The Role of Multi-Parametric MRI and Fusion Biopsy for the Diagnosis of Prostate Cancer – A Systematic Review of Current Literature

Abstract

Introduction

The use of mutiparametric MRI (MpMRI) guided fusion biopsy is becoming an increasingly popular investigation in an aid to increase diagnostic yield in those suspected of having prostate cancer (PCa). Before adopting this technology, it is necessary to confirm the accuracy, so that PCa can be reliably diagnosed with characterisation.

Materials and Methods

This chapter analysed the evidences, which varied from well-designed randomised controlled trials to case series to detect the accuracy of MpMRI compared with biopsy/ histology.

Results

MpMRI incorporating T2 and diffusion weighted imaging only detects tumours in around 92% cases. When dynamic contrast enhancement is added, cancer diagnosis is significantly improved. Fusion biopsy increases the detection of high-risk PCa by 32% over conventional biopsy alone.

Conclusion

This review also revealed that fusion biopsy did not increase cancer detection rate but combined biopsy (Systematic and fusion) provide the highest detection rate for the diagnosis of PCa.

Appendices

Appendix 1: ‘Critical Appraisal Skills Programme’ (CASP) Appraisal Tools

11 questions to help you make sense of case control study -.

How to use this appraisal tool -Three broad issues need to be considered when appraising a case control study:

● Are the results of the trial valid? ● What are the results ● Will the results help locally?

(Section A) (Section B) (Section C) The 11 questions on the following pages are designed to help you think about these issues systematically.The first two questions are screening questions and can be answered quickly. If the answer to both is “yes”, it is worth proceeding with the remaining questions. There is some degree of overlap between the questions, you are asked to record a “yes”, “no” or “can’t tell” to most of the questions. A number of italicised prompts are given after each question. These are designed to remind you why the question is important. Record your reasons for your answers in the spaces provided.

(A) Are the results of the study valid?

Screening Questions

• 1. Did the study address a clearly focused issue? ⧠Yes ⧠Can’t tell ⧠No

HINT: A question can be focused in terms of The population studied, The risk factors studied, Whether the study tried to detect a beneficial or harmful effect?

• 2. Did the authors use an appropriate method to answer their question?

HINT: Consider ● Is a case control study an appropriate way of answering the question under the circumstances? (Is the outcome rare or harmful) ● Did it address the study question? ⧠Yes ⧠Can’t tell ⧠No.Is it worth continuing?

Detailed questions

• 3. Were the cases recruited in an acceptable way?

HINT: We are looking for selection bias, which might compromise validity of the findings

Are the cases defined precisely? Were the cases representative of a defined population? (Geographically and/or temporally?) Was there an established reliable system for selecting all the cases -Are they incident or prevalent?

Is there something special about the cases?

Is the time frame of the study relevant to disease/exposure? Was there a sufficient number of cases selected?Was there a power calculation?

• 4. Were the controls selected in an acceptable way?

HINT: We are looking for selection bias which might compromise The generalisibilty of the findings.Were the controls representative of defined population (geographically and/or temporally). Was there something special about the controls? Was the non-response high? Could non-respondents be different in any way? Are they matched, population based or randomly selected? Was there a sufficient number of controls selected?

• 5. Was the exposure accurately measured to ⧠Yes minimise bias?

HINT: We are looking for measurement, recall or classification bias

Was the exposure clearly defined and accurately measured? Did the authors use subjective or objective measurements? Do the measures truly reflect what they are supposed to measure? (Have they been validated?) Were the measurement methods similar in the cases and controls? Did the study incorporate blinding where feasible? Is the temporal relation correct? (Does the exposure of interest precede the outcome?)

• 6. (a) What confounding factors have the List: authors accounted for? HINT: List the ones you think might be important, that The author missed. Genetic, Environmental, Socio-economic.

• (b) Have the authors taken account of the potential confounding factors in the design and/or in their analysis? HINT: Look for

• Restriction in design, and techniques e.g. modelling stratified-, regression-, or sensitivity analysis to correct, control or adjust for confounding factors

• 7. What are the results of this study? HINT: Consider -What are the bottom line results?Is the analysis appropriate to the design? How strong is the association between exposure and outcome (look at the odds ratio)? Are the results adjusted for confounding, and might confounding still explain the association? Has adjustment made a big difference to the OR?

  (B) What are the results?

• 8. How precise are the results? How precise is the estimate of risk?

HINT: Consider -Size of the P-value, Size of the confidence intervals, Have the authors considered all the important variables? How was the effect of subjects refusing to participate evaluated?

• 9. Do you believe the results? HINT: Consider -Big effect is hard to ignore! Can it be due to chance, bias or confounding? Are the design and methods of this study sufficiently flawed to make the results unreliable? Consider Bradford Hills criteria (e.g. time sequence, dose-response gradient, strength, biological plausibility)

  (C) Will the results help locally?

• 10. Can the results be applied to the local population? HINT: Consider whether -The subjects covered in the study could be sufficiently different from your population to cause concern. Your local setting is likely to differ much from that of the study. Can you quantify the local benefits and harms?

• 11. Do the results of this study fit with other available evidence? HINT: Consider all the available evidence from RCT’s, systematic reviews, cohort studies and case-control studies as well for consistency.

One observational study rarely provides sufficiently robust evidence to recommend changes to clinical practice or within health policy decision-making. However, for certain questions observational studies provide the only evidence. Recommendations from observational studies are always stronger when supported by other evidence.

Appendix 2 – Grading of Recommendations

A new system for grading recommendations in evidence based guidelines Harbour, R. and Miller, J. 2001. The Scottish Intercollegiate Guidelines Network Grading Review Group. Scottish Intercollegiate Guidelines Network, Royal College of Physicians of Edinburgh, Edinburgh EH2 1JQ

Levels of evidence-

• 1++ High quality meta-analyses, systematic reviews of RCTs, or RCTs with a very low risk of bias

• 1+ Well conducted meta-analyses, systematic reviews of RCTs, or RCTs with a low risk of bias

• 1+ Meta-analyses, systematic reviews or RCTs, or RCTs with a high risk of bias

• 2++ High quality systematic reviews of case-control or cohort studies or High quality case- control or cohort studies with a very low risk of confounding, bias, or chance and a high probability that the relationship is causal

• 2+ Well conducted case-control or cohort studies with a low risk of confounding, bias, or chance and a moderate probability that the relationship is causal

• 2+ Case-control or cohort studies with a high risk of confounding, bias, or chance and a significant risk that the relationship is not causal

• 3+ Non-analytic studies, e.g. case reports, case series

• 4+ Expert opinions.