[Health-economic evaluation of magnetic resonance imaging before biopsy for diagnosis of prostate cancer]

Evaluation of Prostate HistoScanning as a Method for Targeted Biopsy in Routine Practice

BACKGROUND

Prostate HistoScanning (PHS) is a tissue characterization system used to enhance prostate cancer (PCa) detection via transrectal ultrasound imaging.

OBJECTIVE

To assess the impact of supplementing systematic transrectal biopsy with up to three PHS true targeting (TT) guided biopsies on the PCa detection rate and preclinical patient assessment.

DESIGN, SETTING, AND PARTICIPANTS

This was a prospective study involving a cohort of 611 consecutive patients referred for transrectal prostate biopsy following suspicion of PCa. PHS-TT guided cores were obtained from up to three PHS lesions of ≥0.5cm³ per prostate and only one core per single PHS lesion. Histological outcomes from a systematic extended 12-core biopsy (Bx) scheme and additional PHS-TT guided cores were compared.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Comparison of PHS results and histopathology was performed per sextant. The χ² and Mann-Whitney test were used to assess differences. Statistical significance was set at p<0.05.

RESULTS AND LIMITATIONS

PHS showed lesions of ≥0.5cm³ in 312 out of the 611 patients recruited. In this group, Bx detected PCa in 59% (185/312) and PHS-TT in 87% (270/312; p<0.001). The detection rate was 25% (944/3744 cores) for Bx and 68% (387/573 cores) for PHS-TT (p<0.001). Preclinical assessment was significantly better when using PHS-TT: Bx found 18.6% (58/312) and 8.3% (26/312), while PHS-TT found 42.3% (132/312) and 20.8% (65/312) of Gleason 7 and 8 cases, respectively (p<0.001). PHS-TT attributed Gleason score 6 to fewer patients (23.4%, 73/312) than Bx did (32.4%, 101/312; p=0.0021).

CONCLUSIONS

Patients with a suspicion of PCa may benefit from addition of a few PHS-TT cores to the standard Bx workflow.

PATIENT SUMMARY

Targeted biopsies of the prostate are proving to be equivalent to or better than standard systematic random sampling in many studies. Our study results support supplementing the standard schematic transrectal ultrasound-guided biopsy with a few guided cores harvested using the ultrasound-based prostate HistoScanning true targeting approach in cases for which multiparametric magnetic resonance imaging is not available.

[Health technology assessment (HTA). Developments in healthcare and potential for radiology]

CLINICAL/METHODICAL ISSUE

Cost-intensive measures and procedures, such as also employed in radiology, have far-reaching economic implications in respect to increasing expenditure with limited resources.

STANDARD RADIOLOGICAL METHODS

Health technology assessment (HTA) describes the systematic evaluation of medical procedures and technologies which in recent years has been introduced by many countries into healthcare politics.

ASSESSMENT

In many cases HTA analyses can be directly implemented into practice as shown by the examples given in this article; however, in the current form of HTA the practical implementation for radiology often presents the problem that the cost-benefit ratio does not yet have a comprehensive view in the HTA report but is limited to a subsection, e.g. current costs versus sensitivity of a method. Since its inception radiology has had a high power of innovation and new developments will also substantially determine the future years. These procedures must not only be evaluated with respect to feasibility but also in the sense of the HTA in the total concept.

PRACTICAL RECOMMENDATIONS

In radiology there are also a large number of possibilities for radiologists not only as passive consumers of HTA reports but also to become active participants in this process, an opportunity which should be taken advantage of.

Limited evidence for the use of imaging to detect prostate cancer: a systematic review

OBJECTIVE

To assess the diagnostic accuracy of imaging technologies for detecting prostate cancer in patients with elevated PSA-values or suspected findings on clinical examination.

METHODS

The databases Medline, EMBASE, Cochrane, CRD HTA/DARE/NHS EED and EconLit were searched until June 2013. Pre-determined inclusion criteria were used to select full text articles. Risk of bias in individual studies was rated according to QUADAS or AMSTAR. Abstracts and full text articles were assessed independently by two reviewers. The performance of diagnostic imaging was compared with systematic biopsies (reference standard) and sensitivity and specificity were calculated.

RESULTS

The literature search yielded 5141 abstracts, which were reviewed by two independent reviewers. Of these 4852 were excluded since they did not meet the inclusion criteria. 288 articles were reviewed in full text for quality assessment. Six studies, three using MRI and three using transrectal ultrasound were included. All were rated as high risk of bias. Relevant studies on PET/CT were not identified.

CONCLUSION

Despite clinical use, there is insufficient evidence regarding the accuracy of imaging technologies for detecting cancer in patients with suspected prostate cancer using TRUS guided systematic biopsies as reference standard.