Optimal prostate biopsy regimen

The 3DBiopsy Prostate Biopsy System: Preclinical Investigation of a Needle, Actuator, and Specimen Collection Device Allowing Sampling of Individualized Prostate Lengths Between 20 and 60 mm

OBJECTIVE

To increase the likelihood of detecting anterior cancers within the prostate and provide a specimen that spans the length of the gland. Newly designed 17- and 15-gauge (G) biopsy needles, a variable actuator, and an integrated pathology system intended for the longer cores were developed and tested for this purpose.

MATERIALS AND METHODS

Testing was performed comparing 2 common cannula tip grinds, a Vet-point (sharp tip) and a Menghini-point (atraumatic tip), and were tested against 18-G Bard Monopty in porcine kidney. A variable actuator was developed to fire the needle 20-60 mm and tested in cadaver prostates.

RESULTS

The aggregate firings for 3 different shot lengths comparing the Vet- with the Menghini-tip cannulas demonstrated 91% vs 85.2% fill (length of specimen/length of core bed, P = .007). A 15-G trocar needle with the Vet-tip cannula also had the best performance, with an aggregate standard deviation of 6.4% across 3 firing ranges and a minimum to maximum specimen length of 81%-105% of potential fill. Cadaver testing with the Vet-tip needles in the actuator for the transrectal (17-G) and transperineal (15-G) biopsies demonstrated mean fills of 93.3% and 76.5%, respectively. The new transrectal ultrasound needle obtained a 2-fold increase in specimen length over the standard Bard device (P <.001).

CONCLUSION

Longer and consistent cores were obtained using the new biopsy needles. Combined with an adjustable actuator, the physician can obtain specimens that include peripheral and anterior zone tissue in 1 core. Determination of cancer location on the longer specimens could enhance focal therapy planning.

Deflection Analysis of Different Needle Designs for Prostate Biopsy and Focal Therapy

OBJECTIVE

The biopsy needles currently used were designed for a transrectal biopsy and are known to experience significant deflection from the point of entry into the gland to the needle tip.

METHODS

Five designs were selected for testing: 18-gauge Bard, 15-gauge lancet tip needle with 12° vet-point cannula, and trocar tip needle with 12°, 15°, and 20° vet-point cannulas. The 15-gauge needle was designed to take a variable specimen sample between 20 and 60 mm, whereas the Bard needle specimen bed was fixed at 20 mm. The needles were bench tested on a spring-loaded platform and fired into gelatin matrix with modulus of elasticity similar to human prostate.

RESULTS

The Bard device with lancet tip needle deflected an average of 0.9 mm (range 0.3-1.3 mm) and 1.9° (range 0.6°-2.8°). Increasing needle diameter from 18-gauge Bard to 15-gauge variable with the same lancet tip needle design resulted in an average deflection across the 3 test lengths of 0.9 mm (range 0-2.0 mm) and 0.9° (range 0°-2.0°) with no significant difference. On the contrary, the use of the 3-point trocar tip needles with 12°, 15°, and 20° vet-point cannulas demonstrated significant reduction in the extent of deflection in both millimeters and degrees. There was no deflection at the 2- and 4-cm shots for both spring loads and preloads for the 3 vet tip angles tested. At 6 cm, the 20° vet tip performed the best.

CONCLUSION

We proposed a mechanism that provides more accurate prostate sampling by combining a 3-point trocar tip on the needle with a 20° vet tip on the cutting cannula. Using the phantom, mimicking prostate gland tissue density, no deflection was revealed between 20- and 60-mm biopsy lengths, which should permit a straight sample in the majority of prostate glands and improve cancer localization for focal therapy planning.

Does active surveillance lead to anxiety and stress?

For men with prostate cancer (PC), patient care and treatment recommendations should not focus solely on the disease but should also take into account the views of the patient. The diagnosis and consequences of monitoring or treatment should be fully explained. Recommending Active Surveillance (AS) for the monitoring of a proven low-risk, low-volume prostate cancer should ensure that the psychological impact of AS is taken into account and included in a holistic approach to patient and disease management. This article is a rapid literature search relating to AS, and how the psychological impact of a cancer diagnosis may influence patient choice.