Salvage cryotherapy for radiation-recurrent prostate cancer: outcomes and complications

The Safety and Efficacy of Salvage Stereotactic Radiation Therapy in Patients with Intraprostatic Tumor Recurrence After Previous External Radiation Therapy: Phase 1 Results from the GETUG-AFU 31 Study

BACKGROUND

There is no consensus on the best local salvage treatment for prostate cancer recurrence after primary external beam radiotherapy. Prospective data on stereotactic body radiation therapy (SBRT) are very scarce.

OBJECTIVE

To determine the optimal dose regimen for salvage SBRT.

DESIGN, SETTING, AND PARTICIPANTS

The present report concerns the phase 1 part of the GETUG-AFU 31 multicenter open-label study. The main inclusion criteria were histologically proven biochemical recurrence, clinical stage T1-T2 upon relapse, multiparametric magnetic resonance imaging data, prostate-specific antigen (PSA) level ≤10 ng/ml prior to salvage SBRT, PSA doubling time >10 mo, and an International Prostate Symptom Score of ≤12.

INTERVENTION

Five or six fractions of 6 Gy were delivered using focal SBRT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Dose-limiting toxicity (DLT) was defined as grade ≥3 gastrointestinal or genitourinary tract toxicity, or any grade 4 toxicity (according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.03) occurring in the first 18 wk following treatment initiation. A time-to-event continual reassessment method was used to select the dose regimen.

RESULTS AND LIMITATIONS

Twenty-one patients were treated (median [interquartile range] age: 76.8 yr [72.2-80.8]), including 12 at 6 × 6 dose level. No DLT was observed. The acute grade 2 genitourinary tract toxicity rate was 19%. With a median follow-up of 12.3 mo, the estimated cumulative incidence of late grade 2 genitourinary toxicity was 41.2% (95% confidence interval: 18.1-63.1%). No grade >2 genitourinary toxicity and no grade ≥2 gastrointestinal toxicity were reported. All treated patients were alive and relapse free at the last follow-up.

CONCLUSIONS

A 6 × 6 Gy dose regimen was selected for our phase 2 study of salvage SBRT. With a short follow-up period, the level of toxicity appears to be acceptable.

PATIENT SUMMARY

There is no consensus on the best local treatment for patients with local relapse after radiotherapy for prostate cancer. Prospective data are very scarce. Our early phase trial allowed us to recommend six fractions of 6 Gy using high-precision radiotherapy for further studies.

Image-guided percutaneous cryo-ablation of peri-urethral unresectable recurrent pelvic malignancy: A case report and brief review

Recurrent or metastatic peri-urethral pelvic malignancies are a difficult-to-treat entity. Re-resection is recommended when possible but is frequently unfavorable due to scar tissue, fibrosis, and obliteration of tissue planes following previous interventions such as surgical resection and/or radiation therapy. Curative options for patients that have unresectable cancer are limited. Cryo-ablation has been extensively studied in the treatment of unresectable renal, liver and lung malignancies and has the potential to provide definitive treatment for recurrent pelvic malignancy. There is a paucity of reports of salvage cryo-ablation in patients with recurrent pelvic malignancies, as most of these tumors are located close to critical structures that could be irreversibly injured by thermal ablation and are hence treated with some form of radiation therapy. But, for patients who fail surgical and radiation treatments, options are limited. Here, we describe two cases of regional tumor recurrence in the pelvis treated with percutaneous cryoablation using protective techniques to avoid thermal injury to adjacent structures. In each case, cryo-ablation was performed successfully despite extensive previous surgical and radiation interventions. Salvage cryo-ablation resulted in a positive clinical and imaging response with an improvement in quality of life and absence of recurrence on follow-up imaging which continues to persist at the writing of this manuscript about 8 and 12-months following treatment.

Management of Isolated Local Failures Following Stereotactic Body Radiation Therapy for Low to Intermediate Risk Prostate Cancer

Background: Stereotactic body radiation therapy (SBRT) is a safe and effective treatment option for patients with low to intermediate risk prostate cancer (1). SBRT results in very low PSA nadirs secondary to the delivery of high biologically effective doses. Studies reporting on the diagnosis, confirmation, and management of salvageable isolated local failures (ILF) are limited. This study aims to determine the incidence and management approach of ILF after SBRT in a large single institution cohort. Method: All patients with low or intermediate risk localized prostate cancer treated with SBRT at Georgetown University Hospital were eligible for this study. Treatment was delivered using robotic SBRT with doses of 35-36.25 Gy in five fractions. ILF were diagnosed using multiparametric MRI and/or biopsy prompted by rising PSA levels after achieving long-term nadir. Patient's characteristics were extracted from a prospective institutional quality of life trial (IRB 2009-510). Type of salvage therapy and post-salvage PSA were determined on subsequent follow-up and chart review. Results: Between December 2008 to August 2018, 998 men with low to intermediate risk prostate cancer were eligible for inclusion in this analysis. Twenty-four patients (low risk, n = 5; intermediate risk, n = 19) were found to have ILF within the prostate on either MRI (n = 19) and/or biopsy (n = 20). Median pre-treatment PSA was 7.55 ng/ml. Median time to diagnosis of ILF was 72 months (24-110 months) with median PSA at the time of ILF of 2.8 ng/ml (0.7-33 ng/ml). Median PSA doubling time was 17 months (5-47 months). Thirteen patients with biopsy proven ILF proceeded with salvage therapy (cryotherapy n = 12, HIFU n = 1). Of 12 patients who underwent cryotherapy, 7 had a post-treatment PSA of <0.1 ng/ml. One patient experienced a urethral-cutaneous fistula (grade 3 toxicity). Conclusion: The incidence of isolated local recurrence is rare in our cohort. Diagnosis and management of isolated local failures post-SBRT continues to evolve. Our report highlights the importance of early utilization of MRI and confirmatory biopsy at relatively low PSA levels and long PSA doubling time (1). Additionally, undetectable PSA levels after salvage therapy supports the role of early treatment in ILF (1). Further research is needed to determine appropriate patient selection and salvage modality in this population.

Oncological outcomes of salvage cryotherapy after primary radiation therapy vs. primary cryotherapy: 10-year experience at a large Canadian referral center

INTRODUCTION

Salvage cryotherapy is a guideline-recommended treatment of localized prostate cancer recurrence after radiation therapy. There is little published evidence analyzing the outcomes of salvage cryotherapy for recurrent prostate cancer following different primary therapy energy modalities.

METHODS

We performed a retrospective analysis of patients who received whole gland salvage cryotherapy from 2007-2017 at a large tertiary referral center after either primary radiation therapy (RT) or primary whole gland cryotherapy. Primary outcome was biochemical failure, defined as per the Phoenix criteria (prostate-specific antigen [PSA] nadir + 2.0 ng/ml). Secondary outcomes included time to biochemical failure and development of metastatic disease.

RESULTS

Fifty-eight of 391 patients who received cryotherapy were identified as having received salvage cryotherapy (after RT, n=37; after primary cryotherapy, n=21). Biochemical recurrence occurred in 21 (57%) patients with previous RT and in 17 (81%) patients with previous cryotherapy (p=0.001). Median time to biochemical recurrence was 18 months for patients with previous RT and 13 months for patients with previous cryotherapy (p=0.002). The biochemical-free survival rate for primary radiation therapy patients was 71% at two years compared to 23% at two years for patients who underwent primary cryotherapy (p<0.01). There was no difference in the development of metastatic disease between groups (19% vs. 18%, cryo vs. radiation, p=0.34).

CONCLUSIONS

These results suggest that salvage cryotherapy may offer more durable oncological control to patients after radiation compared to primary cryotherapy, with a lower rate and longer duration before biochemical recurrence.

GETUG-AFU 31: a phase I/II multicentre study evaluating the safety and efficacy of salvage stereotactic radiation in patients with intraprostatic tumour recurrence after external radiation therapy-study protocol

INTRODUCTION

Prostate cancer is the third most important cancer in terms of mortality in men. No standard local treatment exists for patients with an intraprostatic recurrence after radiotherapy. Stereotatic body radiotherapy (SBRT) could be a curative treatment for local recurrence. The phase I/II primary objective is the selection of the recommended dose for salvage-SBRT and to estimate the efficacy.

METHODS AND ANALYSIS

We plan to perform a multicentre prospective phase I/II study including at least 47 patients. Eligible patients are patients with biochemical recurrence occurring at least 2 years after external radiotherapy for prostatic adenocarcinoma by the Phoenix definition (prostate-specific antigen (PSA) nadir +2 ng/mL) and histologically proven intraprostatic recurrence only (stage T1-T2 on relapse, PSA level ≤10 ng/mL, PSA doubling time >10 months, absence of pelvic or metastatic recurrence proven by choline or PSMA positron emission tomography scan, and pelvic and prostatic assessment by multiparametric MRI). The phase I primary objective is the selection of the recommended dose for salvage-SBRT (5×6, 6×6 or 5×5 Gy) based on dose-limiting toxicity (DLT). The dose of salvage-SBRT will be selected using a time-to-event continual reassessment method based on DLT defined as grade ≥3 gastrointestinal or urinary toxicity or any other grade 4 adverse event. The phase II primary outcome is to estimate the efficacy of the salvage-SBRT in terms of biochemical relapse-free survival rate (Phoenix definition: increase in serum total PSA ≥2 ng/mL above the nadir). Phase II secondary outcomes are acute and late toxicities, quality of life, clinical progression-free survival defined as the time interval between the date of registration and the date of clinical progression or death irrespective of the cause.

ETHICS AND DISSEMINATION

The study has received ethical approval from the Ethics committee 'Ile-de-France III'. Academic dissemination will occur through publication and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03438552.

Salvage cryoablation for local recurrence of prostatic cancer after curative therapy

PURPOSE

The purpose of this study was to determine the efficacy of salvage cryotherapy for intra-prostatic and local extraprostatic recurrences after curative treatment of prostate adenocarcinoma.

MATERIAL AND METHOD

Twenty-eight men (mean age, 69±6 [SD] years; range: 51-82 years) treated with cryoablation for prostatic (N=21) or extraprostatic (N=7) recurrent prostate cancer after radiotherapy with or without associated prostatectomy were included. Technical success, complication and recurrences were reported. Biological recurrence was defined as an elevation ≥2ng/mL of prostate specific antigen (PSA) serum level after the treatment.

RESULTS

The mean follow-up was 18 months. Among the 21 patients with intraprostatic recurrence, 14 had successful cryotherapy with a mean decrease in serum prostate-specific antigen (PSA) levels of -5.7±2.6 (SD) ng/mL (range: -2.1 to -16.9ng/mL). Four patients (19%) had early progression and three patients (14%) had delayed biological recurrence (mean time: 15 months). Among the 7 patients with extraprostatic recurrence, 2/7 (291%) had successful cryotherapy with a decrease in PSA serum level of -2.7±1.6 (SD) ng/mL (range: -0.5--5.5ng/mL) and 4/7 (57%) had early biological recurrence after cryotherapy that required androgen deprivation therapy, whereas 1/7 (4%) was lost to follow-up. No major complications were observed for both intra- and extraprostatic recurrence.

CONCLUSION

Salvage cryoablation of locally recurrent prostate cancer after curative treatment is feasible and safe when the half prostate is treated. It could delay initiation of androgen deprivation therapy in these patients.

Percutaneous MR-guided whole-gland prostate cancer cryoablation: safety considerations and oncologic results in 30 consecutive patients

OBJECTIVE

To assess the safety and oncological efficacy of percutaneous MR-guided whole-gland prostate cancer (PCa) cryoablation (CA).

METHODS AND MATERIALS

Between July 2009 and January 2018, 30 patients (mean age 72.9 ± 5.13 years) with histologically proven, organ-confined (≤ T2cN0M0), predominantly low/intermediate-risk PCa (median Gleason score 7; mean prostate specific antigen 6.05 ± 3.74 ng ml^-1 ) underwent MR-guided whole-gland CA. Patients were selected on the basis of prior pelvic radiotherapy (n = 16; 12 for previous PCa), or contra indication/refusal of surgery or radiotherapy. Complications, local progression-free survival (LPFS) and overall survival (OS) were retrospectively investigated.

RESULTS

Eighteen [60%] patients reported procedure-related complications: 5/18 [28%] needed surgical/interventional treatments and 13 [72%] conservative or pharmacological treatment. Eleven [73%] complications were noted in the first 15 patients and 7 [47%] in the last 15 patients (p = 0.26). Mean nadir prostate specific antigen was 0.24 ± 1.5 ng ml^-1 (mean follow-up 3.8 years; range: 2 - 2915 days). Seven [23%] patients developed histologically proven local progression (mean time to recurrence 775 days, range: 172 - 2014). Mean clinical follow-up was 3.8 years (range 1-2915 days). LPFS was 92.0, 75.7 and 69.4 % at 1-, 3- and 5 year follow-up, respectively. For patients in salvage treatment, LPFS was 100%, 75%, and 75% at 1-, 3- and 5 year follow-up. OS was 100%, 94.4 and 88.5 % at 1-, 3- and 5 year follow-up respectively, with no patients dying from PCa.

CONCLUSION

Whole-gland PCa CA offers good oncological efficacy, particularly in post-radiotherapy cases. Although the complication rate is significant, the majority is minor and is managed with conservative or pharmacologic management.

ADVANCES IN KNOWLEDGE

MRI-guided whole-gland prostate cancer cryoablation offers good oncological efficacy, particularly in post-radiotherapy cases with a contained complication rate.

Percutaneous MR-guided focal cryoablation for recurrent prostate cancer following radiation therapy: retrospective analysis of iceball margins and outcomes

OBJECTIVES

To evaluate iceball margins after magnetic resonance (MR)-guided focal salvage prostate cryoablation and determine the correlation with local outcome.

METHODS

A retrospective review was performed on 47 patients that underwent percutaneous MR-guided focal cryoablation for biopsy-proven locally recurrent prostate cancer after primary radiotherapy. Preprocedural diagnostic and intraprocedural MR images were analysed to derive three-directional iceball margins. Local tumour progression after cryoablation was defined as evident tumour recurrence on follow-up MRI, positive MR-guided biopsy or biochemical failure without radiological evidence of metastatic disease.

RESULTS

Mean iceball margins were 8.9 mm (range -7.1 to 16.2), 10.1 mm (range 1.1-20.3) and 12.5 mm (range -1.5 to 22.2) in anteroposterior, left-right and craniocaudal direction respectively. Iceball margins were significantly smaller for tumours that were larger (P = .008) or located in the posterior gland (P = .047). Significantly improved local progression-free survival at 1 year post focal cryoablation was seen between patients with iceball margin >10 mm (100%), 5-10 mm (84%) and <5 mm (15%) (P < .001).

CONCLUSIONS

Iceball margins appear to correlate with local outcome following MR-guided focal salvage prostate cryoablation. Our initial data suggest that freezing should be applied at minimum 5 mm beyond the border of an MR-visible recurrent prostate tumour for successful ablation, with a wider margin appearing desirable.

KEY POINTS

• Shortest iceball margin most often occurred in anteroposterior direction • Margins were smaller in tumours that were larger or posteriorly located • Minimum iceball margin was a predictor of early local tumour progression • A minimum 5-mm margin seems required for effective cryoablation of recurrent PCa.

Single fraction multimodal image guided focal salvage high-dose-rate brachytherapy for recurrent prostate cancer

PURPOSE

We present a novel method for treatment of locally recurrent prostate cancer (PCa) following radiation therapy: focal, multimodal image guided high-dose-rate (HDR) brachytherapy.

MATERIAL AND METHODS

We treated two patients with recurrent PCa after primary (#1) or adjuvant (#2) external beam radiation therapy. Multiparametric magnetic resonance imaging (mpMRI), choline, positron emission tomography combined with computed tomography (PET/CT), or prostate-specific membrane antigen (PSMA)-PET combined with CT identified a single intraprostatic lesion. Positron emission tomography or magnetic resonance imaging - transrectal ultrasound (MRI-TRUS) fusion guided transperineal biopsy confirmed PCa within each target lesion. We defined a PET and mpMRI based gross tumor volume (GTV). A 5 mm isotropic margin was applied additionally to each lesion to generate a planning target volume (PTV), which accounts for technical fusion inaccuracies. A D90 of 18 Gy was intended in one fraction to each PTV using ultrasound guided HDR brachytherapy.

RESULTS

Six month follow-up showed adequate prostate specific antygen (PSA) decline in both patients (ΔPSA 83% in patient 1 and ΔPSA 59.3% in patient 2). Follow-up 3-tesla MRI revealed regressive disease in both patients and PSMA-PET/CT showed no evidence of active disease in patient #1. No acute or late toxicities occurred.

CONCLUSIONS

Single fraction, focal, multimodal image guided salvage HDR brachytherapy for recurrent prostate cancer is a feasible therapy for selected patients with single lesions. This approach has to be evaluated in larger clinical trials.

Methodology of patient care for elevated PSA after prostate cancer treatment: A primary care perspective

Prostate cancer (PCa) remains one of the most common cancers in men. Each year there are 230,000 new cases and it causes nearly 30,000 deaths. Elevations in prostate-specific antigen (PSA) after treatment with radiation or surgery can indicate the presence of PCa recurrence. About 15-18% of men treated for PCa will have an elevation of their PSA, which is a source of great concern and will lead to a management discussion with the patient. Approximately 25-33% of men with PCa will experience a recurrence of their cancer after surgery or radiation. This article will discuss the different options for men with a rising PSA after definitive therapy or an attempt at curative treatment for PCa. The purpose of this article is to help the primary care doctor, internist and geriatrician to become knowledgeable about the treatment options of recurrent PCa so that they can participate in the discussion with the patient and help the patient reach a decision regarding treatment and management of the elevated PSA levels, which signal recurrent disease.

Feasibility study of a randomised controlled trial to compare (deferred) androgen deprivation therapy and cryotherapy in men with localised radiation-recurrent prostate cancer

BACKGROUND

Salvage therapeutic options for biochemical failure after primary radiation-based therapy include radical prostatectomy, cryoablation, high-intensity focused ultrasound (HIFU), brachytherapy (for post-EBRT patients) and androgen deprivation therapy (ADT). ADT and salvage prostate cryoablation (SPC) are two commonly considered treatment options for RRPC. However, there is an urgent need for high-quality clinical studies to support evidence-based decisions on treatment choice. Our study aims to determine the feasibility of randomising men with RRPC for treatment with ADT and SPC.

METHODS

The randomised controlled trial (CROP) was developed, which incorporated protocols to assess parameters relating to cryotherapy procedures and provide training workshops for optimising patient recruitment. Analysis of data from the recruitment phase and patient questionnaires was performed.

RESULTS

Over a period of 18 months, 39 patients were screened for eligibility. Overall 28 patients were offered entry into the trial, but only 7 agreed to randomisation. The majority reason for declining entry into the trial was an unwillingness to be randomised into the study. 'Having the chance of getting cryotherapy' was the major reason for accepting the trial. Despite difficulty in retrieving cryotherapy temperature parameters from prior cases, 9 of 11 cryotherapy centres progressed through the Cryotherapists Qualification Process (CQP) and were approved for recruiting into the CROP study.

CONCLUSIONS

Conveying equipoise between the two study arms for a salvage therapy was challenging. The use of delayed androgen therapy may have been seen as an inferior option. Future cohort studies into available salvage options (including prostate cryotherapy) for RRPC may be more acceptable to patients than randomisation within an RCT.

Complications and outcomes of salvage robot-assisted radical prostatectomy: a single-institution experience

OBJECTIVE

To determine the peri-operative outcomes of men undergoing salvage robot-assisted prostatectomy (RARP) and to examine the complications, functional consequences and need for additional treatments after salvage RARP.

PATIENTS AND METHODS

At total of 51 consecutive patients underwent salvage RARP after previous failed local therapy. Biochemical recurrence (BCR) was defined as two postoperative PSA measurements ≥0.2 ng/mL. Complications at any time postoperatively were recorded prospectively using a modified Clavien system. The Kaplan-Meier method was used for survival estimation, and regression models were used to identify the predictors of BCR or progression-free survival (PFS) and complications.

RESULTS

The median age at salvage RARP was 68 years and a median of 68 months had elapsed from the time of primary treatment. The median follow-up was 36 months. The median operation duration was 179 min with a median estimated blood loss of 175 mL. In all, 50% of patients had pathological stage 3 disease and positive surgical margins were found in 31% of patients. The estimated 3-year BCR-free or PFS was 57%. The overall complication rate was 47%, with a 35% major complication rate (Grade III-V). Potency was maintained in 23% of preoperatively potent patients and 45% of all patients regained urinary control. No clinical variables were predictive of major complications, but all patients with postoperative bladder neck contracture were incontinent. A higher PSA level and extracapsular extension were significantly associated with BCR or progression (P < 0.01).

CONCLUSIONS

Salvage RARP provides oncological control with potential avoidance of systemic non-curative therapy. Complication, incontinence and erectile dysfunction rates are significant but frequently correctable. This reinforces the need for proper patient counselling and selection.

Population-based comparative effectiveness of salvage radical prostatectomy vs cryotherapy

OBJECTIVE

To characterize population-based practice patterns, disease-specific and overall mortality, and cost associated with salvage cryotherapy (SCT) vs salvage radical prostatectomy (SRP).

METHODS

We retrospectively identified 440 men who failed primary radiation therapy and subsequently underwent SCT (n = 341, 77.5%) or SRP (n = 99, 22.5%) between 1992 and 2009 from Surveillance, Epidemiology, and End Results-Medicare linked data. Propensity score analyses were used to compare overall and prostate cancer-specific mortality and associated Medicare expenditures for SRP vs SCT.

RESULTS

Men undergoing SCT were more likely to be white (P <.001), less likely to be high school graduates (P = .008), and experienced shorter median time from diagnosis to salvage therapy (44.1 vs 60.1, P <.001) and from primary radiotherapy to salvage therapy (38.7 vs 55.8 months, P <.001). In adjusted analyses, overall mortality was higher (21.6 vs 6.1 deaths/100 person years, P <.001) for SRP vs SCT. There was a trend for higher prostate cancer-specific death rates with SRP vs SCT (6.5 vs 1.4 deaths/100 person years, P = .061). Medicare expenditures for SRP vs SCT were more than 2-fold higher ($19,543 vs $8,088, P <.001).

CONCLUSION

SRP vs SCT is associated with higher overall mortality and greater health care expenditures. However, longer follow-up is needed to assess long-term functional outcomes and cancer control.

The effects of metallic implants on electroporation therapies: feasibility of irreversible electroporation for brachytherapy salvage

PURPOSE

Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments.

MATERIALS AND METHODS

This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions.

RESULTS

There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins.

CONCLUSION

This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.

Advances in imaging and in non-surgical salvage treatments after radiorecurrence in prostate cancer: what does the oncologist, radiotherapist and radiologist need to know?

OBJECTIVES

In this article the state of art the of prostate cancer (Pca) imaging and non-surgical salvage treatments (STs) is surveyed in order to explore the impact of imaging findings on the identification of radiorecurrent Pca after external beam radiotherapy (EBRT).

METHODS

A computerised search was performed to identify all relevant studies in Medline up to 2012. Additional articles were extracted based on recommendations from an expert panel of authors.

RESULTS

Definitive EBRT for Pca is increasingly used as treatment. After radiorecurrent Pca, non-surgical STs are emerging and shifting from investigational status to more established therapeutic options. Therefore, several scientific societies have published guidelines including clinical and imaging recommendations, even if the timing, efficacy and long-term toxicity of these STs have to be established. In some measure, accurately delineating the location and the extent of cancer is critical in selecting target lesions and in identifying patients who are candidates for STs. However, there is increasing awareness that anatomical approaches based on measurements of tumour size have substantial limitations, especially for tumours of unknown activity that persist or recur following irradiation

CONCLUSIONS

To date, the main focus for innovations in imaging is the combination of excellence in anatomical resolution with specific biological correlates that depict metabolic processes and hallmarks at the tumour level. The emergence of new molecular markers could favour the development of methods that directly determine their presence, thereby improving tumour detection.

KEY POINTS

Imaging may influence therapeutic decisions during non-surgical STs. MRI findings correlate with parametric maps derived from multiple functional techniques. Non-surgical salvage treatments allow local tumour control in patients with radiorecurrent PCa.