Freehand Transperineal Prostate Biopsy with Three-Dimensional Ultrasound Organ-Based Tracking

3D ultrasound guidance for radiofrequency ablation in an anthropomorphic thyroid nodule phantom

BACKGROUND

The use of two-dimensional (2D) ultrasound for guiding radiofrequency ablation (RFA) of benign thyroid nodules presents limitations, including the inability to monitor the entire treatment volume and operator dependency in electrode positioning. We compared three-dimensional (3D)-guided RFA using a matrix ultrasound transducer with conventional 2D-ultrasound guidance in an anthropomorphic thyroid nodule phantom incorporated additionally with temperature-sensitive albumin.

METHODS

Twenty-four phantoms with 48 nodules were constructed and ablated by an experienced radiologist using either 2D- or 3D-ultrasound guidance. Postablation T2-weighted magnetic resonance imaging scans were acquired to determine the final ablation temperature distribution in the phantoms. These were used to analyze ablation parameters, such as the nodule ablation percentage. Further, additional procedure parameters, such as dominant/non-dominant hand use, were recorded.

RESULTS

Nonsignificant trends towards lower ablated volumes for both within (74.4 ± 9.1% (median ± interquartile range) versus 78.8 ± 11.8%) and outside of the nodule (0.35 ± 0.18 mL versus 0.45 ± 0.46 mL), along with lower variances in performance, were noted for the 3D-guided ablation. For the total ablation percentage, 2D-guided dominant hand ablation performed better than 2D-guided non-dominant hand ablation (81.0% versus 73.2%, p = 0.045), while there was no significant effect in the hand comparison for 3D-guided ablation.

CONCLUSION

3D-ultrasound-guided RFA showed no significantly different results compared to 2D guidance, while 3D ultrasound showed a reduced variance in RFA. A significant reduction in operator-ablating hand dependence was observed when using 3D guidance. Further research into the use of 3D ultrasound for RFA is warranted.

RELEVANCE STATEMENT

Using 3D ultrasound for thyroid nodule RFA could improve the clinical outcome. A platform that creates 3D data could be used for thyroid diagnosis, therapy planning, and navigational tools.

KEY POINTS

Twenty-four in-house-developed thyroid nodule phantoms with 48 nodules were constructed. RFA was performed under 2D- or 3D-ultrasound guidance. 3D- and 2D ultrasound-guided RFAs showed comparable performance. Real-time dual-plane imaging may offer an improved overview of the ablation zone and aid electrode positioning. Dominant and non-dominant hand 3D-ultrasound-guided RFA outcomes were comparable.

Pooled outcomes of performing freehand transperineal prostate biopsy with the PrecisionPoint Transperineal Access System

Objectives

To report the results of a pooled analysis evaluating the cancer detection rates, complications, and tolerability of prostate biopsies performed using the PrecisionPoint Transperineal Access System.

Patients and Methods

The medical literature was reviewed to identify studies published prior to 1 October 2021 evaluating the PrecisionPoint device for performance of transperineal prostate biopsy. Pooled analyses were performed to assess overall and clinically significant cancer detection rates. Additionally, data on complications as well as patient tolerability of the procedure when performed under local anaesthesia were extracted.

Results

Transperineal biopsy with the PrecisionPoint Transperineal Access System achieved overall and clinically significant cancer detection rates of 67.9% and 42.6%, respectively. Among patients with Prostate Imaging Reporting and Data System 3, 4, and 5 lesions on prostate magnetic resonance imaging, clinically significant disease was found in 31.7%, 55.7%, and 71.8% of patients, respectively. Complications were rare, with sepsis reported in 4 (0.1%) of 3411 procedures despite frequent omission of antibiotic prophylaxis. Patients reported acceptable tolerability of the procedure when performed under local anaesthesia.

Conclusions

Within the available medical literature, there is uniform evidence supporting the use of the PrecisionPoint Transperineal Access System for performing prostate biopsy procedures. The reported cancer detection and infectious complication rates with this device are in line with other methods for performing transperineal prostate biopsy. A unique aspect of the PrecisionPoint device is its ability to facilitate performing transperineal prostate biopsy under local anaesthesia. This factor will likely lead to increased adoption of the beneficial transperineal approach to prostate biopsy.

Impact of prostate biopsy technique on outcomes of the precision prostatectomy procedure

Objective

To assess the impact of iterative changes in preoperative and postoperative biopsy techniques on the outcomes of men undergoing the precision prostatectomy procedure. Precision prostatectomy is a novel surgical treatment for prostate cancer that aims to maximally preserve erectogenic nerves via partial preservation of the prostate capsule.

Design

Retrospective.

Setting

Single tertiary care center.

Participants

This study included 120 patients who consented to undergo prostate cancer treatment with the precision prostatectomy procedure. Patients were originally enrolled in one of two separate prospective protocols studying precision prostatectomy.

Interventions

Preoperatively, 60 patients were screened with transrectal (TR) biopsy and 60 were screened by transperineal (TP) biopsy. Ultimately, 117 patients underwent precision prostatectomy. Of the 43 postoperative biopsies, 19 were TR; 17 were TP with ultrasound; and 7 were TP with microultrasound (mUS).

Main outcome measures

Preoperatively, we evaluated whether the transition to TP biopsy was associated with differences in postoperative treatment failure defined as a neoplasm-positive postoperative biopsy. Postoperative biopsies were compared with respect to their ability to sample the remnant tissue, specifically percentage of cores positive for prostate tissue.

Results

Preoperatively, 9/60 (15%) positive postoperative biopsies occurred in the TR group and 6/60 (10%) in the TP group; Kaplan-Meier survival estimates did not differ between groups (p=0.69 by log rank). Postoperatively, the numbers of cores positive for prostate tissue were 99/160 (62%), 63/107 (59%), and 36/39 (92%) in the TR biopsy, TP with ultrasound, and TP with mUS groups, respectively; this difference was statistically significant versus the rate in the TR and standard TP groups (p=0.0003 and 0.0002).

Conclusion

We found no significant improvement in patient screening, preoperatively—though limited by small sample size and relatively short follow-up. The incorporation of high-frequency mUS for postoperative biopsies improved the ability to sample the remnant tissue with a higher efficiency.