SBRT, no patients were lost at follow-up and all are still alive. One- and 2‑year progression free survival (PFS) was 100% and 81.5%, respectively, while 2‑year biochemical progression-free survival (bFFS) was 88.9%. Four patients (20%) experienced locoregional lymph node progression and were treated with a further course of SBRT. Prostate reirradiation allowed the ADT start to be postponed for 12-39 months. Re‑I was well tolerated by all patients and none discontinued the treatment. No cases of ≥ G3 genitourinary (GU) or gastrointestinal (GI) toxicity were reported. Seven (35%) and 2 (10%) patients experienced acute G1 and G2 GU toxicity, respectively. Late GU toxicity was recorded in 10 (50%) patients, including 8 (40%) G1 and 2 (10%) G2. ADT-related side effects were found in 7 patients (hot flashes and asthenia).

CONCLUSION

Linac-based SBRT is a safe technique for performing Re‑I for intraprostatic recurrence after primary curative radiotherapy for PC. Future prospective, randomized studies are desirable to better understand the effectiveness of reirradiation and the still open questions in this field.

Outcomes and toxicities of re-irradiation for prostate cancer: A systematic review on behalf of the Re-Irradiation Working Group of the Italian Association of Radiotherapy and Clinical Oncology (AIRO)

AIMS

The best therapeutic approach for local relapses of previously irradiated prostate cancer (PC) is still not defined. Re-irradiation (Re-I) could offer a chance of cure for highly selected patients, although high quality evidences are lacking. The aim of our study is to provide a literature review on efficacy and safety of Re-I.

METHODS

Only studies where Re-I field overlaps with previous radiotherapy were considered. To determine 2 and 4 years overall mortality (OM), 2 and 4 years biochemical failure (BF) and pooled acute and late G ≥ 3 toxicities rate, a meta-analysis over single arm study was performed.

RESULTS

Thirty-eight studies with 1194 patients were included. Median follow-up from Re-I was 30 months (10-94 months). Brachytherapy (BRT) was the most used Re-I technique (27 studies), followed by Stereotactic Body Radiotherapy (SBRT) (9) and External Beam Radiation Therapy (EBRT) (2). Re-I prescription doses ranged from 19 Gy in single HDR fraction to 145 Gy (interstitial BRT). The pooled 2 and 4 years OM rates were 2.1% (95%CI:1.1-3.7%, P < 0.001) and 12.5% (95%CI:8.1-19.5%; P < 0.001). The pooled 2 years BF rate was 24% (95% CI: 19.1-30.2%, P < 0.001). The pooled 4 years BF was 35.6% (95% CI: 28.7-44.3%, P < 0.001). The pooled result of G ≥ 3 acute toxicity was 1.4% (95%CI: 0.7-3%, P < 0.001). One hundred and three G ≥ 3 late adverse events were reported, with a pooled result of G ≥ 3 late toxicity of 8.7% (95%CI: 5.8-13%, P < 0.001).

CONCLUSIONS

Re-I of local failures from PC showed promising OM and biochemical control rates with a safe toxicity profile.

Health-related quality of life after ultrafocal salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer: reporting the patient’s perspective

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We analyzed patient-reported quality of life in 100 patients who underwent ultrafocal salvage HDR-brachytherapy.

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Patient-reported bowel symptoms were neglible.

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Urinary complaints increased and sexual functioning declined over time.

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Lower impact is predicted for patients with favorable function at baseline and lower dose to the urethra.

Purpose

For patients with a localized prostate cancer recurrence after radiotherapy, focal salvage treatment offers a less toxic alternative to whole-gland treatments, with the potential of preserving health-related quality of life (HR-QoL). With a focus on the patient’s perspective of treatment, this study aims to describe HR-QoL after ultrafocal salvage high-dose-rate brachytherapy (HDR-BT), and to explore predictive factors affecting HR-QoL.

Material and methods

We included 100 patients treated with ultrafocal salvage HDR-BT. Prostate cancer-related HR-QoL was assessed by the EORTC QLQ-PR25 questionnaire. Domains were urinary symptoms, bowel symptoms and sexual activity/functioning. For each domain, a mixed effects model was made to estimate HR-QoL trends over time. For domains showing clinically relevant change (≥10 points difference), the mixed effects model was used to explore potential predictors (age, baseline HR-QoL score, T-stage, tumor location, CTV size, dose to organs at risk and history of ADT).

Results

Median follow-up was 20 months (IQR 13–30). Mean questionnaire response rate was 86% (range 72–100%). Median baseline scores were 12 (urinary), 0 (bowel) and 67/50 (sexual activity/functioning). Urinary symptoms and sexual functioning showed clinically relevant deterioration over time (maximum difference of 11 and 12 points, respectively). Worse baseline score and higher administered dose to the urethra (≥16 Gy) were predictive of increased urinary symptoms (p < 0.01 and p = 0.03). Better baseline score was predictive of better sexual functioning (p < 0.01).

Conclusion

Ultrafocal salvage HDR-BT has negligible impact on bowel symptoms but does affect urinary symptoms and sexual functioning. Lower impact is predicted for patients with favorable urinary and sexual function at baseline. Urethral dose constraints should be closely monitored.

Minimally invasive strategies for the treatment of prostate cancer recurrence after radiation therapy: a systematic review

INTRODUCTION

The aim of this review was to conduct a comprehensive analysis of the role of minimally invasive salvage modalities in radio-recurrent prostate cancer and the associated clinical outcomes and toxicity profiles.

EVIDENCE ACQUISITION

A systematic review of the current literature was conducted through the Medline and NCBI PubMed, Scopus databases in January 2020. All papers published after 2000, concerning studies conducted on humans for radio-recurrent prostate cancer were considered for the review.

EVIDENCE SYNTHESIS

Overall, 545 studies were identified. After duplicate exclusion, initial screening, and eligibility evaluation, a total of 80 studies were included in the qualitative analysis, corresponding to a cohort of 6681 patients. The median age at initial diagnosis ranged from 59 to 75.5. Pre-treatment PSA ranged from 6.2 to 27.4 ng/mL. All patients underwent primary radiotherapy for localized prostate cancer. Cryotherapy, Brachytherapy, EBRT, HIFU were the minimally invasive options mostly used as salvage therapy. They showed to be promising approaches for recurrent prostate cancer (PCa) control, with acceptable toxicities.

CONCLUSIONS

Minimally invasive therapeutic options offer promising results in terms of biochemical control in the local recurrence setting. Unfortunately, the absence of high quality and comparative studies makes it difficult to establish which method is the best in terms of oncological and safety outcomes.

Can brachytherapy be properly considered in the clinical practice? Trilogy project: The vision of the AIRO (Italian Association of Radiotherapy and Clinical Oncology) Interventional Radiotherapy study group

Purpose

Brachytherapy (BT, interventional radiotherapy - IRT) is a kind of radiation therapy, in which the radioactive source is placed nearby or even inside the cancer itself. Even though this kind of radiation therapy appears effective and valuable, BT has been facing a slow but progressive decline over the past decades in Europe, particularly in Italy. Aims of this study were to identify the practical and theoretical reasons why BT is facing a slow decline in Italy, and to define a vision of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) and a strategy about this emerged issues.

Material and methods

A programmatic path divided into three steps like a trilogy was launched by AIRO Interventional Radiotherapy study group. The study group performed an initial data collection to highlight both the clinical and the educational topics and problems through specific surveys. After having analyzed the results of the surveys and shared a vision about the emerged issues, a specific strategy was adopted.

Results

Four relevant domains were identified and for each ones, a strategy has been discussed and defined. This manuscript shows in detail the individual actions defined (accomplished or in progress).

Conclusions

The AIRO vision implies that specific strategic interventions must be carried out in the field of national guidelines, education, research, and communication with patients and colleagues of other specialties in an interdisciplinary setting.

Helical tomotherapy re-irradiation for patients affected by local radiorecurrent prostate cancer

Background

Salvage re-irradiation in patients affected by radiorecurrent prostate cancer might be a valid as well as challenging treatment option. The aim of this study was to evaluate feasibility and toxicity of salvage external beam radiotherapy (EBRT) re-treatment in patients affected by radiorecurrent prostate cancer within the prostate gland or the prostate bed.

Materials and Methods

15 patients underwent EBRT re-treatment using helical tomotherapy (HT), with daily Megavolt computed tomography image-guidance. We registered toxicity according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0. Biochemical relapse was defined as a PSA increase > 20% compared with the pre-EBRT re-treatment value. Survival curves were calculated using the Kaplan-Meier method.

Results

All patients received a total dose of 50 Gy (25 × 2 Gy), and 7 (46.6%) had concomitant androgen deprivation therapy (median duration of 12 months). With a median follow-up of 40.9 months, the 2-year and 4-year biochemical relapse-free survival were 55% and 35%, respectively. Acute and late genito-urinary (GU) toxicity ≥2 were recorded in 4 (26.6%) and 5 (33.3%) patients, respectively, and the 4-year late GU toxicity was 30%. Acute gastrointestinal toxicity ≥2 was recorded in 2 (13.3%) cases, whereas no patient experienced late toxicity.

Conclusions

Despite the inherent bias of a retrospective analysis, our long-term results showed a low toxicity profile with a relatively low rate of biochemical control for HT re-treatment in patients affected by local radiorecurrent prostate cancer. Prospective trials are needed to investigate the role of EBRT in this setting.

Salvage reirradiation for local prostate cancer recurrence after radiation therapy. For who? When? How?

PURPOSE

Literature review reporting results of salvage brachytherapy and stereotactic body radiotherapy for prostate recurrence only after radiotherapy for prostate cancer.

MATERIALS AND METHODS

A total of 38 studies (including at least 15 patients per study) were analysed: 19 using low-dose-rate brachytherapy, nine high-dose-rate brachytherapy and ten stereotactic body radiotherapy. Only five studies were prospective. The median numbers of patients were 30 for low-dose-rate brachytherapy, 34 for high-dose-rate brachytherapy, and 30 for stereotactic body radiotherapy. The median follow-up were 47months for low-dose-rate brachytherapy, 36months for high-dose-rate brachytherapy and 21months for stereotactic body radiotherapy.

RESULTS

Late genitourinary toxicity rates ranged, for grade 2: from 4 to 42% for low-dose-rate brachytherapy, from 7 to 54% for high-dose-rate brachytherapy and from 3 to 20% for stereotactic body radiotherapy, and for grade 3 or above: from 0 to 24% for low-dose-rate brachytherapy, from 0 to 13% for high-dose-rate brachytherapy and from 0 to 3% for grade 3 or above (except 12% in one study) for stereotactic body radiotherapy. Late gastrointestinal toxicity rates ranged, for grade 2: from 0 to 6% for low-dose-rate brachytherapy, from 0 to 14% for high-dose-rate brachytherapy and from 0 to 11% for stereotactic body radiotherapy, and for grade 3 or above: from 0 to 6% for low-dose-rate brachytherapy, and from 0 to 1% for high-dose-rate brachytherapy and stereotactic body radiotherapy. The 5-year biochemical disease-free survival rates ranged from 20 to 77% for low-dose-rate brachytherapy and from 51 to 68% for high-dose-rate brachytherapy. The 2- and 3-year disease-free survival rates ranged from 40 to 82% for stereotactic body radiotherapy. Prognostic factors of biochemical recurrence have been identified.

CONCLUSION

Despite a lack of prospective data, salvage reirradiation for prostate cancer recurrence can be proposed to highly selected patients and tumours. Prospective comparative studies are needed.

Current state of interventional radiotherapy (brachytherapy) education in Italy: results of the INTERACTS survey

PURPOSE

Increased complexity of interventional radiotherapy (brachytherapy - BT) treatment planning and quality control procedures has led to the need of a specific training. However, the details of the features of BT learning objectives and their distribution in the training paths of the Italian Radiation Oncology Schools are not known. This paper aims to provide the actual 'state-of-the-art' of BT education in Italy and to stimulate the debate on this issue.

MATERIAL AND METHODS

All the Italian radiation oncology schools' directors (SD) were involved in a web survey, which included questions on the teaching of BT, considering also the 2011 ESTRO core curriculum criteria. The survey preliminary results were discussed at the 8^th Rome INTER-MEETING (INTERventional Radiotherapy Multidisciplinary Meeting), June 24^th, 2017. The present paper describes the final results of the survey and possible future teaching strategies resulting from the discussion.

RESULTS

A total of 23 SDs answered the survey. The results evidenced a wide heterogeneity in the learning activities available to trainees in BT across the country. While theoretical knowledge is adequately and homogeneously transmitted to trainees, the types of practice to which they are exposed varies significantly among different schools.

CONCLUSIONS

This survey proves the need for an improvement of practical BT education in Italy and the advisability of a national BT education programme networking schools of different Universities. Beside the organization of national/international courses for BT practical teaching, Universities may also establish post-specialization courses ('second level' Masters) to allow professionals (already certified in radiation oncology) to acquire more advanced BT knowledge.

Nonsurgical Salvage Local Therapies for Radiorecurrent Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Different nonsurgical therapeutic strategies can be adopted for intraprostatic relapse of prostate cancer after primary radiotherapy, including re-irradiation (with brachytherapy [BT] or external beam radiotherapy [EBRT]), high-intensity focused ultrasound (HIFU), and cryotherapy. The main issues to consider when choosing nonsurgical salvage local therapies are local tumor control and significant genitourinary toxicity.

OBJECTIVE

To conduct a systematic review and meta-analysis of the role of nonsurgical salvage modalities in patients with radiorecurrent prostate cancer and associated clinical outcomes and toxicity profiles.

EVIDENCE ACQUISITION

We performed a critical review of the Medline, Scopus, and ClinicalKey databases from January 1, 2000 through February 1, 2018 according to the Preferred Reporting Items and Meta-Analyses statement. To assess the overall quality of the literature reviewed, we used a modified Delphi tool for case-series studies.

EVIDENCE SYNTHESIS

A total of 64 case-series studies were included, corresponding to a cohort of 5585 patients. The modified Delphi checklist evidenced high methodological quality overall (mean quality score of 80.6%). Biochemical control rates were lowest for patients treated with HIFU (58%, 95% confidence interval [CI] 47-68%) and highest for patients treated with BT (69%, 95% CI 62-76%) and EBRT (69%, 95% CI 53-83%). The lowest prevalence of incontinence was for patients treated with BT (3%, 95% CI 0-6%; I²=63.4%) and the highest was among patients treated with HIFU (28%, 95% CI 19-38%; I²=89.7%).

CONCLUSIONS

Nonsurgical therapeutic options, especially BT, showed good outcomes in terms of biochemical control and tolerability in the local recurrence setting.

PATIENT SUMMARY

The current analysis demonstrated that nonsurgical salvage local therapies offer a chance of a curative local approach in radiorecurrent prostate cancer. However, high-quality data from prospective trials are needed to validate long-term outcomes from nonsurgical strategies for the treatment of intraprostatic recurrence after previous radiotherapy.

Salvage CyberKnife-Based Reirradiation of Patients With Recurrent Prostate Cancer: The Single-Center Experience

The aim of this study was to evaluate CyberKnife-based radioablation as a salvage treatment for prostate cancer postirradiation relapses based on a group of patients disqualified from available conventional methods of salvage treatment. Thirty-eight patients were treated with a fraction dose varying from 5.5 to 10 Gy (median 7.35) to a total dose of 18 to 36.25 Gy (median 36.25). In all, 55.3% of patients had androgen deprivation therapy during this time. Nine patients had oligometastases in the salvage time. The follow-up varied from 1.6 to 46.4 months (mean 19.7, median 14.4). In all, 92.6% to 97.4% of patients had no gastrointestinal acute adverse effects; no effects higher than G1 were noted. There were particular (up to 4.8%) G2 late gastrointestinal effects. The percentage without genitourinary acute effects varied from 59.1% to 78.9%; 3.7% had G3 toxicity. G3 late genitourinary toxicity appeared 3 times, the maximal percentage being 12.5% (24 months after salvage treatment). The nadir of prostate-specific antigen median was 0.24 ng/mL (9 months after treatment). Twelve (31.6%) patients failed in the timeline of 6 to 42 months after salvage treatment (mean 18.7, median 16.5)—5 due to dissemination. In 2 cases, progression in existing metastases was identified. Five (13.2%) patients had biochemical failure without additional metastases (local relapses); hence, local control was 86.8%. The failure risk is strongly influenced by initial disease stage and presalvage prostate-specific antigen concentration. The obtained results permit us to conclude that such a treatment could be an effective and safe option for prostate cancer postirradiation relapse salvage treatment.