Role of imaging and biopsy to assess local recurrence after definitive treatment for prostate carcinoma (surgery, radiotherapy, cryotherapy, HIFU)

Evaluation of Recurrent Disease after Radiation Therapy for Patients Considering Local Salvage Therapy: Past vs. Contemporary Management

Recurrent prostate cancer after primary treatment with radiation therapy is a common problem. Patients with localized recurrence may benefit from salvage therapy, but careful patient selection is crucial because not all patients will benefit from local salvage therapy, and salvage therapy has increased morbidity compared to primary treatments for prostate cancer. This review aims to provide an overview of the evaluation of patients with recurrent disease after radiation therapy and how it is continuing to evolve with increasing data on outcomes, as well as improving technologies and techniques. Our enhanced understanding of treatment outcomes and risk stratification has influenced the identification of patients who may benefit from local salvage treatment. Advances in imaging and biopsy techniques have enhanced the accuracy of locating the recurrence, which affects treatment decisions. Additionally, the growing interest in image-targeted ablative therapies that have less morbidity and complications than whole-gland therapies for suitable patients influences the evaluation process for those considering focal salvage therapy. Although significant changes have been made in the diagnostic evaluation of patients with recurrent disease after radiation therapy, it remains unclear whether these changes will ultimately improve patient outcomes.

Outcomes of salvage robot-assisted radical prostatectomy in patients who had primary focal versus whole-gland ablation: a multicentric study

In the present study, we present comparative outcomes of radical prostatectomy after whole-gland therapy (wg-SRARP) and focal gland therapy (f-SRARP). The study assessed 339 patients who underwent salvage robot-assisted radical prostatectomy (SRARP); 145 patients who had primary focal therapy and 194 patients who had primary whole-gland treatment. SRARP was performed in all cases using a standardized technique developed at respective institutes with the da Vinci Xi Surgical System. Our primary endpoint was the comparison of the functional and oncological outcomes between the groups. Cox proportional hazard was used to study the functional and oncological outcomes. The median total operative time for f-SRARP was 18 min higher than wg-RARP (p < 0.001). Higher rates of nerve-sparing were performed in f-SRARP (focal vs whole gland; bilateral-15.2% vs 9.3%; unilateral 49% vs 28.4%; p < 0.001). wg-SRARP had higher rates of ISUP 5 (26.3% vs 19.3%; p < 0.001) and deferred ISUP score due to altered pathology (14.8% vs 0.7; p < 0.001), while f-SRARP had higher rates of ISUP 4 (11.7% vs 10.7%; p < 0.001) and ≥ pT3a (64.8% vs 51.6%; p < 0.001). Positive margins were significantly higher with f-SRARP (26.2% vs 10.3%; p < 0.001). Functional outcomes were poor in both the groups. However, postoperative continence was higher and faster in patients who had f-SRARP compared to wg-SRARP (69% vs. 54.6%; p = 0.013). We could not identify statistically significant difference in postoperative potency recovery and biochemical recurrence. We present the largest multi-institutional analyses of f-SRARP and wg-SRARP. SRARP is challenging wherein patients have adverse pathological features and increased surgical complexity irrespective of the primary treatment. Focal therapy group had higher rates of nerve-sparing, however, with increased positive surgical margins. Both groups had poor functional outcomes regardless of nerve-sparing degree, indicating significant ipsilateral and contralateral damage to tissues surrounding the prostate during primary treatment. We believe that this analysis is crucial for counseling patients regarding expected outcomes before performing a salvage treatment following ablative therapy failure.

Management of Biochemical Recurrence of Prostate Cancer After Curative Treatment: A Focus on Older Patients

Following a treatment with curative intent, a biochemical recurrence may be diagnosed, often many years after the primary treatment. The consequences of this relapse on survival are very heterogeneous. The expected specific survival at relapse is above 50% at 10 years. Therefore, its management needs to be balanced with the individual life expectancy. The relapse needs to be categorized as either a low- or high-risk category. The latter has to be considered for salvage therapy, provided the individual life expectancy is long enough. It is evaluated through an initial geriatric assessment, starting with the G8 score as well as the mini-Cog. A comprehensive geriatric assessment might be needed based on the G8 score. Patients will then be categorized as either fit, vulnerable, or frail. If a local salvage therapy is considered, the relapse localization might be of interest in some situations. Available salvage therapies in senior adults have nothing special compared to salvage of younger men, except for aggressive local therapy, which might be less well tolerated. The key objective in managing a biochemical recurrence in senior adults is to find the right balance between under- and over-treatment in a shared decision process. In many frail and vulnerable men, a clinically oriented watchful waiting should be preferred, while fit men with an aggressive relapse and a significant life expectancy need an active therapy.

Value of Targeted Biopsies and Combined PSMA PET/CT and mp-MRI Imaging in Locally Recurrent Prostate Cancer after Primary Radiotherapy

Simple Summary

After primary radiotherapy for prostate cancer, patients may develop an isolated local recurrence. The diagnostic workup of these recurrences guides decision making for potential focal salvage treatments. The aim of this study was to determine the positive predictive value (PPV) of combined multiparametric (mp) MRI and prostate specific membrane antigen (PSMA) PET/CT imaging in this setting, with histological conformation using MR-guided targeted biopsies. In 41 patients counseled for focal salvage high dose rate (HDR) brachytherapy, a PPV of 97.6% was found for combined mp-MRI and PSMA PET/CT. Therefore, biopsies can safely be omitted in these patients.

Abstract

Radiorecurrent prostate cancer is conventionally confirmed using systematic and/or targeted biopsies. The availability of multiparametric (mp) MRI and prostate specific membrane antigen (PSMA) PET/CT has increased diagnostic accuracy. The objective was to determine the positive predictive value (PPV) of combined mp-MRI and PSMA PET/CT and whether pathology verification with MR-targeted biopsies remains necessary for patients with radiorecurrent prostate cancer. Patients with locally recurrent prostate cancer who were referred for 19 Gy single-dose MRI-guided focal salvage high dose rate (HDR) brachytherapy between 2015 and 2018 were included in the current analysis. Patients were selected if they underwent pre-biopsy mp-MRI and PSMA PET/CT. Based on these images, lesions suspect for isolated tumor recurrence were transperineally biopsied using transrectal ultrasound fused with MRI. A total of 41 patients were identified from the database who underwent cognitive targeted (n = 7) or MRI/PSMA-transrectal ultrasound (TRUS) fused targeted (n = 34) biopsies. A total of 40 (97.6%) patients had positive biopsies for recurrent cancer. Five patients initially had negative biopsies (all MRI/PSMA-TRUS fusion targeted), four of whom recurrence was confirmed after a re-biopsy. One (2.4%) patient refused re-biopsy, leading to a positive predictive value (PPV) for combined imaging of 97.6%. Biopsies can therefore safely be withheld when the results of the combined mp-MRI and PSMA PET/CT are conclusive, avoiding an unnecessary invasive and burdensome procedure.

High Intensity Focused Ultrasound Ablation for Prostate Cancer: Whole Versus Partial Gland Ablation

BACKGROUND

We compared the clinical outcomes between whole-gland ablation (WGA) and partial gland ablation (PGA) using the high-intensity focused ultrasound (HIFU) technique for localized prostate cancer (PCa).

METHODS

We retrospectively investigated 206 patients who underwent WGA or PGA for localized PCa. Follow-up prostatic biopsy was performed 1 year postoperatively. We performed intergroup comparison of the postoperative functional and oncological outcomes and complication rates.

RESULTS

In this study, 152 and 54 patients underwent PGA and WGA, respectively. The total operation time was significantly longer in the WGA than in the PGA group (107.5 minutes vs. 95.0 minutes, P = .004). Of the 86 patients who underwent postoperative prostate biopsy, no residual cancer was detected in 70.4% of the WGA and 72.9% of the PGA group. Incontinence-free survival was significantly shorter in the PGA than in the WGA group (P= .047); however, no significant intergroup difference was observed in erectile dysfunction-free survival (P= .317). The postoperative adverse event rate was significantly lower in the PGA than in the WGA group (37.5% vs. 66.7%, P = .023). Of the total patients investigated, 43 (20.9%) required additional endoscopic surgery for bladder outlet obstruction, and the additional endoscopic surgery rate was significantly higher in the WGA than in the PGA group (35.2% vs. 15.8%, P = .005).

CONCLUSION

HIFU treatment was associated with acceptable oncological and fair functional outcomes in patients with localized PCa. Moreover, PGA was associated with significantly better clinical outcomes, including the faster recovery of urinary incontinence and adverse effects.

Salvage therapy for prostate cancer after radical prostatectomy

More than 40% of men with intermediate-risk or high-risk prostate cancer will experience a biochemical recurrence after radical prostatectomy. Clinical guidelines for the management of these patients largely focus on the use of salvage radiotherapy with or without systemic therapy. However, not all patients with biochemical recurrence will go on to develop metastases or die from their disease. The optimal pre-salvage therapy investigational workup for patients who experience biochemical recurrence should, therefore, include novel techniques such as PET imaging and genomic analysis of radical prostatectomy specimen tissue, as well as consideration of more traditional clinical variables such as PSA value, PSA kinetics, Gleason score and pathological stage of disease. In patients without metastatic disease, the only known curative intervention is salvage radiotherapy but, given the therapeutic burden of this treatment, importance must be placed on accurate timing of treatment, radiation dose, fractionation and field size. Systemic therapy also has a role in the salvage setting, both concurrently with radiotherapy and as salvage monotherapy.

Prostate minimally invasive procedures: complications and normal vs. abnormal findings on multiparametric magnetic resonance imaging (mpMRI)

Minimally invasive alternatives to traditional prostate surgery are increasingly utilized to treat benign prostatic hyperplasia and localized prostate cancer in select patients. Advantages of these treatments over prostatectomy include lower risk of complication, shorter length of hospital stay, and a more favorable safety profile. Multiparametric magnetic resonance imaging (mpMRI) has become a widely accepted imaging modality for evaluation of the prostate gland and provides both anatomical and functional information. As prostate mpMRI and minimally invasive prostate procedure volumes increase, it is important for radiologists to be familiar with normal post-procedure imaging findings and potential complications. This paper reviews the indications, procedural concepts, common post-procedure imaging findings, and potential complications of prostatic artery embolization, prostatic urethral lift, irreversible electroporation, photodynamic therapy, high-intensity focused ultrasound, focal cryotherapy, and focal laser ablation.

Role of multiparametric prostate MRI in the management of prostate cancer

INTRODUCTION

Prostate cancer has traditionally been diagnosed by an elevation in PSA or abnormal exam leading to a systematic transrectal ultrasound (TRUS)-guided biopsy. This diagnostic pathway underdiagnoses clinically significant disease while over diagnosing clinically insignificant disease. In this review, we aim to provide an overview of the recent literature regarding the role of multiparametric MRI (mpMRI) in the management of prostate cancer.

MATERIALS AND METHODS

A thorough literature review was performed using PubMed to identify articles discussing use of mpMRI of the prostate in management of prostate cancer.

CONCLUSION

The incorporation of mpMRI of the prostate addresses the shortcomings of the prostate biopsy while providing several other advantages. mpMRI allows some men to avoid an immediate biopsy and permits visualization of areas likely to harbor clinically significant cancer prior to biopsy to facilitate use of MR-targeted prostate biopsies. This allows for reduction in diagnosis of clinically insignificant disease as well as improved detection and better characterization of higher risk cancers, as well as the improved selection of patients for active surveillance. In addition, mpMRI can be used for selection and monitoring of patients for active surveillance and treatment planning during surgery and focal therapy.

Magnetic Resonance Imaging Assessment After Therapy in Prostate Cancer

Prostate cancer is the fifth leading cause of death worldwide. A variety of treatment options is available for localized prostate cancer and may range from active surveillance to focal therapy or whole gland treatment, that is, surgery or radiotherapy. Serum prostate-specific antigen levels are an important tool to monitor treatment success after whole gland treatment, unfortunately prostate-specific antigen is unreliable after focal therapy. Multiparametric magnetic resonance imaging of the prostate is rapidly gaining field in the management of prostate cancer and may play a crucial role in the evaluation of recurrent prostate cancer. This article will focus on postprocedural magnetic resonance imaging after different forms of local therapy in patients with prostate cancer.

Comparison of outcomes of salvage robot-assisted laparoscopic prostatectomy for post-primary radiation vs focal therapy

OBJECTIVES

To compare salvage robot-assisted laparoscopic prostatectomy (RALP) outcomes in patients who underwent radiation and those who underwent focal ablation as primary therapies.

PATIENTS AND METHODS

We evaluated 126 patients who underwent salvage RALPbetween 2008 and 2018. Of these, 94 (74.6%) received radiation and 32 focal ablation (25.4%) as primary therapy. These groups were compared with regard to clinical, oncological and functional outcomes. Kaplan-Meier curves and regression models were used to identify survival estimations and their predictors.

RESULTS

Before surgery, more patients were potent in the focal ablation group compared to the radiation group (46.9% vs 22.6%; P = 0.013). Peri-operative characteristics and complication rates were not significantly different between the two groups. Postoperative catheterization duration was shorter in the focal ablation group (mean 10 vs 16 days; P = 0.018). At final pathology, the focal ablation group had higher non-organ-confined disease (71% vs 50%; P = 0.042) and positive surgical margin (PSM) rates (43.8% vs 17%; P = 0.004) as compared to the radiation group; however, 5-year biochemical recurrence (BCR)-free survival rates were similar (59% vs 56%; P = 0.761). Postoperative 1-year full (no pads/day) and social (0-1 pad/day) continence rates were significantly higher in the focal ablation as compared to the radiation group (77.3% vs 39.2%, P = 0.002, and 87.5% vs 51.3%, P = 0.002, respectively). Multivariate analyses showed primary focal ablation and nerve-sparing to be predictors of postoperative continence. Erectile function was preserved in 13% and 27% of preoperatively potent patients in the radiation and focal ablation groups, respectively (P = 0.435). No predictors were identified for postoperative potency.

CONCLUSIONS

Radiation was associated with inferior functional outcomes after salvage RALP. Focal therapies were associated with higher non-organ-confined disease and PSMrates, with no significant difference in short-term BCR-free survival.

Feasibility and Initial Results: Fluciclovine Positron Emission Tomography/Ultrasound Fusion Targeted Biopsy of Recurrent Prostate Cancer

PURPOSE

We assessed the feasibility and cancer detection rate of fluciclovine (¹⁸F) positron emission tomography-ultrasound fusion targeted biopsy vs standard template biopsy in the same patient with biochemical failure after nonsurgical therapy for prostate cancer.

MATERIALS AND METHODS

A total of 21 patients with a mean ± SD prostate specific antigen of 7.4 ± 6.8 ng/ml and biochemical failure after nonoperative prostate cancer treatment underwent fluciclovine (¹⁸F) positron emission tomography-computerized tomography (mean 364.1 ± 37.7 MBq) and planning transrectal prostate ultrasound with 3-dimensional image reconstruction. Focal prostatic activity on positron emission tomography was delineated and co-registered with planning ultrasound. During the subsequent biopsy session computer generated 12-core template biopsies were performed and then fluciclovine defined targets were revealed and biopsied. Histological analysis of template and targeted cores were completed.

RESULTS

Template biopsy was positive for malignancy in 6 of 21 patients (28.6%), including 10 of 124 regions and 11 of 246 cores, vs targeted biopsy in 10 of 21 (47.6%), including 17 of 50 regions and 40 of 125 cores. Five of 21 patients had positive findings on targeted biopsy only and 1 of 21 had positive findings on template biopsy only. An additional case was upgraded from Grade Group 2 to 3 on targeted biopsy. Extraprostatic disease was detected in 8 of 21 men (38.1%) with histological confirmation in all 3 who underwent lesion biopsy.

CONCLUSIONS

Fluciclovine positron emission tomography real-time ultrasound fusion guidance for biopsy is feasible in patients with biochemical failure after nonsurgical therapy for prostate cancer. It identifies more recurrent prostate cancer using fewer cores compared with template biopsy in the same patient. Further study is required to determine in what manner targeted biopsy may augment template biopsy of recurrent prostate cancer.

Fluciclovine positron emission tomography in the setting of biochemical recurrence following local therapy of prostate cancer

Approximately one in five men will demonstrate biochemical recurrence (BCR) following local therapy for prostate cancer (PCa). Advanced imaging modalities including positron emission tomography (PET) imaging of various radiotracers have become more commonplace to visualize foci of disease recurrence. We performed a systematic review of the literature to describe current evidence in support of 18F-fluciclovine (Axumin) PET imaging in this clinical setting. An English literature search was conducted on PubMed/Medline for original investigations on 18F-fluciclovine PET for PCa. Boolean criteria included the terms: prostate, fluciclovine, FACBC and Axumin. Published articles meeting these criteria and their respective bibliographies and diagnostic modalities were included after review, when appropriate. Our literature review identified 93 articles. Among these, 18 met our inclusion criteria. Evidence suggests 18F-fluciclovine PET imaging is safe, well-tolerated and offers acceptable sensitivity and specificity for the detection of localized intraglandular and extraprostatic PCa foci in the setting of persistence or recurrence after primary treatment. Compared to other available PET radiotracers available, evidence suggests that 18F-fluciclovine may outperform ProstaScint and 11C-choline in this clinical setting. Furthermore, 18F-fluciclovine PET may aid guiding decision-making in regards to salvage therapy planning. Further investigation is warranted to validate these early findings and to further compare this agent to other available radiotracers in this setting.

Oligometastatic recurrent prostate cancer detects by fluorine-18-choline positron emission tomography/computed tomography in patients with prostate-specific antigen levels of up to 5 ng/ml

PURPOSE

The aim of this study was to assess the ability of fluorine-18-fluorocholine (F-FCH) PET/computed tomography (CT) to detect oligometastatic disease (OMD) in patients with early recurrence of prostate cancer (PC) [prostate-specific antigen (PSA)≤5 ng/ml].

PATIENTS AND METHODS

Between 2010 and 2016, 324 patients with PC and PSA levels of less than or equal to 5 ng/ml were recruited. The mean (SD) age of the patients was 71 (10) years. All patients were treated with a radical prostatectomy±lymphadenectomy. One-hundred and twenty-one patients were under hormonal therapy at the time of PET/CT, whereas 203 were not. The mean (SD) PSA at the time of PET/CT was 1.33 (1.19) ng/ml, the mean (SD) PSA doubling time (PSAdt) was 10 (12) months, and the mean (SD) PSA velocity (PSAvel) was 1.94 (3.31) ng/ml/year. The correlation between continuous and categorical data was assessed using Student's t-test or by analysis of variance and by the χ-test, respectively. Univariate and multivariate analysis was carried out for the identification of clinical variables able to predict the presence of OMD.

RESULTS

One-hundred and ninety-three patients had a negative F-FCH PET/CT, whereas 131 (40.4%) had a positive scan. Of these latter patients, 35 had a significant F-FCH uptake in the prostatic fossae, 59 in the lymph nodes, and 37 in bone. PSA levels were significantly different between patients with a positive than those with a negative scan (P<0.001). F-FCH PET/CT was negative in the majority of patients with a PSA of less than or equal to 1 (63.2%) ng/ml. More than 60% of patients with a PSAdt of less than or equal to 6 months had a positive F-FCH PET/CT scan for OMD. PSAvel was higher in patients with a positive scan than those with a negative finding. At univariate analysis, PSA level, PSAdt, and PSAvel were predictors of a positive F-FCH PET/CT for OMD, whereas on multivariate analysis, only PSA level and PSAdt were independent predictors (both P<0.01). Furthermore, PSAdt was the only independent predictor of OMD at the lymph node level.

CONCLUSION

In patients with early recurrence of PC, F-FCH PET/CT is able to detect OMD in 40% of cases. This finding has an important impact on the detection of PC recurrent lesions that could be treated by local therapy to achieve long-term survival or cure.

Prostate MR Imaging for Posttreatment Evaluation and Recurrence

Prostate multiparametric MR imaging (mpMRI) plays an important role in local evaluation after treatment of prostate cancer. After radical prostatectomy, radiation therapy, and focal therapy, mpMRI can be used to visualize normal post-treatment changes and to diagnose locally recurrent disease. An understanding of the various treatments and expected changes is essential for complete and accurate post-treatment mpMRI interpretation.

Computerized Planning of Prostate Cryosurgery and Shape Considerations

The current study aims to explore possible relationships between various prostate shapes and the difficulty in creating a computer-based plan for cryosurgery. This research effort is a part of an ongoing study to develop computational means in order to improve cryosurgery training and education. This study uses a computerized planner-a key building block of a recently developed prototype for cryosurgery training. The quality of planning is measured by the overall defect volume, a proprietary concept which refers to undercooled areas internal to the target region and overcooled areas external to it. Results of this study numerically confirm that the overall defect volume decreases with an increasing number of cryoprobes, regardless of the geometry of the prostate. However, the number of cryoprobes required to achieve the smallest possible defect may be unrealistically high (<30). Results of this study also demonstrate that the optimal cryoprobe layout is associated with a smaller defect for symmetric prostate geometries and, independently, for prostate models that better resemble a sphere. Furthermore, a smaller defect is typically achieved when the urethra passes through the center of the prostate model. This study proposes to create a cryoprobe convex hull for the purpose of initial planning, which is a subdomain similar in shape to the prostate but at a reduced size. Parametric studies indicate that a cryoprobe convex hull contracted by 7 to 9 mm in all directions from the prostate capsule serves as a quasi-optimal initial condition for planning, that is, a preselected number of cryoprobes placed in the cryoprobe convex hull yields favorable results for optimization. The cryoprobe convex hull could accelerate computer-based planning, while also being adopted as a concept for traditional cryosurgery training, when computerized means are absent.

Multiparametric Magnetic Resonance Imaging of Recurrent Prostate Cancer

There is growing consensus that multiparametric magnetic resonance imaging (mpMRI) is an effective modality in the detection of locally recurrent prostate cancer after prostatectomy and radiation therapy. The emergence of magnetic resonance (MR)-guided focal therapies, such as cryoablation, high-intensity focused ultrasound, and laser ablation, have made the use of mpMRI even more important, as the normal anatomy is inevitably altered and the detection of recurrence is made more difficult. The aim of this article is to review the utility of mpMRI in detecting recurrent prostate cancer in patients following radical prostatectomy, radiation therapy, and focal therapy and to discuss expected post-treatment mpMRI findings, the varied appearance of recurrent tumors, and their mimics.

The ability of 18F-choline PET/CT to identify local recurrence of prostate cancer

PURPOSE

To determine when 18F-choline PET/CT can truly identify local recurrence of prostate cancer.

METHODS

1031 patients from 3 European centers underwent (18)F-choline PET/CT (FCH PET/CT) for recurrent disease; 131 subjects (12.7%) showed a positive FCH uptake in the prostatic gland or prostatic fossa. Median age was 72 years (range 48-87 years), and the median PSA level at the time of FCH PET/CT scan was 4.41 ng/mL (0.22-18.13 ng/mL). 45 patients (34.4%) had a Gleason score (GS) >7, and the residual subjects had a GS ≤ 7. The assessment of true or false-positive FCH PET/CT findings was made by magnetic resonance imaging (n = 34) and/or biopsy in 75/131 cases. A χ (2) test and a Z Kolmogorov-Smirnov test were used to assess the correlation between clinical variables (age, PSA, GS, type of therapy) and FCH PET/CT findings.

RESULTS

FCH PET/CT resulted truly positive (TP) for recurrent disease in the prostatic gland/fossa in 59/75 patients (79%) and falsely positive (FP) in 16 subjects (21%). The median value of PSA at the time of FCH PET/CT scan was higher in TP as compared to FP, although not statistically significant (4.76 vs. 3.04 ng/mL p > 0.05). Similarly, median age, GS categories, and the type of therapy were similar between the two groups (p > 0.05). However, when matching GS categories and PSA values, we found that the number of patients with TP findings were higher in the case of a PSA > 2 ng/mL, independently from the GS (ranging between 74% and 92%). Conversely, FP rate ranged between 50% and 65% in patients with a PSA ≤ 2 ng/mL, especially in the case of GS ≤ 7, whereas FP was around 25% in those with a GS >7 and PSA > 2 ng/mL.

CONCLUSIONS

FCH PET/CT has a limited role in evaluation of prostatic gland/fossa recurrence, due to the physiological biodistribution of the radiopharmaceutical agent. However, in 70-90% of patients with a PSA >2 ng/mL, independently from GS, a focal FCH uptake is compatible with a true local recurrence.

Salvage radiation therapy following radical prostatectomy. A national Danish study

BACKGROUND

The purpose of this observational cohort study was to evaluate the outcome and prognostic factors following salvage radiotherapy (SRT) in a consecutive national cohort.

MATERIAL AND METHODS

Between 2006 and 2010, 259 patients received SRT in Denmark. Patient- and cancer-related characteristics were retrospectively retrieved from patient charts. The primary end point was biochemical progression-free survival (b-PFS).

RESULTS

At the end of follow-up, 51% of the patients displayed a prostate-specific antigen (PSA) level <0.1 ng/ml. The three-year b-PFS rate for the total cohort was 57.0%. Nearly half of the patients (44%) received androgen deprivation therapy (ADT) in combination with SRT. Positive surgical tumour margins (p = 0.025) and ADT (p = 0.001) were the only markers independently correlated with b-PFS. In patients who received SRT without ADT, both a pre-SRT PSA level ≤0.5 ng/ml (p = 0.003) and pathological tumour stage T1-T2 (p = 0.036) independently correlated with b-PFS. Moreover, a duration between radical prostatectomy (RP) and SRT ≤29 months (p = 0.035) independently correlated with b-PFS in patients treated with ADT in combination with RT.

CONCLUSIONS

In patients treated for biochemical failure after RP, positive surgical tumour margins and PSA levels ≤0.5 ng/mL at the time of SRT were associated with a favourable outcome. Despite less favourable tumour characteristics, patients receiving SRT and ADT demonstrated improved b-PFS, and in particular, patients with PSA levels >0.2 ng/ml benefitted from additional ADT.

Use of androgen deprivation therapy as salvage treatment after primary therapy for clinically localized prostate cancer

PURPOSE

The optimal use of androgen deprivation therapy as salvage treatment (sADT) for men after initial prostatectomy or radiotherapy for clinically localized prostate cancer is undefined. We describe patterns of sADT use and investigate clinical and sociodemographic characteristics of insured men who received sADT versus surveillance in managed care settings.

METHODS

Using comprehensive electronic health records and cancer registry data from three integrated health plans, we identified all men with newly diagnosed clinically localized prostate cancer between 1995 and 2009 who received either prostatectomy (n = 16,445) or radiotherapy (n = 19,531) as their primary therapy. We defined sADT based on the timing of ADT following primary therapy and stage of cancer. We fit Cox proportional hazard models to identify sociodemographic characteristics and clinical factors associated with sADT.

RESULTS

With a median follow-up of 6 years (range 2-15 years), 13 % of men who underwent primary prostatectomy or radiotherapy received sADT. After adjusting for selected covariates, sADT was more likely to be used in men who were older (e.g., HR 1.70, 95 % CI 1.48-1.96 or HR 1.33, 95 % CI 1.17-1.52 for age 70+ relative to age 35-59 for primary prostatectomy or radiotherapy, respectively), were African-American, had a short PSA doubling time, had a higher pre-treatment risk of progression, had more comorbidities, and received adjuvant ADT for initial disease.

CONCLUSIONS

In men with localized prostate cancer in community practice initially treated with prostatectomy or radiotherapy, sADT after primary treatment was more frequent for men at greater risk of death from prostate cancer, consistent with practice guidelines.

Value of bimodal (18)F-choline-PET/MRI and trimodal (18)F-choline-PET/MRI/TRUS for the assessment of prostate cancer recurrence after radiation therapy and radical prostatectomy

Between 27% and 53% of all patients who undergo radical prostatectomy (RP) or radiation therapy (RT) as the first-line treatment of prostate cancer (PCa) develop a biochemical recurrence. Imaging plays a pivotal role in restaging by helping to distinguish between local relapse and metastatic disease (i.e., lymph-node and skeletal metastases). At present, the most promising tools for assessing PCa patients with biochemical recurrence are multiparametric magnetic resonance imaging (mpMRI) and positron emission tomography (PET)/computed tomography (CT) with radio-labeled choline derivatives. The main advantage of mpMRI is its high diagnostic accuracy in detecting local recurrence, while choline-PET/CT is able to identify lymph-node metastases when they are not suspicious on morphological imaging. The most recent advances in the field of fusion imaging have shown that multimodal co-registration, synchronized navigation, and combined interpretation are more valuable than the individual; separate assessment offered by different diagnostic techniques. The objective of the present essay was to describe the value of bimodal choline-PET/mpMRI fusion imaging and trimodal choline-PET/mpMRI/transrectal ultrasound (TRUS) in the assessment of PCa recurrence after RP and RT. Bimodal choline-PET/mpMRI fusion imaging allows morphological, functional, and metabolic information to be combined, thereby overcoming the limitations of each separate imaging modality. In addition, trimodal real-time choline-PET/mpMRI/TRUS fusion imaging may be useful for the planning and real-time guidance of biopsy procedures in order to obtain histological confirmation of the local recurrence.

The clinical role of multimodality imaging in the detection of prostate cancer recurrence after radical prostatectomy and radiation therapy: past, present, and future

Detection of the recurrence sites in prostate cancer (PCa) patients affected by biochemical recurrence after radical prostatectomy (RP) and radiation therapy (RT) is still a challenge for clinicians, nuclear medicine physicians, and radiologists. In the era of personalised and precision care, this task requires the integration, amalgamation, and combined analysis of clinical and imaging data from multiple sources. At present, multiparametric Magnetic Resonance Imaging (mpMRI) and choline–positron emission tomography (PET) are giving encouraging results; their combination allows the effective detection of local, lymph nodal, and skeletal recurrences at low PSA levels. Future diagnostic perspectives include the clinical implementation of PET/MRI scanners, multimodal fusion imaging platforms for retrospective co-registration of PET and MR images, real-time transrectal ultrasound/mpMRI fusion imaging, and novel organ-specific PET radiotracers.

Accelerated hypofractioned postoperative radiotherapy for prostate cancer: a prospective phase I/II study

AIMS

To present the initial findings of a single institution, phase I/II study investigating hypofractionated radiotherapy in patients undergoing post-prostatectomy treatment.

MATERIALS AND METHODS

Patients requiring postoperative radiotherapy were prospectively enrolled. Dose was prescribed to the prostate bed with 51 Gy in 17 daily fractions. Androgen deprivation was optional. Acute and late gastrointestinal/genitourinary toxicity were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0 and quality of life was assessed using the Expanded Prostate Cancer Index Composite evaluation tool. Prostate-specific antigen (PSA) was evaluated at every follow-up.

RESULTS

Thirty patients were enrolled between 2009 and 2011. The median age was 65 years and most had Gleason 7 disease (86%) with pT2c or pT3a (82%). Positive margins were documented in 67% of the patients. The median pre-treatment PSA was 0.12 ng/ml. The median follow-up was 24 months. Overall toxicity was low, with >80% of patients having ≤ grade 1 acute toxicity in both genitourinary and gastrointestinal realms. Similarly, only two patients (6%) experienced grade 2/3 late gastrointestinal/genitourinary toxicity. Quality of life scores were also indicative of a well-tolerated treatment. PSA failure was seen in five patients (17%).

CONCLUSIONS

We present a hypofractionated schedule of postoperative prostate radiotherapy that is both well tolerated in terms of both toxicity and quality of life measures. Initial PSA control is encouraging. Further evaluation with a longer follow-up and a larger cohort is warranted.

Early biochemical relapse after radical prostatectomy: which prostate cancer patients may benefit from a restaging 11C-Choline PET/CT scan before salvage radiation therapy?

The aim of the study was to assess which factors may influence (11)C-choline PET/CT detection rate in a population of recurrent prostate cancer (PCa) patients listed for salvage radiation therapy (S-RT) in an early phase of biochemical relapse, to select which patients could obtain the most benefit by performing restaging (11)C-choline PET/CT before S-RT.

METHODS

The study comprised 605 patients, treated with radical prostatectomy (RP) with curative intent for PCa who showed rising PSA levels after primary therapy and listed for S-RT. Prostate-specific antigen (PSA) values were >0.2 ng/mL and <2 ng/mL (mean, 1.05 ng/mL; median, 1.07 ng/mL; range, 0.2-2 ng/m; SD, ±0.59). All patients were classified as N0 after RP. Seventeen of 605 patients received adjuvant RT together with RP, whereas 148 of 605 patients received androgen-deprivation therapy (ADT) at the time of PET/CT. PSA, PSA kinetics, Gleason score, age, time to biochemical relapse, ADT, and initial tumor stage were statistically analyzed to assess which factor could influence PET/CT positivity and the detection of local versus distant relapse.

RESULTS

(11)C-choline PET/CT was positive in 28.4% of patients (172/605). Eighty-three of 605 patients were positive in the pelvis (group A), distant metastasis (group B) were detected in 72 of 605 patients, and local and distant sites of relapse were detected in 17 of 605 patients (group C). At multivariate analysis, PSA, PSA doubling time (PSAdt), and ongoing ADT were significant predictors for positive scan results, whereas PSA and PSAdt were significantly related to distant relapse detection (P < 0.05). At the receiver-operating-characteristic analysis, a PSA value of 1.05 ng/mL and PSAdt of 5.95 mo were determined to be the optimal cutoff values in the prediction of a positive (11)C-choline PET/CT scan, with an area under the curve (AUC) of 0.625 for PSA and 0.677 for PSAdt.

CONCLUSION

(11)C-choline PET/CT may be suggested before S-RT during the early phase of biochemical relapse, to select patients who may benefit from this aggressive treatment. Particularly, patients showing fast PSA kinetics or PSA increasing levels despite ongoing ADT should be studied with (11)C-choline PET/CT before S-RT, considering the higher probability to detect positive findings outside the pelvis.

Evaluation of 3 T pelvic MRI imaging in prostate cancer patients receiving post-prostatectomy IMRT

PURPOSE

The purpose of the study was to evaluate the utility of a 3 T pelvic magnetic resonance imaging (MRI) in detecting a local recurrence in post-prostatectomy prostate cancer patients prior to receiving adjuvant or salvage intensity-modulated radiation therapy (IMRT).

METHODS

Ninety prostate cancer patients status post-prostatectomy with rising prostate-specific antigen (PSA) had a 3 T pelvic MRI prior to IMRT. The following variables were analyzed for predicting positive findings on MRI: initial presenting and initial post-op PSA, PSA at the time of imaging, PSA velocity, surgical margins, Gleason score, pathological stage, pre-RT digital rectal examination, and type of surgical prostatectomy.

RESULTS

The only significant variable predictive of a positive MRI was positive margins. Specifically, 15 of 46 (33 %) patients with positive margins had a positive MRI, while 5 of 44 (11 %) patients with negative margins had a positive MRI. In the MRI positive group, the location of the positive findings on MRI corresponded with the pathology report in 9 of 12 (75 %) cases.

CONCLUSION

Post-prostatectomy patients with pathologic positive margins are three times more likely to have positive findings on a 3 T MRI.

A paradigm shift from anatomic to functional and molecular imaging in the detection of recurrent prostate cancer

Approximately a third of men with localized prostate cancer who are treated with external beam radiation therapy (EBRT) or radical prostatectomy (RP) develop biochemical failure (BF). Presumably, BF will progress to distant metastasis and prostate cancer-specific mortality in some patients over subsequent years. Accurate detection of recurrent disease is important because it allows for appropriate treatment selection (e.g., local vs systemic therapy) and early delivery of therapy (e.g., salvage EBRT), which affect patient outcome. In this article, we discuss the paradigm shift in imaging technology in the detection of recurrent prostate cancer. First, we discuss the commonly used morphological and anatomical imaging modalities and their role in the post-RP and post-EBRT settings of BF. Second, we discuss the accuracy of functional and molecular imaging techniques, many of which are under investigation. Further studies are needed to establish the role of imaging techniques for detection of cancer recurrence and clinical decision-making.

11C-choline PET/CT detects the site of relapse in the majority of prostate cancer patients showing biochemical recurrence after EBRT

PURPOSE

The aim of this retrospective study was to evaluate the usefulness and the detection rate of (11)C-choline PET/CT in a population of patients with prostate cancer (PC), exclusively treated with external beam radiotherapy (EBRT) as primary treatment, who showed biochemical relapse.

MATERIALS AND METHODS

We enrolled 140 patients showing a serum PSA level >2 ng/mL (mean 8.6 ng/mL, median 5 ng/mL, range 2 - 60 ng/mL). All patients had been treated with EBRT to the prostate gland and prostatic fossa with doses ranging from 70 to 76 Gy in low-risk patients (T1/T2 and/or serum PSA <10 ng/mL) and escalating to >76 Gy (range 76 - 81 Gy) in high-risk patients (T3/T4 and/or serum PSA >10 ng/mL). Of the 140 patients, 53 were receiving androgen deprivation therapy at the time of the scan. All positive (11)C-choline PET/CT findings were validated by transrectal ultrasound-guided biopsy or at least 12 months of follow-up with contrast-enhanced CT, MR, bone scintigraphy or a repeated (11)C-choline PET/CT scan. The relationships between the detection rate of (11)C-choline PET/CT and the factors PSA level, PSA kinetics, Gleason score, age, time to relapse and SUV max in patients with positive findings were analysed.

RESULTS

(11)C-Choline PET/CT detected the site of relapse in 123 of the 140 patients with a detection rate of 87.8 % (46 patients showed local relapse, 31 showed local and distant relapse, and 46 showed only distant relapse). In patients with relapse the mean serum PSA level was 9.08 ng/mL (median 5.1 ng/mL, range 2 - 60 ng/mL), the mean PSA doubling time was 5.6 months (median 3.5 months, range 0.4 - 48 months), and the mean PSA velocity was 15 ng/mL/year (median 8.8 ng/mL/year, range 0.4 - 87 ng/mL/year). Of the 123 patients with relapse, 77 (62.6 %) showed distant relapse with/without local relapse, and of these 77, 31 (40.2 %) showed oligometastatic disease (one or two distant lesions: lymph node lesions only in 16, bone lesions only in 14, and lymph node lesions and bone lesions in 1). In univariate and multivariate analyses PSA kinetics was the only variable affecting (11)C-choline PET/CT detection rate. A significant correlation between PSA kinetics and site of recurrence (local relapse only vs. distant metastasis) was also observed.

CONCLUSION

The detection rate of (11)C-choline PET/CT in patients with PC showing biochemical recurrence after EBRT as primary treatment is relatively high (87.8 %). (11)C-Choline PET/CT was able to detect extraprostatic disease in the 62.6 % of patients. Considering this high detection rate, (11)C-choline PET/CT could have clinical usefulness in the management of these PC patients, but this should be confirmed in future studies.

11C choline PET guided salvage radiotherapy with volumetric modulation arc therapy and hypofractionation for recurrent prostate cancer after HIFU failure: preliminary results of tolerability and acute toxicity

The purpose of this work was to evaluate tolerance, feasibility and acute toxicity in patients undergoing salvage radiotherapy after high-intensity focused ultrasound (HIFU) failure. From 2005 to 2011 a total of 15 patients were treated with HIFU as primary radical treatment. Between July 2011 and February 2013, all 15 patients presented biochemical relapse after HIFU and 11C choline PET documenting intrapostatic-only failure. Salvage EBRT was performed with moderate hypofractionation schedule in 28 fractions with volumetric modulation arc therapy (VMAT). Genito-urinary (GU) and rectal and bowel toxicity were scored by common terminology criteria for adverse events version 4 (CTCAE V.4) scale. Biochemical response was assessed by ASTRO Phoenix criteria. Median age of patients was 67 years (range: 53-85). The median Gleason score was 7 (range: 6-9). The median prostate specific antigen (PSA) at the time of biochemical relapse after HIFU was 5.2 ng/mL (range: 2-64.2). Seven of the 15 patients received androgen deprivation therapy (ADT) started after HIFU failure, interrupted before 11C choline PET and radiotherapy. Median prescribed dose was 71.4 Gy (range: 71.4-74.2 Gy) in 28 fractions. No radiation related major upper gastrointestinal (GI), rectal and GU toxicity were experienced. GU, acute grade 1 and grade 2 toxicities were recorded in 7/15 and 4/15 respectively; bowel acute grade 1 and grade 2 toxicities in 4/15 and 1/15; rectal acute grade 1 and grade 2 toxicities in 3/15 and 2/15 respectively. No grade 3 or greater acute or late toxicities occurred. Biochemical control was assessed in 12/15 (80%) patients. With a median follow up of 12 months, three out of 15 patients, with biochemical relapse, showed lymph-nodal recurrence. Our early clinical results and biochemical data confirm the feasibility and show a good tolerance of the 11C choline PET guided salvage radiation therapy after HIFU failure. The findings of low acute toxicity is encouraging, but longer follow-up is needed to assess late toxicity and definitive outcomes.

Diagnostic imaging work-up for disease relapse after radical treatment for prostate cancer: how to differentiate local from systemic disease? The urologist point of view

About 40% of all patients undergoing radical treatment for localized prostate cancer (PCa) develop biochemical relapse (BCR) during lifetime but only 10-20% of them will show clinically detectable recurrences. Prostatic bed, pelvic or retroperitoneal lymph nodes (LN) and bones (especially the spine) are the sites where we must focus our attention in the early phase of PSA relapse. Time to PSA relapse, PSA kinetics, pathological Gleason score and pathological stage are the main factors related to the likelihood of local vs. distant relapse. Before an extensive diagnostic work-up in patients with BCR, is mandatory to understand if there is a therapeutic consequence or not for the patient. Current imaging techniques have some potential but many limits are yet encountered in the diagnosis of disease relapse. Transrectal ultrasound (TRUS) and Multiparametric Magnetic Resonance Imaging (MRI) have low accuracy in the detection of the recurrence. Today, Choline PET/CT may visualize the site of recurrence earlier, with better accuracy than conventional imaging, in a single step and even in the presence of low PSA level. In recent years, the new radiotracer (18)F-FACBC has been proposed as a possible alternative radiopharmaceutical to detect PCa relapse. From a clinical point of view, first clinical studies showed very promising and reproducible results with an improvement in sensitivity is about 20-25% with respect to Choline PET/CT, rendering the FACBC the possible radiotracer of the future for PCa. In conclusion, many improvements have been recently achieved in imaging techniques for PCa restaging, essentially in Nuclear Medicine and MRI, but negative results remain in many cases. Low sensitivity, costs, availability of technologies and confirmation of the results remain the major limitations in most cases.

Predictors of biochemical failure in patients undergoing prostate whole-gland salvage cryotherapy: a novel risk stratification model

What's known on the subject? and what does the study add?: Previous studies have identified the most important prognostic factors of the likely outcomes of salvage prostate whole-gland ablation, including initial clinical stage, biopsy Gleason score, and PSA (total and doubling time). There is potential for further optimization of candidate selection for salvage cryoablation with curative intent and nadir PSA achieved after whole-gland cryotherapy may provide additional prognostic value. The study shows that the most important prognostic factors of biochemical progression-free survival for patients who have undergone whole-gland salvage prostate cryotherapy are nadir PSA achieved after therapy and pre-therapy biopsy Gleason score. Based on these two prognostic variables, we have identified risk stratification groups (low, intermediate and high) which help predict the expected outcomes of salvage whole-gland prostate cryotherapy in a given patient. This risk stratification constitutes a useful clinical tool in defining which patients maybe best suited for this local salvage treatment method.

OBJECTIVE

To assess the prognostic variables predicting the risk of biochemical progression-free survival (bPFS) after salvage prostate whole-gland cryotherapy using the Phoenix definition of bPFS.

PATIENTS AND METHODS

A total of 132 patients underwent prostate whole-gland salvage cryotherapy with curative intent. No patient underwent neoadjuvant/adjuvant hormonal ablative therapy, and all had extended post-salvage prostate-specific antigen (PSA) follow-up data. Cox univariate and multivariate logistic regression analyses of potential predictors of bPFS were conducted. Kaplan-Meier analyses of bPFS was also performed.

RESULTS

At a mean (range) follow-up of 4.3 (0.9-12.7) years, the median (range) post-cryotherapy nadir PSA achieved was 0.17 (0-33.9) ng/mL. On multivariate analysis, predictors of bPFS were nadir PSA post-cryotherapy and pre-salvage biopsy Gleason score (P < 0.001 and 0.009, respectively). Risk stratification groups (low, intermediate and high) were developed based on the presence of zero, one or two adverse risk factors, the risk factors being either a nadir PSA >2.5 ng/mL or biopsy Gleason score ≥ 7, with the Kaplan-Meier bPFS curves of these risk groups being significantly different (P = 0.02 and <0.001, respectively).

CONCLUSIONS

Post-salvage nadir PSA and pre-salvage biopsy Gleason score are important predictors of outcome in this patient cohort. Low-, intermediate- and high-risk groups can be determined based on these variables and can define patients best suited for prostate cryotherapy.

Management of biochemical recurrence after primary treatment of prostate cancer: a systematic review of the literature

CONTEXT

Despite excellent cancer control with the treatment of localized prostate cancer (PCa), some men will experience a recurrence of disease. The optimal management of recurrent disease remains uncertain.

OBJECTIVE

To systematically review recent literature regarding management of biochemical recurrence after primary treatment for localized PCa.

EVIDENCE ACQUISITION

A comprehensive systematic review of the literature was performed from 2000 to 2012 to identify articles pertaining to management after recurrent PCa. Search terms included prostate cancer recurrence, salvage therapy, radiorecurrent prostate cancer, post HIFU, post cryoablation, postradiation, and postprostatectomy salvage. Studies were selected according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and required to provide a comprehensive description of primary and secondary treatments along with outcomes.

EVIDENCE SYNTHESIS

The data from 32 original publications were reviewed. The most common option for local salvage therapy after radical prostatectomy (RP) was radiation. Options for local salvage therapy after primary radiation included RP, brachytherapy, and cryotherapy. Different definitions of recurrence and risk profiles among patients make comparative assessment among salvage treatment modalities difficult. Triggers for intervention and factors predicting response to salvage therapy vary.

CONCLUSIONS

Radiation therapy (RT) after RP can provide durable prostate-specific antigen (PSA) responses in a sizeable percentage of men, especially when given early (ie, PSA <1 ng/ml). Though a few studies suggest improvements in mortality, prospective randomized trials are needed and underway. The role of salvage treatment after RT is less clear.

Analysis of intraprostatic therapeutic effects in prostate cancer patients using [(11)C]-choline pet/ct after external-beam radiation therapy

PURPOSE

The objective of the present study was to analyze, with relatively high sensitivity and specificity, uptake properties of [(11)C]-choline in prostate cancer patients by means of positron-emission tomography (pet)/computed tomography (ct) imaging using objectively defined pet parameters to test for statistically significant changes before, during, and after external-beam radiation therapy (ebrt) and to identify the time points at which the changes occur.

METHODS

The study enrolled 11 patients with intermediate-risk prostate cancer treated with ebrt, who were followed for up to 12 months after ebrt. The [(11)C]-choline pet scans were performed before treatment (baseline); at weeks 4 and 8 of ebrt; and at 1, 2, 3, 6, and 12 months after ebrt.

RESULTS

Analysis of [(11)C]-choline uptake in prostate tissue before treatment resulted in a maximum standardized uptake value (suvmax) of 4.0 ± 0.4 (n = 11) at 40 minutes after injection. During week 8 of ebrt, the suvmax declined to 2.9 ± 0.1 (n = 10, p < 0.05). At 2 and 12 months after ebrt, suvmax values were 2.3 ± 0.3 (n = 10, p < 0.01) and 2.2 ± 0.2 (n = 11, p < 0.001) respectively, indicating that, after ebrt, maximum radiotracer uptake in the prostate was significantly reduced. Similar effects were observed when analyzing the tumour:muscle ratio (tmr). The tmr declined from 7.4 ± 0.6 (n = 11) before ebrt to 6.1 ± 0.4 (n = 11, nonsignificant) during week 8 of ebrt, to 5.6 ± 0.03 (n = 11, p < 0.05) at 2 months after ebrt, and to 4.4 ± 0.4 (n = 11, p < 0.001) at 12 months after ebrt.

CONCLUSIONS

Our study demonstrated that intraprostatic [(11)C]-choline uptake in the 11 analyzed prostate cancer patients significantly declined during and after ebrt. The pet parameters SUVmax and tmr also declined significantly. These effects can be detected during radiation therapy and up to 1 year after therapy. The prognostic value of these early and statistically significant changes in intraprostatic [(11)C]-choline pet avidity during and after ebrt are not yet established. Future studies are indicated to correlate changes in [(11)C]-choline uptake parameters with long-term biochemical recurrence to further evaluate [(11)C]-choline pet changes as a possible, but currently unproven, biomarker of response.

Imaging-guided prostate biopsy: conventional and emerging techniques

Transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations owing to the operator's inability in most cases to directly visualize and target prostate lesions. Magnetic resonance (MR) imaging of the prostate overcomes many of these limitations by directly depicting areas of abnormality and allowing targeted biopsies. Accuracy in the detection of prostate cancer is improved by the combined use of standard T2-weighted MR imaging and advanced MR imaging techniques such as diffusion-weighted imaging, dynamic contrast-enhanced imaging, and MR spectroscopy. Suspicious-appearing regions of the prostate seen on MR images can be targeted at real-time transrectal US-guided biopsy to improve the diagnostic yield. MR imaging also can be performed for real-time guidance of transrectal prostate biopsy. Studies among patients who underwent at least one transrectal US-guided biopsy with a negative result before undergoing an MR imaging-guided biopsy showed improved detection rates with MR imaging-guided biopsy in comparison with the detection rates achieved with a repeat transrectal US-guided biopsy; however, MR imaging-guided biopsy is a more time-consuming procedure. A technique known as fused MR imaging- and transrectal US-guided biopsy, which relies on the coregistration of previously acquired MR images with real-time transrectal US images acquired during the procedure, shows promise but is limited by deformation of the prostate; this limitation is the subject of ongoing investigation. Another technique that is currently under investigation, MR imaging-guided prostate biopsy with robotic assistance, may one day help improve the accuracy of biopsy needle placement.

[Multiparametric prostate MRI for follow-up monitoring after radiation therapy]

CLINICAL/METHODICAL ISSUE

Radiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options.

STANDARD RADIOLOGICAL METHODS

For detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice.

PERFORMANCE

Good results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date.

PRACTICAL RECOMMENDATIONS

As the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.

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.