Advanced imaging for the early diagnosis of local recurrence prostate cancer after radical prostatectomy

Recurrent prostate cancer: combined role for MRI and PSMA-PET in 68Ga-PSMA-11 PET/MRI

OBJECTIVES

To investigate the specific strengths of MRI and PET components in 68Ga-PSMA-11 PET/MRI for staging of patients with biochemically recurrent prostate cancer (PCa).

METHODS

Patients with biochemical recurrence of PCa and contrast-enhanced whole-body 68Ga-PSMA-11 PET/MRI including a dedicated pelvic multiparametric MRI were included in this retrospective study. Imaging datasets of MRI and PET were evaluated separately regarding local PCa recurrence (Tr), pelvic lymph node metastases (N1), distant lymph node metastases (M1a), bone metastases (M1b), and soft tissue metastases (M1c) according to PROMISE version 1. Data evaluation was performed patient- and region-/lesion-based. Cox regression revealed a PSA of 1.69 ng/mL as a cut-off for subgroup analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were evaluated for each image component. Differences in staging accuracy were assessed using the Wilcoxon and McNemar test.

RESULTS

Altogether 102 patients (mean aged 68 ± 8 years, median PSA 1.33 ng/mL) were included. PCa was found in 70/102 (68%) patients. Accuracy of MRI in the detection of Tr, N1, M + , M1a, and M1b was 100%, 79%, 90%, 97%, and 95% for PSA < 1.69 ng/mL and 100%, 87%, 87%, 91%, and 96% for PSA > 1.69 ng/mL. Accuracy of 68Ga-PSMA-11 PET was 93%, 97%, 93%, 98%, and 100% for PSA < 1.69 ng/mL and 87%, 91%, 96%, 100%, and 96% for PSA > 1.69 ng/mL.

CONCLUSIONS

Combined assessment of 68Ga-PSMA-11 PET/MRI improves tumor localization in men with biochemical recurrence. The MRI detected local recurrence of PCa more often whereas 68 Ga-PSMA-11 PET detected lymph node metastases more often, especially for PSA < 1.69 ng/mL.

CLINICAL RELEVANCE STATEMENT

This study gives a scientific baseline to improve the understanding and reading of 68Ga-PSMA-11 PET/MRI imaging in patients with biochemically recurrent PCa by showing the specific strength of each imaging component.

KEY POINTS

• Combining the individual modality strengths of 68Ga-PSMA-11 PET/MRI improves tumor localization in men with biochemical recurrence of prostate cancer. • MRI component of 68 Ga-PSMA-11 PET/MRI shows its strength in detecting local recurrence of prostate cancer, especially at PSA < 1.69 ng/mL. • 68 Ga-PSMA-11 PET component shows its strength in detecting local and distant lymph node metastases, especially at PSA < 1.69 ng/mL.

Prostate Magnetic Resonance Imaging Using the Prostate Imaging for Recurrence Reporting (PI-RR) Scoring System to Detect Recurrent Prostate Cancer: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Prostate Imaging for Recurrence Reporting (PI-RR) was introduced in 2021 to standardize the interpretation and reporting of multiparametric magnetic resonance imaging (MRI) for prostate cancer following whole-gland treatment. The system scores image on a scale from 1 to 5 and has shown promising results in single-center studies. The aim of our systematic review and meta-analysis was to assess the diagnostic performance of the PI-RR system in predicting the likelihood of local recurrence after whole-gland treatment.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for diagnostic test accuracy were followed. Relevant databases were searched up to December 2023. Primary studies met the eligibility criteria if they reported MRI diagnostic performance in prostate cancer recurrence using PI-RR. Diagnostic performance for MRI was assessed using two different cutoff points (≥3 or ≥4 for positivity according to the PI-RR system). A meta-analysis with a random-effects model was used to estimate pooled sensitivity and specificity values.

KEY FINDINGS AND LIMITATIONS

Sixteen articles were identified for full-text reading, of which six were considered eligible, involving a total of 467 patients. Using a cutoff of PI-RR ≥3 (4 studies) for recurrent disease, the sensitivity was 77.8% (95% confidence interval [CI] 69.9-84.1%) and the specificity was 80.2% (95% CI 58.2-92.2%). Using a cutoff of PI-RR ≥4 (4 studies), the sensitivity was 61.9% (95% CI 35.6-82.7%) and the specificity was 86.6% (95% CI 75.1-93.3%). Overall, the inter-rater agreement varied from fair to excellent.

CONCLUSIONS AND CLINICAL IMPLICATIONS

PI-RR is accurate in detecting local recurrence after whole-gland treatment for prostate cancer and shows fair-to-good to excellent inter-reader agreement. Overall, a PI-RR cutoff of ≥3 showed high sensitivity and specificity.

PATIENT SUMMARY

We reviewed studies that reported on how good MRI scans using a scoring system called PI-RR were in detecting recurrence of prostate cancer. We found that this system shows good performance, with fair to excellent agreement between different radiologists.

Systemic Therapy for Metastatic Hormone-Sensitive Prostate Cancer: A Randomized Controlled Trial-Based Network Meta-Analysis

Objective

To compare the effects of different treatment strategies for metastatic hormone-sensitive prostate cancer (mHSPC) using a network meta-analysis.

Methods

English databases (PubMed, Embase, and medRxiv) and Chinese databases (Wanfang and CNKI) were searched for randomized controlled trials (RCTs) on the treatment of mHSPC from inception to June 1, 2021. The overall survival (OS) and failure-free survival (FFS) reported by the included studies were extracted from each study for network meta-analysis. Moreover, the priority ranks of the treatment methods were determined.

Results

A total of 18 RCTs with 14,682 patients were included in this study. Androgen-deprivation therapy (ADT) + apalutamide (APA) showed the highest probability of improving the OS (96.2%) and FFS (68.0%). In addition, the patients were stratified into ten subgroups as follows: low/high tumor burden (CHAARTED criteria); Gleason score ≤7/≥8; Eastern Cooperative Oncology Group (ECOG) = 0/≥1; with/without prechemotherapy; and cooperative with/without concomitant radiotherapy. For the improvement of OS, the leading treatments were as follows: (1) ADT + enzalutamide (ENZA) (64.1%)/ADT + abiraterone acetate + prednisone (AAP) (54.3%); (2) ADT + ENZA (41.9%)/ADT + APA (39.2%); (3) ADT + ENZA (39.2%)/ADT + APA (32.1%); (4) ADT + radiotherapy (51%)/ADT + ENZA (76.7%); (5) ADT + AAP (51%)/ADT + AAP (60%).

Conclusion

Three endocrine therapy drugs, abiraterone, enzalutamide, and APA, exhibited the best effects in improving the OS and FFS in all patients and subgroups; however, APA had the most prominent treatment effects. Therefore, ADT + APA should be applied as the common treatment for patients with HSPC based on objective and clinical conditions. Trial Registration. This meta-analysis has been registered on the PROSPERO website (Trial number: https://www.crd.york.ac.uk/prospero/CRD42020221062).

Imaging Biochemical Recurrence After Prostatectomy: Where Are We Headed?

OBJECTIVE. In this article, we discuss the evolving roles of imaging modalities in patients presenting with biochemical recurrence after prostatectomy. CONCLUSION. Multiple imaging modalities are currently available to evaluate patients with prostate cancer presenting with biochemical recurrence after prostatectomy. Multiparametric MRI (mpMRI) focuses on the postsurgical bed as well as regional lymph nodes and bones. PET/CT studies using ¹⁸F-fluciclovine, ¹¹C-choline, and prostate-specific membrane antigen (PSMA) ligands are useful in detecting locoregional and distant metastasis. Multiparametric MRI is preferred for patients with low risk of metastasis for localizing recurrence in prostate bed as well as pelvic lymph node and bone recurrence. Moreover, mpMRI aids in guiding biopsy and additional salvage treatments. For patients with high risk of metastatic disease, both mpMRI and whole-body PET/CT may be performed. PET/MRI using ⁶⁸Ga-PSMA has potential to enable a one-stop shop for local recurrence and metastatic disease evaluation, and clinical trials of PET/MRI are ongoing.

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.

Management of Advanced and Metastatic Prostate Cancer: A Need for a Sub-Saharan Guideline

The estimated incidence rate of prostate cancer in Africa was 22.0/100,000 in 2016. The International Agency for Research on Cancer (IARC) has cited prostate cancer as a growing health threat in Africa with approximated 28,006 deaths in 2010 and estimated 57,048 deaths in 2030. The exact incidence of advanced and metastatic prostate cancer is not known in sub-Saharan Africa. Hospital-based reports from the region have shown a rising trend with most patients presenting with advanced or metastatic disease. The management of advanced and metastatic prostate cancer is challenging. The available international guidelines may not be cost-effective for an African population. The most efficient approach in the region has been surgical castration by bilateral orchidectomy or pulpectomy. Medical androgen deprivation therapy is expensive and may not be available. Patients with metastatic castrate-resistant prostate cancer tend to be palliated due to the absence or cost of chemotherapy or second-line androgen deprivation therapy in most of Africa. A cost-effective guideline for developing nations to address the rising burden of advanced prostate cancer is warranted at this moment.

Combining Diagnostic Imaging and Pathology for Improving Diagnosis and Prognosis of Cancer

In the era of personalized medicine, the management of oncological patients requires a translational and multidisciplinary approach. During early phases of cancer development, biochemical alterations of cell metabolism occur much before the formation of detectable tumour masses. Current molecular imaging techniques, targeted to the study of molecular kinetics, employ molecular tracers capable of detecting cancer lesions with both high sensitivity and specificity while also providing essential information for both prognosis and therapy. On the contrary, complementary and crucial information is provided by histopathological examination and ancillary techniques such as immunohistochemistry. Thus, the successful collaboration between diagnostic imaging and anatomic pathology can represent a fundamental step in the "tortuous" but decisive path towards personalized medicine.

Prostate cancer and inflammation: A new molecular imaging challenge in the era of personalized medicine

The relationship between cancer and inflammation is one of the most important fields for both clinical and translational research. Despite numerous studies reported interesting and solid data about the prognostic value of the presence of inflammatory infiltrate in cancers, the biological role of inflammation in prostate cancer development is not yet fully clarified. The characterization of molecular pathways that connect altered inflammatory response and prostate cancer progression can provide the scientific rationale for the identification of new prognostic and predictive biomarkers. Specifically, the detection of infiltrating immune cells or related-cytokines by histology and/or by molecular imaging techniques could profoundly change the management of prostate cancer patients. In this context, the anatomic pathology and imaging diagnostic teamwork can provide a valuable support for the validation of new targets for diagnosis and therapy of prostate cancer lesions associated to the inflammatory infiltrate. The aim of this review is to summarize the current literature about the role of molecular imaging technique and anatomic pathology in the study of the mutual interaction occurring between prostate cancer and inflammation. Specifically, we reported the more recent advances in molecular imaging and histological methods for the early detection of prostate lesions associated to the inflammatory infiltrate.

Imaging for the Detection of Locoregional Recurrences in Biochemical Progression After Radical Prostatectomy-A Systematic Review

CONTEXT

Local and regional recurrence after radical prostatectomy (RP) can be treated using salvage radiotherapy (SRT). If the recurrence can be delineated on diagnostic imaging, this could allow for increasingly individualized SRT.

OBJECTIVE

This systematic review aimed at evaluating the evidence regarding the usefulness of positron emission tomography (PET) and magnetic resonance imaging (MRI) in identifying local and regional recurrences, with the aim to further individualize the SRT treatment.

EVIDENCE ACQUISITION

A systematic PubMed/Medline search was conducted in December 2015. Studies included were imaging studies of post-RP patients focusing on local and/or regional recurrence where sensitivity and specificity of MRI or PET were the primary end points. Only studies using biopsy, other histological analysis, and/or treatment follow-up as reference standard were included. Quality Assessment of Diagnostic Accuracy Studies-2 was used to score the study quality. Twenty-five articles were deemed of sufficient quality and included in the review.

EVIDENCE SYNTHESIS

[¹¹C]Acetate had the highest pooled sensitivity (92%), while [¹¹C]choline and [¹⁸F]choline had pooled sensitivities of 71% and 84%, respectively. The PET tracer with highest pooled specificity was [¹¹C]choline (86%). Regarding MRI, MR spectroscopy combined with dynamic contrast enhanced (DCE) MRI showed the highest pooled sensitivity (89%). High pooled sensitivities were also seen using multiparametric MRI (84%), diffusion-weighted MRI combined with T2-weigthed (T2w) imaging (82%), and DCE MRI combined with T2w imaging (82%). These also showed high pooled specificities (85%, 89%, and 92%, respectively).

CONCLUSIONS

Both MRI and PET have adequate sensitivity and specificity for the detection of prostate cancer recurrences post-RP. Multiparametric MRI, using diffusion-weighted and/or DCE imaging, and the choline-labeled tracers showed high pooled sensitivity and specificity, although their ranges were broad.

PATIENT SUMMARY

After reviewing imaging studies of recurrent prostate cancer after prostatectomy, we concluded that choline positron emission tomography and diffusion-weighted magnetic resonance imaging can be proposed as the current standard, with high sensitivity and specificity.

Discrimination of local recurrence after radical prostatectomy: value of diffusion-weighted magnetic resonance imaging

Background

Multiparametric magnetic resonance is the most accurate imaging technique for prostate cancer detection, staging, localization, and aggressiveness evaluation. We assessed accuracy of diffusion-weighted imaging in local recurrence diagnosis after radical prostatectomy.

Materials and methods

A retrospective study was conducted in 118 patients with findings suggestive of local recurrence in dynamic contrast-enhanced-magnetic resonance imaging. Local recurrence was defined clinically as a rising prostate-specific antigen level (biochemical recurrence) without radiographic evidence of distant metastasis over 6 months after surgery. Eighty-four patients (71.2%) had local recurrence (group 1) and 34 (28.8%) showed no recurrence (group 2). The diagnostic accuracy of diffusion-weighted imaging was assessed, and factors associated with local recurrence were evaluated using multivariate logistic regression analysis. Additional accuracy analysis was carried out according to the size of the nodule.

Results

In post-operative findings, group 1 patients had significantly higher serum prostate-specific antigen (P = 0.001), larger enhancing nodules (P = 0.005), and more positive findings in diffusion-weighted imaging (P = 0.001) than group 2 patients. The sensitivity of diffusion-weighted imaging was significantly higher for nodules ≥1 cm than for all nodules (96.6 vs. 80.9%, P = 0.001), whereas the specificities were equivalent (100.0 vs. 97.1, P = 0.529). In multivariate analysis, a positive finding in diffusion-weighted imaging was the independent predictor of local recurrence (P = 0.005), along with pathologic T stage (P = 0.018).

Conclusions

Diffusion-weighted imaging is accurate in distinguishing recurrence from enhancing nodule on dynamic contrast-enhanced-magnetic resonance. Nodules showing decreased diffusion suggest local recurrence, especially if sized ≥1 cm.

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.

PET imaging of recurrent and metastatic prostate cancer with novel tracers

Early detection of recurrent prostate cancer (PCa) is of paramount importance to deliver prompt and accurate therapy reducing the chance of progression to metastatic disease. However, current imaging modalities such as conventional computed tomography, MRI and PET scanning do not provide sufficient sensitivity, especially at lower prostate-specific antigen values. Moreover, biological characterization of PCa has become increasingly important to provide patient-specific therapy and current imaging poorly characterizes disease aggressiveness. The current uprise of novel PET tracers in recurrent and metastatic PCa shows promising, yet variable sensitivities and specificities in detection, indicating the need for further studies. In this review, we highlight current and new PET tracers that have been developed to improve the detection of recurrent and metastatic PCa.

Role of multiparametric MRI in the diagnosis of prostate cancer: update

Prostate cancer is the most common malignancy of the male gender. The role of magnetic resonance imaging has evolved very rapidly over the years to be currently recognized as a fundamental tool in the diagnosis, treatment and follow-up of prostate cancer.

Magnetic resonance imaging for localization of prostate cancer in the setting of biochemical recurrence

The clinical suspicion of local recurrence of prostate cancer after radical treatment is based on the onset of biochemical failure. The use of multiparametric magnetic resonance imaging (MRI) for prostate cancer has increased over recent years, mainly for detection, staging, and active surveillance. However, suspicion of recurrence in the set of biochemical failure is becoming a significant reason for clinicians to request multiparametric MRI. Radiologists should be able to recognize the normal posttreatment MRI findings. Fibrosis and atrophic remnant seminal vesicles (SV) after radical prostatectomy are often found and must be differentiated from local relapse. Moreover, brachytherapy, external beam radiotherapy, and focal therapies tend to diffusely decrease the signal intensity of the peripheral zone on T2-weighted images due to the loss of water content, consequently mimicking tumor and hemorrhage. The combination of T2-weighted images and functional studies like diffusion-weighted imaging and dynamic contrast-enhanced imaging improves the identification of local relapse. Tumor recurrence tends to restrict on diffusion images and avidly enhances after contrast administration. The authors provide a review of the normal findings and the signs of local tumor relapse after radical prostatectomy, external beam radiotherapy, brachytherapy and focal therapies.

Imaging for Prostate Cancer Recurrence

CONTEXT

Correct identification of metastatic sites in recurrent prostate cancer (PCa) is of crucial importance because it leads to further treatment decisions.

OBJECTIVE

To provide an overview on current imaging procedures and their performance in recurrent PCa.

EVIDENCE ACQUISITION

Medline search via PubMed was performed with the keywords imaging, recurrent, and prostate cancer as well as more detailed searches including the keywords bone scan, bone scintigraphy, computed tomography, magnetic resonance imaging, positron emission tomography, PET, choline, FDG, prostate-specific membrane antigen, and PSMA, with emphasis on recent literature from 2010 to the present. Non-English published literature was excluded. Abstracts and full-text articles were reviewed and assessed for relevant content.

EVIDENCE SYNTHESIS

In diagnostic imaging and particularly with newer technologies like positron emission tomography (PET), a profound lack of prospectively designed studies in recurrent PCa has to be noted. In most studies histologic validation has only been performed in a subset of patient cohorts. Heterogeneity of included patient cohorts, lack of standardized assessment, as well as diverging end points, hamper systematic comparison of different image modalities. Thus evidence for currently used imaging in recurrent PCa is only presented descriptively.

CONCLUSIONS

Computed tomography and magnetic resonance imaging (MRI) as well as bone scintigraphy still represent the standard imaging for recurrent PCa; however, particularly for detection of local recurrence, multiparametric MRI is a valuable imaging modality. PET using choline and particularly tracers against prostate-specific membrane antigen might improve visualization of metastatic lesions. These findings need to be validated in prospective trials.

PATIENT SUMMARY

Imaging of recurrent prostate cancer (PCa) is important to guide further treatment. Computed tomography, magnetic resonance imaging, and bone scintigraphy represent the current standard. Positron emission tomography, especially with cancer-specific tracers, might improve imaging of recurrent PCa in the future.

Evaluating the Role of mpMRI in Prostate Cancer Assessment

Prostate cancer is the most common malignancy among American men. The role of multi-parametric MRI has recently gained more importance in detection of prostate cancer, its targeted biopsy, and focal therapy guidance. In this review, uses of multi-parametric MRI in prostate cancer assessment and treatment are discussed.

Spanish Society of Radiation Oncology clinical guidelines for stereotactic body radiation therapy in lymph node oligometastases

Data in the literature support the existence of a state of limited metastases or oligometastases. Favorable outcomes have been observed in selected patients with such oligometastases that are treated with local ablative therapies, which include surgical extirpation, stereotactic body radiation therapy (SBRT), and radiofrequency ablation. The role of SBRT in the setting of lymph node oligometastases is still emerging but the early results for local control are promising. However, the biggest challenge is to identify patients who will benefit from treatment of their oligometastatic disease with local aggressive therapy. Patients are initially categorized based upon examination of the initial biopsy, location, stage, and previous treatments received. Appropriate patient management with SBRT requires an understanding of several clinicopathological features that help to identify several subsets of patients with more responsive tumors and a good tolerance to SBRT. In an effort to incorporate the most recent evidence, here the Spanish Society of Radiation Oncology presents guidelines for using SBRT in lymph node oligometastases.

Multiparametric magnetic resonance imaging-transrectal ultrasound fusion-assisted biopsy for the diagnosis of local recurrence after radical prostatectomy

OBJECTIVE

Approximately 15% of patients who undergo radical prostatectomy (RP) for prostate cancer develop local recurrence, which is heralded by a rise in serum prostate-specific antigen (PSA) levels. Early detection and treatment of recurrence improves the outcome of salvage treatment. We investigated the ability of multiparametric magnetic resonance imaging (mpMRI)-transrectal ultrasound (TRUS) fusion-guided biopsy (FGB) combined with "cognitive biopsy" to confirm local recurrence of prostate cancer after RP.

MATERIALS AND METHODS

In this retrospective study conducted between January 2010 and December 2014, patients with rising PSA levels after RP who had no known evidence of distant metastases underwent mpMRI including T2-weighted (T2W) imaging, diffusion-weighted imaging, dynamic contrast-enhanced (DCE) MRI at 3 Tesla, and subsequent MRI-ultrasound fusion biopsy with cognitive assistance. The detection rate of locally recurrent disease was determined.

RESULTS

A total of 10 patients (mean age = 67y, mean PSA level = 3.44ng/ml) met the inclusion criteria. Of the 10 patients, all had positive findings suspicious for local recurrence on mpMRI per entrance criterion. The most important features on mpMRI were early enhancement on DCE MR images and hypointensity on T2W images. The average lesion diameter on mpMRI was 1.12cm (range: 0.40-2.20cm). All suspicious lesions (16/16, 100%) were positive on T2W MR images, 14 (89%) showed positive features on apparent diffusion coefficient maps of diffusion-weighted images, and 16 (100%) were positive on DCE MR images. MRI-TRUS FGBs were positive in 10/16 lesions (62.5%) and 8/10 (80%) patients.

CONCLUSION

MRI-TRUS FGB with cognitive assistance is able to detect and diagnose locally recurrent lesions after RP, even at low PSA levels. This may facilitate early detection of recurrent disease and improve salvage treatment outcomes.

Current Use of Imaging after Primary Treatment of Prostate Cancer

PURPOSE

Data are limited on imaging after primary treatment of localized prostate cancer.

MATERIALS AND METHODS

We identified 8,435 men newly diagnosed with nonmetastatic prostate cancer in 1995 to 2012 who were enrolled in CaPSURE™. Patients were followed after primary treatment with radical prostatectomy, cryosurgery, brachytherapy, external beam radiation therapy or androgen deprivation therapy. We assessed the use of bone scan, computerized tomography and magnetic resonance imaging after primary treatment. Factors associated with posttreatment outcomes (number of imaging tests, and time to first imaging and salvage treatment) were evaluated with multivariate Poisson regression and Cox proportional hazards regression.

RESULTS

The incidence of posttreatment bone scan, computerized tomography and magnetic resonance imaging was 20% or less. Last posttreatment log(prostate specific antigen) was associated with multiple posttreatment imaging. Management by radical prostatectomy, cryosurgery, external beam radiation therapy or brachytherapy vs androgen deprivation therapy was associated with a lower likelihood of posttreatment imaging. Of patients who were imaged after treatment 25% with radical prostatectomy and 9% with radiation underwent imaging before prostate specific antigen failure. The 5-year salvage treatment-free survival rate was 81%. Positive findings on posttreatment imaging were associated with a higher risk of salvage treatment.

CONCLUSIONS

Patients treated with androgen deprivation therapy for localized disease were most likely to be imaged, primarily by bone scan. Men treated with other therapies were less likely to be imaged and tended to undergo computerized tomography. Imaging may add value to posttreatment prostate specific antigen monitoring to identify disease recurrence and progression. Further studies are needed to establish guidelines for the optimal frequency and imaging type to monitor the treatment response.

Imaging biomarkers in prostate cancer: role of PET/CT and MRI

Prostate-specific antigen (PSA) is currently the most widely used biomarker of prostate cancer (PCa). PSA suggests the presence of primary tumour and disease relapse after treatment, but it is not able to provide a clear distinction between locoregional and distant disease. Molecular and functional imaging, that are able to provide a detailed and comprehensive overview of PCa extension, are more reliable tools for primary tumour detection and disease extension assessment both in staging and restaging. In the present review we evaluate the role of PET/CT and MRI in the diagnosis, staging and restaging of PCa, and the use of these imaging modalities in prognosis, treatment planning and response assessment. Innovative imaging strategies including new radiotracers and hybrid scanners such as PET/MRI are also discussed.