Incidental findings in and around the prostate on prostate MRI: a pictorial review

Prostatic Utricle Cysts as a Potential Pitfall in PSMA PET/CT Interpretation

ABSTRACT

A 60-year-old man with T2aN0M0 prostate cancer underwent intensity-modulated radiotherapy targeting the prostate and seminal vesicles. Experiencing biochemical recurrence after 6 years, 68 Ga-PSMA-11 PET/CT revealed focal radioactivity in the posterior midline of the prostate, identified as a prostatic utricle cyst on subsequent MRI. Similar findings appeared in a previous 18 F-piflufolastat PET/CT, with negative biopsy results. The patient then received intensity-modulated radiotherapy directed to 2 PSMA-avid pelvic nodes and leuprolide acetate, achieving an undetectable PSA in 4 months. This case highlights a potential pitfall in PSMA PET interpretation associated with prostatic utricle cysts.

Quantification and significance of extraprostatic findings on prostate MRI: a retrospective analysis and three-tier classification

OBJECTIVES

To quantify extraprostatic findings (EPFs) on prostate MRI, estimate the proportion of reported and unreported EPFs, assess their clinical importance, and propose standardized reporting of EPFs.

MATERIALS AND METHODS

Prostate 3-T MRI studies, reports, and clinical data from 623 patients (age 67.9 ± 8.2 years) were retrospectively analyzed and re-evaluated for the presence of EPFs and their clinical significance: E1-no finding or findings that have no clinical significance; E2-potentially significant findings; and E3-significant findings.

RESULTS

Secondary reading identified 1236 EPFs in 593 patients (1.98 ± 1.13 EPFs per patient, no EPFs in 30 patients), from which 468 (37.8%) were mentioned in the original report. The most common findings included diverticulosis (44% of patients), hydrocele (34%), inguinal fat hernia (16%), and bladder wall trabecular hypertrophy (15%). There were 80 (6.5%) E2 EPFs and 30 (2.4%) E3 EPFs. From E3 EPFs, 10 (33%) were not originally reported. A workup was suggested in 35 (52%) of the 67 originally reported E2 and E3 findings with follow-up and performed in 20 (30%). Fourteen (21%) EPFs in 11 patients influenced their management. Four experienced radiologists originally reported 1.8 to 2.5 findings per patient (p < 0.0001).

CONCLUSIONS

EPFs on prostate MRI are frequent, but only 2.4% are clinically significant (E3), and 33% of these are not reported. Only 30% of E2 and E3 findings are further explored, and 21% influence patient management. We suggest that an "E" category should be attached to the PI-RADS system to identify the presence of EPFs that require further workup.

CRITICAL RELEVANCE STATEMENT

Extraprostatic findings on prostate MRI are frequent, but only 2.4% are clinically significant (E3), and 33% of these are not reported. We advocate standardized reporting of extraprostatic findings indicating their clinical significance.

KEY POINTS

• Extraprostatic findings on prostate MRI are frequent with an average of two findings per patient. • 2.4% of extraprostatic findings are significant, and 33% of these are not reported. • There is a significant variability among experienced radiologists in reporting extraprostatic findings.

Extraprostatic incidental findings on prostate mpMRI: A pictorial review from the ESUR junior network

The role of multiparametric MRI (mpMRI) in prostate cancer setting is increasingly consolidated and, as a result, its usage in clinical practice is in exponential growth. However, beyond the prostate gland, several key structures are included in the field of view of mpMRI scans. Consequently, various extra-prostatic incidental findings (IFs) belonging to different anatomical systems can be accidentally recognized. Therefore, it is mandatory for a radiologist to be familiar with the wide range of pathologies potentially encountered, to guide management and avoid patient anxiety and costs due to additional work-up prompted by clinically insignificant extra-prostatic findings. With this pictorial review, we aim to illustrate a wide range of IFs that can be detected when performing mpMRI of the prostate, focusing on their imaging characteristics, differential diagnosis, and clinical relevance. Additionally, we propose the CheckDEEP, the Checklist for DEtection of ExtraProstatic findings, to be used for a thorough evaluation of target areas within each anatomical system.

Integration between Novel Imaging Technologies and Modern Radiotherapy Techniques: How the Eye Drove the Chisel

INTRODUCTION

Targeted dose-escalation and reduction of dose to adjacent organs at risk have been the main goal of radiotherapy in the last decade. Prostate cancer benefited the most from this process. In recent years, the development of Intensity Modulated Radiation Therapy (IMRT) and Stereotactic Body Radiotherapy (SBRT) radically changed clinical practice, also thanks to the availability of modern imaging techniques. The aim of this paper is to explore the relationship between diagnostic imaging and prostate cancer radiotherapy techniques.

MATERIALS AND METHODS

Aiming to provide an overview of the integration between modern imaging and radiotherapy techniques, we performed a non-systematic search of papers exploring the predictive value of imaging before treatment, the role of radiomics in predicting treatment outcomes, implementation of novel imaging in RT planning and influence of imaging integration on use of RT in current clinical practice. Three independent authors (GF, IM and ID) performed an independent review focusing on these issues. Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used, and grey literature was searched for further papers of interest. The final choice of papers included was discussed between all co-authors.

RESULTS

This paper contains a narrative report and a critical discussion of the role of new modern techniques in predicting outcomes before treatment, in radiotherapy planning and in the integration with systemic therapy in the management of prostate cancer. Also, the role of radiomics in a tailored treatment approach is explored.

CONCLUSIONS

Integration between diagnostic imaging and radiotherapy is of great importance for the modern treatment of prostate cancer. Future clinical trials should be aimed at exploring the real clinical benefit of complex workflows in clinical practice.

Incidental findings on prostate MRI: a close look at the field of view in this anatomical region

Magnetic resonance imaging (MRI) has been widely used as an advanced imaging modality to detect prostate cancer and indicate suspicious areas to guide biopsy procedures. The increasing number of prostate examinations with MRI has provided an opportunity to detect incidental lesions, and some might be very significant to elucidate patient symptoms or occult neoplastic process in the early stages. These incidental lesions might be located in the prostate gland, adjacent tissues, or organs around the prostate gland or out of the genitourinary system. The field of view of prostate MRI includes not only the prostate gland but also other critical pelvic organs in this specific anatomical region. Some of these incidental lesions might cause the same symptoms as prostate cancer and might explain the symptoms of the patient, and some might indicate early cancer stages located outside the prostate. Reporting these lesions might be life-saving by initiating early disease treatment. Awareness of the predicted locations of congenital anomalies would also be beneficial for the radiologists to mention these incidental findings.

Cowper's gland hyperplasia: A potential pitfall at MRI of the prostate

MRI features are presented in a multicenter retrospective series of five patients with a unilateral masslike lesion seen in the genitourinary diaphragm at MRI performed for known or suspected prostate cancer. In all cases, the lesion appeared as an encapsulated 1.3 to 3.0 cm mass of heterogeneous low or intermediate T2 signal intensity in the genitourinary diaphragm, and targeted biopsy demonstrated benign Cowper's gland tissue. This entity is a potential imaging pitfall that could result in a diagnosis of an exophytic nodule of benign prostatic hyperplasia or local spread of prostate cancer. We present these cases to facilitate correct identification of Cowper's gland hyperplasia as an occasional finding at MRI of the prostate.