Ultrasound-guided breast biopsy using an adapted automated cone-based ultrasound scanner: a feasibility study

Background: Among available breast biopsy techniques, ultrasound (US)-guided biopsy is preferable because it is relatively inexpensive and provides live imaging feedback. The availability of magnetic resonance imaging (MRI)-3D US image fusion would facilitate US-guided biopsy even for US occult lesions to reduce the need for expensive and time-consuming MRI-guided biopsy. In this paper, we propose a novel Automated Cone-based Breast Ultrasound Scanning and Biopsy System (ACBUS-BS) to scan and biopsy breasts of women in prone position. It is based on a previously developed system, called ACBUS, that facilitates MRI-3D US image fusion imaging of the breast employing a conical container filled with coupling medium. Purpose: The purpose of this study was to introduce the ABCUS-BS system and demonstrate its feasibility for biopsy of US occult lesions. Method: The biopsy procedure with the ACBUS-BS comprises four steps: target localization, positioning, preparation, and biopsy. The biopsy outcome can be impacted by 5 types of errors: due to lesion segmentation, MRI-3D US registration, navigation, lesion tracking during repositioning, and US inaccuracy (due to sound speed difference between the sample and the one used for image reconstruction). For the quantification, we use a soft custom-made polyvinyl alcohol phantom (PVA) containing eight lesions (three US-occult and five US-visible lesions of 10 mm in diameter) and a commercial breast mimicking phantom with a median stiffness of 7.6 and 28 kPa, respectively. Errors of all types were quantified using the custom-made phantom. The error due to lesion tracking was also quantified with the commercial phantom. Finally, the technology was validated by biopsying the custom-made phantom and comparing the size of the biopsied material to the original lesion size. The average size of the 10-mm-sized lesions in the biopsy specimen was 7.00 ± 0.92 mm (6.33 ± 1.16 mm for US occult lesions, and 7.40 ± 0.55 mm for US-visible lesions). Results: For the PVA phantom, the errors due to registration, navigation, lesion tracking during repositioning, and US inaccuracy were 1.33, 0.30, 2.12, and 0.55 mm. The total error was 4.01 mm. For the commercial phantom, the error due to lesion tracking was estimated at 1.10 mm, and the total error was 4.11 mm. Given these results, the system is expected to successfully biopsy lesions larger than 8.22 mm in diameter. Patient studies will have to be carried out to confirm this in vivo. Conclusion: The ACBUS-BS facilitates US-guided biopsy of lesions detected in pre-MRI and therefore might offer a low-cost alternative to MRI-guided biopsy. We demonstrated the feasibility of the approach by successfully taking biopsies of five US-visible and three US-occult lesions embedded in a soft breast-shaped phantom

Clinical implementation of pre-biopsy magnetic resonance imaging pathways for the diagnosis of prostate cancer

Objective: To assess the outcomes of pre-biopsy magnetic resonance imaging (MRI) pathways, as a tool in biopsy-naïve men with suspicion of prostate cancer, in routine clinical practice. Secondary outcomes included a comparison of transrectal MRI-directed biopsy (TR-MRDB) and transperineal (TP)-MRDB in men with suspicious MRI. Patients and Methods: We retrospectively assessed a two-centre cohort of consecutive biopsy-naïve men with suspicion of prostate cancer who underwent a Prostate Imaging-Reporting and Data System version 2 (PI-RADS v2) compliant pre-biopsy MRI in a single, high-volume centre between 2015 and 2019 (Centre 1). Men with suspicious MRI scans underwent TR-MRDB in Centre 1 and TP-MRDB with additional random biopsies (RB) in Centre 2. The MRI and histopathology were assessed in the same institution (Centre 1). Outcomes included: (i) overall detection rates of Grade Group (GG) 1, GG ≥2, and GG ≥3 cancer in men with suspicious MRI; (ii) Biopsy-avoidance due to non-suspicious MRI; and (iii) Cancer detection rates and biopsy-related complications between TR- and TP-MRDB. To reduce confounding bias for MRDB comparisons, inverse probability weighting (IPW) was performed for age, digital rectal examination, prostate-specific antigen (PSA), prostate volume, PSA density, and PI-RADS category. Results: Of the 2597 men included, the overall GG 1, GG ≥2, and GG ≥3 prevalence was 8% (210/2597), 27% (697/2597), and 15% (396/2597), respectively. Biopsy was avoided in 57% (1488/2597) of men. After IPW, the GG 1, GG ≥2 and GG ≥3 detection rates after TR- and TP-MRDB were comparable at 24%, 57%, and 32%; and 18%, 64%, and 38%, respectively; with mean differences of −5.7% (95% confidence interval [CI] −13% to 1.4%), 6.1% (95% CI −2.1% to 14%), and 5.7% (95% CI −1.7% to 13%). Complications were similar in TR-MRDB (0.50%) and TP-MRDB with RB (0.62%; mean difference 0.11%, 95% CI −0.87% to 1.1%). Conclusion: This high-volume, two-centre study shows pre-biopsy MRI as a decision tool is implementable in daily clinical practice. Compared to recent trials, a substantially higher biopsy avoidance rate was achieved without compromising GG ≥2/GG ≥3 detection and coinciding with lower over detection rates of GG 1 cancer. Prostate cancer detection and complication rates were comparable for TR- and TP-MRDB

A novel stereotactic prostate biopsy system integrating pre-interventional magnetic resonance imaging and live ultrasound fusion

Purpose: We developed an effective way to precisely diagnose prostate cancer using a novel prostate biopsy system that integrates pre-interventional magnetic resonance imaging with peri-interventional ultrasound for perineal navigated prostate biopsy. Materials and Methods: A total of 106 men with findings suspicious for prostate cancer (median age 66 years, prostate specific antigen 8.0 ng/ml and prostate volume 47 ml) underwent multiparametric 3 Tesla magnetic resonance imaging. Suspicious lesions were marked and data were transferred to the novel biopsy system. Using a custom-made biplane transrectal ultrasound probe mounted on a stepper we gathered 3-dimensional ultrasound data and fused them with magnetic resonance imaging data. As a result, suspicious magnetic resonance imaging lesions were superimposed over the transrectal ultrasound data. Three-dimensional biopsy planning was done, including systematic biopsies. Perineal biopsies were taken under live ultrasound guidance and the precise site of each biopsy was documented in 3 dimensions. We evaluated feasibility, safety and cancer detection. Results: Prostate cancer was detected in 63 of 106 patients (59.4%). Magnetic resonance imaging findings correlated positively with histopathology in 71 of 103 patients (68.9%). In magnetic resonance imaging lesions marked as highly suspicious, the detection rate was 95.8% (23 of 24 cases). Lesion targeted cores had a significantly higher positivity rate than nontargeted cores. The procedural targeting error of the first 2,461 biopsy cores was 1.7 mm. regarding adverse effects, 2 patients' experienced urinary retention and 1 had a perineal hematoma. Urinary tract infections did not develop. Conclusions: Perineal stereotactic prostate biopsies guided by the combination of magnetic resonance imaging and ultrasound enable effective examination of suspicious magnetic resonance imaging lesions. Each biopsy core taken is documented accurately for its location in 3 dimensions, enabling magnetic resonance imaging validation and tailored treatment planning. The morbidity of the procedure was minimal

Molecular and functional imaging for detection of lymph node metastases in prostate cancer

Contains fulltext : 118812.pdf (publisher's version ) (Open Access)Knowledge on lymph node metastases is crucial for the prognosis and treatment of prostate cancer patients. Conventional anatomic imaging often fails to differentiate benign from metastatic lymph nodes. Pelvic lymph node dissection is an invasive technique and underestimates the extent of lymph node metastases. Therefore, there is a need for more accurate non-invasive diagnostic techniques. Molecular and functional imaging has been subject of research for the last decades, in this respect. Therefore, in this article the value of imaging techniques to detect lymph node metastases is reviewed. These techniques include scintigraphy, sentinel node imaging, positron emission tomography/computed tomography (PET/CT), diffusion weighted magnetic resonance imaging (DWI MRI) and magnetic resonance lymphography (MRL). Knowledge on pathway and size of lymph node metastases has increased with molecular and functional imaging. Furthermore, improved detection and localization of lymph node metastases will enable (focal) treatment of the positive nodes only

Head-to-head Comparison of Transrectal Ultrasound-guided Prostate Biopsy Versus Multiparametric Prostate Resonance Imaging with Subsequent Magnetic Resonance-guided Biopsy in Biopsy-naïve Men with Elevated Prostate-specific Antigen: A Large Prospective Multicenter Clinical Study

Background: There is growing interest to implement multiparametric magnetic resonance imaging (mpMRI) and MR-guided biopsy (MRGB) for biopsy-naïve men with suspected prostate cancer. Objective: Primary objective was to compare and evaluate an MRI pathway and a transrectal ultrasound-guided biopsy (TRUSGB) pathway in biopsy-naïve men with prostate-specific antigen levels of ≥3 ng/ml. Design, setting, and population: A prospective, multicenter, powered, comparative effectiveness study included 626 biopsy-naïve patients (from February 2015 to February 2018). Intervention: All patients underwent prebiopsy mpMRI followed by systematic TRUSGB. Men with suspicious lesions on mpMRI also underwent MRGB prior to TRUSGB. MRGB was performed using the in-bore approach. Outcome measurements and statistical analysis: Clinically significant prostate cancer (csPCa) was defined as grade group ≥2 (Gleason score ≥3 + 4) in any core. The main secondary objectives were the number of men who could avoid biopsy after nonsuspicious mpMRI, the number of biopsy cores taken, and oncologic follow-up. Differences in proportions were tested using McNemar's test with adjusted Wald confidence intervals for differences of proportions with matched pairs. Results and limitations: The MRI pathway detected csPCa in 159/626 (25%) patients and insignificant prostate cancer (insignPCa) in 88/626 patients (14%). TRUSGB detected csPCa in 146/626 patients (23%) and insignPCa in 155/626 patients (25%). Relative sensitivity of the MRI pathway versus the TRUSGB pathway was 1.09 for csPCa (p = 0.17) and 0.57 for insignPCa (p < 0.0001). The total number of biopsy cores reduced from 7512 to 849 (–89%). The MRI pathway enabled biopsy avoidance in 309/626 (49%) patients due to nonsuspicious mpMRI. Immediate TRUSGB detected csPCa in only 3% (10/309) of these patients, increasing to 4% (13/309) with 1-yr follow-up. At the same time, TRUSGB would overdetect insignPCa in 20% (63/309). “Focal saturation” by four additional perilesional cores to MRGB improved the detection of csPCa in 21/317 (7%) patients. Compared with the literature, our proportion of nonsuspicious mpMRI cases is significantly higher (27–36% vs 49%) and that of equivocal cases is lower (15–28% vs 6%). This is probably due to the high-quality standard in this study. Therefore, a limitation is the duplication of these results in less experienced centers. Conclusions: In biopsy-naïve men, the MRI pathway compared with the TRUSGB pathway results in an identical detection rate of csPCa, with significantly fewer insignPCa cases. In this high-quality standard study, almost half of men have nonsuspicious MRI, which is higher compared with other studies. Not performing TRUS biopsy is at the cost of missing csPCa only in 4%. Patient summary: We compared magnetic resonance imaging (MRI) with MRI-guided biopsy against standard transrectal ultrasound biopsy for the diagnosis of prostate cancer in biopsy-naïve men. Our results show that patients can benefit from MRI because biopsy may be omitted in half of men, and fewer indolent cancers are detected, without compromising the detection of harmful disease. Men also need fewer needles to make a diagnosis. In biopsy-naïve patients, a magnetic resonance imaging (MRI) pathway compared with a transrectal ultrasound-guided biopsy pathway significantly reduces the detection rate of insignificant prostate cancer without impairing the detection rate of clinically significant prostate cancer. There is a potential to reduce the number of men requiring biopsy after nonsuspicious MRI to half, with an acceptable underdetection rate of 4%