MRI Of The Prostate: A Practical Approach Download Pdf

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Mozell Gentges

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Jul 4, 2024, 6:39:16 AM7/4/24
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The necessity for random sampling has been challenged by new developments in radiology, with multiparametric MRI evolving as a novel technique of prostate imaging that can detect significant tumors radiologically. However, recent studies comparing MRI-guided biopsies and additional random sampling still demonstrate the value of using both approaches to detect this heterogeneously distributed and differentiated tumor [7].

The multifocality of prostate cancer has long been described and also constitutes a problem for diagnosis and therapy planning [8,9]. Acknowledging this issue has become more relevant as novel approaches of focal therapy arise [10]. In radical prostatectomy specimens, on average, 2.5 tumor foci can be distinguished, if carefully analyzed [11,12]. The common multifocality and spatial heterogeneity of cancer distribution implies that pathologists cannot reliably ascertain if several positive tumor cores belong to the same tumor focus and may thus be lumped into a single diagnosis. Hence, common practice in most prostate cancer centers is still the individual reporting of each positive biopsy core. This may change in the future, if detailed imaging or molecular information can be reliably integrated in the diagnostic workup.

The basic histological categories of adenocarcinoma of the prostate as currently defined by the WHO are surprisingly homogenous (briefly reviewed [14]), with the vast majority (>95%) of tumors being classified as acinar adenocarcinoma [15]. As acinar adenocarcinoma of the prostate displays a wide spectrum of morphological patterns (Fig. 1), establishing a system to categorize it further into biologically and prognostically meaningful subgroups, i.e., to establish a grading system, has taken a long time to develop. Broders [16 ]is often cited as the grandfather of urogenital tumor grading, even though he did not write specifically about prostate cancer. However, his approach to generally classify tumors by the extent of undifferentiated cells deserves credit.

While localised prostate cancer can be cured by local treatment, 'high-risk' prostate cancer often progresses to castration resistant disease and remains incurable with a dismal prognosis. In recent years, technical advances and development of novel methodologies have largely contributed to a better understanding of underlying molecular mechanisms that promote tumour growth and progression. Consecutively, novel therapeutic strategies for treatment of prostate cancer have emerged during the last decade, calling for the identification of predictive biomarkers. The concept of personalised medicine is to tailor treatment according to the specific tumour profile of an individual patient. Moreover, acquired molecular changes during tumour evolution and in response to therapy selection pressure require adapted predictive marker testing at different time points during the disease. In this setting, the pathologist plays a critical role in patient management and treatment selection. In this review, we provide a comprehensive overview of the current knowledge of molecular aspects of prostate cancer and their potential utility in the context of different therapeutic approaches. Furthermore, we discuss methods for molecular marker testing in routine clinical practice, with a focus on castration resistant prostate cancer.

Active surveillance (AS) is a management option for men diagnosed with lower risk prostate cancer. There is wide variation in all aspects of AS internationally, from patient selection to investigations and follow-up intervals, and a lack of clear evidence on the optimal approach to AS. This study aimed to provide guidance for clinicians from an international panel of prostate cancer experts.

A modified Delphi approach was undertaken, utilising two rounds of online questionnaires followed by a face-to-face workshop. Participants indicated their level of agreement with statements relating to patient selection for AS via online questionnaires on a 7-point Likert scale. Factors not achieving agreement were iteratively developed between the two rounds of questionnaires. Draft statements were presented at the face-to-face workshop for discussion and consensus building.

Given the challenges in accurately diagnosing and classifying prostate cancer and the range of AS strategies that have been trialled to date, the wide variation in AS that currently exists in clinical practice is probably not surprising. Numerous studies have shown significant variation in all aspects of AS, including patient selection, follow-up protocols, and criteria for switching to radical treatments. This variation in AS practice has been shown to exist between institutions, regionally within countries, and in national and international guidelines [16,17,18,19]. Whilst survey data shows that the majority of clinicians perceive AS to be effective [20], the optimal approach to selecting patients for AS is still unknown. This modified Delphi study aimed to develop consensus on practical guidance for clinicians in the appropriate selection of men with lower risk prostate cancer to recommend active surveillance.

This modified Delphi study sought to address current issues surrounding the consistency and quality of care for men with prostate cancer who could potentially benefit from active surveillance as a treatment modality. The panel considered a range of issues relating to AS, including underlying principles of treatment, diagnostic information, and risk assessment. The agreed criteria outline a relatively flexible approach to offering AS, reflecting the current uncertainties and evolving evidence around the optimal use and delivery of AS.

There were a number of key principles on which the participants held clear agreement. The panel agreed that a patient with prostate cancer should be in a reasonable state of health in order to benefit from active surveillance, and that their life expectancy, medical co-morbidities, suitability for radical treatment, and treatment preferences should all be taken into consideration for management decision-making. In the context of the known limitations of the current prostate cancer diagnostic tests, with the potential for over-diagnosis and misclassification of prostate cancer, a rigorous approach to AS is critical to avoid over-treatment and the associated adverse effects for men. The panel also felt that an optimal AS follow-up protocol would be able to accurately identify disease progression to inform decisions about switching to radical treatment.

The number of positive cores and positive core length can be influenced by the location of the biopsy sampling and the total number of cores taken, and the relative importance of these factors was not agreed upon by the panel. Most prostate cancer guidelines do not include the number of positive cores or the percentage of cancer per core in prostate cancer risk definitions, although many individual centres still include these measures in their AS eligibility criteria [17, 18]. The panel generally felt that Transrectal Ultrasound-guided biopsy (TRUS) alone was not sufficiently accurate to be used as the basis for histopathological assessment of a prostate cancer, and ideally a Transperineal (TP) biopsy approach was followed. This reflects the general trend towards increasing use of TP biopsy due to its lower adverse effect profile and ability to access all areas of the prostate [24]. The need for a confirmatory biopsy in tertiary centre referrals was also debated, with no clear opinion reached; however the importance of concordance between mpMRI and biopsy findings was felt to be vital in reassuring the clinicians and the patient that an accurate diagnosis has been made.

This modified Delphi study was conducted in a methodologically rigorous manner. A diverse panel of international prostate cancer experts was assembled, with an optimal number of participants who engaged throughout the whole process. Agreement was achieved on the consensus statements through robust discussion and iterative work over two rounds of questionnaires, followed by a face-to-face workshop to refine the criteria [25]. The panel has developed a set of practical recommendations that take into consideration the latest evidence in the field. The role of certain tests, including number of positive cores and Free:Total PSA ratio, in patient selection for AS was not agreed by the panel, although this could be considered to be a reflection of the current state of the evidence in these areas [15].

This book is a basic, practical guide to performing and interpreting state-of-the-art prostate MRI, utilizing the latest guidelines in the field. Prostate MRI has become one of the fastest growing examinations in the radiology practice, and this demand has continuously increased within the past decade. Since it is relatively new, MRI of the prostate is predominantly being performed at academic institutions, however there is a growing demand within the lower-tier health care institutions to offer this examination to their patients. This is an ideal guide for radiologists who want to enhance or initiate prostate MRI service for their referring clinicians and as a manual for technologists and those who are in training.

Men with mild symptoms of BPH who do not find them bothersome often choose this approach. Watchful waiting means getting annual checkups. Treatment is started only if symptoms become too much of a problem.

Sandra M. Gaston, Gary P. Kearney, William E. Grizzle; Abstract A47: Prostate biopsy tissue print technologies: A practical and innovative approach to overcoming racial disparities in the datasets used for prostate cancer biomarker development. Cancer Epidemiol Biomarkers Prev 1 September 2011; 20 (10_Supplement): A47. -9965.DISP-11-A47

We have formed a collaboration in which tissue print technologies are used to support a systematic comparison of molecular biomarker patterns in prostate biopsies obtained from African American and European American patients. Our data analysis plan includes an evaluation of marker associations with both self-identified ancestry and with genetic lineage as defined by ancestry informative markers. This approach has been particularly interesting in the evaluation of DNA methylation markers, where it has been demonstrated that the extent of cancer-associated hypermethylation depends in part on the DNA sequence of the marker allele. More generally, because the use of biopsy samples allows us to obtain a more representative sample of the African Americans and European American patient populations, we can improve the pre-clinical assessment of potential strengths and weaknesses of specific biomarker tests as tools for guiding patient care

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