High Precision Bone Cutting by Er: YAG Lasers Might Minimize the Invasiveness of Navigated Brain Biopsies

Biopsies of brain tissue are sampled and examined to establish a diagnosis and to plan further treatment, e.g. for brain tumors. The neurosurgical procedure of sampling brain tissue for histologic examination is still a relatively invasive procedure that carries several disadvantages. The “proof of concept”-objective of this study is to answer the question if laser technology might be a potential tool to make brain biopsies less invasive, faster and safer. Laser technology might carry the opportunity to miniaturize the necessary burr hole and also to angulate the burr hole much more tangential in relation to the bone surface in order to take biopsies from brain regions that are usually only difficult and hazardous to access. We examined if it is possible to miniaturize the hole in the skull bone to such a high extent that potentially the laser-created canal itself may guide the biopsy needle with sufficient accuracy. The 2-dimensional, i.e. radial tolerance of the tip of biopsy needles inserted in these canals was measured under defined lateral loads which mimic mechanical forces applied by a surgeon. The canals through the skull bones were planned in angles of 90° (perpendicular) and 45° relative to the bone surface. We created a total of 33 holes with an Er : YAG laser in human skull bones. We could demonstrate that the achievable radial tolerance concerning the guidance of a biopsy needle by a laser created bone canal is within the range of the actual accuracy of a usual navigated device if the canal is at least 4 mm in length. Lateral mechanical loads applied to the biopsy needle had only minor impact on the measurable radial tolerance. Furthermore, in contrast to mechanical drilling systems, laser technology enables the creation of bone canals in pointed angles to the skull bone surface. The latter opens the perspective to sample biopsies in brain areas that are usually not or only hazardous to access.

Application of 16 G Biopsy Needle in Transperineal Template-Guided Prostate Biopsy

<b><i>Background:</i></b> The aim of this study was to evaluate the clinical value of 16 G biopsy needle in transperineal template-guided prostate biopsy (TTPB), compared with 18 G biopsy needle. <b><i>Methods:</i></b> The patients who underwent TTPB from August 2020 to February 2021 were randomized into 2 groups using a random number table. The control group (<i>n</i> = 65) and the observation group (<i>n</i> = 58) performed biopsy with 18 G (Bard MC l820) and 16 G (Bard MC l616) biopsy needles, respectively. Positive rate of biopsy, Gleason score, complications, and pain score were statistically analyzed. <b><i>Results:</i></b> The age, prostate volume, PSA, and the number of cores were comparable between the 2 groups. The positive rate of biopsy in the observation group was 68.9% (40/58), meanwhile the control group was 46.2% (30/65). There was statistical difference between the 2 groups (<i>p</i> = 0.011). Gleason score of the observation group (8 [7–9]) was higher than that of the control group (8 [6–9]) (<i>p</i> = 0.038). There was no significant difference in pain score and complications including hematuria, hematospermia, perineal hematoma, infection, and urinary retention between the 2 groups (<i>p</i> &#x3e; 0.05). <b><i>Conclusions:</i></b> 16 G biopsy needle significantly improved the positive rates and accurately evaluate the nature of lesions, meanwhile did not increase the incidence of complications compared with 18 G biopsy needle.

In vitro CT visualization of the biopsy location by filling the core biopsy needle with contrast media

Background When performing computed tomography (CT)-guided biopsy procedures with non-disposable, automatic biopsy instruments, the actual course of the biopsy needle is not registered. Purpose To evaluate the ability to visualize the sampling location after CT-guided biopsy in vitro using a novel method, where the space between the inner needle and the outer cannula in a core biopsy needle is filled with contrast media; and to compare the grade of visibility for two different concentrations of contrast media. Material and Methods Core needle biopsies were performed in a tissue phantom using biopsy needles primed with two different iodine contrast media concentrations (140 mg I/mL and 400 mg I/mL). Commercially available needle-filling contraptions with sealing membranes were used to fill the needles. Each biopsy was imaged with CT, and the visibility was evaluated twice by three senior radiologists in a randomized order. Results The presence of traces was confirmed after biopsy, almost without exception for both concentrations. The visibility was sufficient to determine the biopsy location in all observations with the 400 mg I/mL filling, and in 7/10 observations with the 140 mg I/mL filling. The grade of visibility of the trace and the proportion of the biopsy needle course outlined were higher with the 400 mg I/mL filling. Conclusion With CT-guided biopsy in vitro, the sampling location can be visualized using a novel method of priming the biopsy needle with iodine contrast media, specifically highly concentrated contrast media.

Birmingham Intervention Tent Technique (BITT): A Technical Note

Objective We describe a novel and safe CT biopsy technique that we have termed the “Birmingham intervention tent technique (BITT).” This technique is ideal for biopsying osseous lesions where a direct approach is not possible due to difficult positioning. Methods The BITT uses a plastic surgical forceps clamp attached at an angle to the biopsy needle, creating a tent shape. The finger rings of the forceps is stabilized on the table. Results In our institution, we have already used the BITT successfully in over 10 cases. Conclusion The BITT is an inexpensive and reproducible technique.

Preliminary Evaluation of Hydraulic Needle Delivery System for MRI Guided Prostate Biopsy Procedures

In clinical routine, the prostate biopsy procedure is performed with the guidance of transrectal ultrasound (TRUS) imaging to diagnose prostate cancer. However, the TRUS-guided prostate biopsy brings reliability concerns due to the lack of contrast difference between prostate tissue and lesions. In this study, a novel hydraulic needle delivery system that is designed for performing MRI-guided prostate biopsy procedure with transperineal approach is introduced. The feasibility of the overall system was evaluated through in-vitro phantom experiments under an MRI guidance. The in vitro experiments performed using a certified prostate phantom (incorporating MRI visible lesions). MRI experiments showed that overall hydraulic biopsy needle delivery system has excellent MRI compatibility (SNR Loss &lt; 3%), provides acceptable targeting accuracy (average 2.05±0.46 mm) and procedure time (average 40 minutes).