Faculty Bibliography

Editor's Note.-Articles in the RadioGraphics Update section provide current knowledge to supplement or update information found in full-length articles previously published in RadioGraphics. Authors of the previously published article provide a brief synopsis that emphasizes important new information such as technological advances, revised imaging protocols, new clinical guidelines involving imaging, or updated classification schemes. Articles in this section are published solely online and are linked to the original article.

PURPOSE/OBJECTIVE:This study reports on the development of a novel 3D procedure planning technique to provide pre-ablation treatment planning for partial gland prostate cryoablation (cPGA). METHODS:Twenty men scheduled for partial gland cryoablation (cPGA) underwent pre-operative image segmentation and 3D modeling of the prostatic capsule, index lesion, urethra, rectum, and neurovascular bundles based upon multi-parametric MRI data. Pre-treatment 3D planning models were designed including virtual 3D cryotherapy probes to predict and plan cryotherapy probe configuration needed to achieve confluent treatment volume. Treatment efficacy was measured with 6 month post-operative MRI, serum prostate specific antigen (PSA) at 3 and 6 months, and treatment zone biopsy results at 6 months. Outcomes from 3D planning were compared to outcomes from a series of 20 patients undergoing cPGA using traditional 2D planning techniques. RESULTS:Forty men underwent cPGA. The median age of the cohort undergoing 3D treatment planning was 64.8 years with a median pretreatment PSA of 6.97 ng/mL. The Gleason grade group (GGG) of treated index lesions in this cohort included 1 (5%) GGG1, 11 (55%) GGG2, 7 (35%) GGG3, and 1 (5%) GGG4. Two (10%) of these treatments were post-radiation salvage therapies. The 2D treatment cohort included 20 men with a median age of 68.5 yrs., median pretreatment PSA of 6.76 ng/mL. The Gleason grade group (GGG) of treated index lesions in this cohort included 3 (15%) GGG1, 8 (40%) GGG2, 8 (40%) GGG3, 1 (5%) GGG4. Two (10%) of these treatments were post-radiation salvage therapies. 3D planning predicted the same number of cryoprobes for each group, however a greater number of cryoprobes was used in the procedure for the prospective 3D group as compared to that with 2D planning (4.10 ± 1.37 and 3.25 ± 0.44 respectively, p = 0.01). At 6 months post cPGA, the median PSA was 1.68 ng/mL and 2.38 ng/mL in the 3D and 2D cohorts respectively, with a larger decrease noted in the 3D cohort (75.9% reduction noted in 3D cohort and 64.8% reduction 2D cohort, p 0.48). In-field disease detection was 1/14 (7.1%) on surveillance biopsy in the 3D cohort and 3/14 (21.4%) in the 2D cohort, p = 0.056) In the 3D cohort, 6 month biopsy was not performed in 4 patients (20%) due to undetectable PSA, negative MRI, and negative MRI Axumin PET. For the group with traditional 2D planning, treatment zone biopsy was positive in 3/14 (21.4%) of the patients, p = 0.056. CONCLUSIONS:3D prostate cancer models derived from mpMRI data provide novel guidance for planning confluent treatment volumes for cPGA and predicted a greater number of treatment probes than traditional 2D planning methods. This study prompts further investigation into the use of 3D treatment planning techniques as the increase of partial gland ablation treatment protocols develop.

OBJECTIVE. In recent decades, teleradiology has expanded considerably, and many radiology practices now engage in intraorganizational or extraorganizational teleradiology. In this era of patient primacy, optimizing patient care and care delivery is paramount. This article provides an update on recent changes, current challenges, and future opportunities centered around the ability of teleradiology to improve temporal and geographic imaging access. We review licensing and regulations and discuss teleradiology in providing services to rural areas and assisting with disaster response, including the response to the coronavirus disease (COVID-19) pandemic. CONCLUSION. Teleradiology can help increase imaging efficiency and mitigate both geographic and temporal discrepancies in imaging care. Technologic limitations and regulatory hurdles hinder the optimal practice of teleradiology, and future attention to these issues may help ensure broader patient access to high-quality imaging across the United States.

PURPOSE/OBJECTIVE:To demonstrate the generalizability of PRECISION findings and apply the PRECISION biopsy strategy to a contemporary cohort to characterize cancers missed by employing this strategy. MATERIALS AND METHODS/METHODS:629 men biopsied between 2/2015-9/2018 met PRECISION inclusion criteria. Men with PI-RADS 1-2 MRI were only biopsied if high clinical suspicion for cancer. Missed cancers were defined as prostate cancer (PCa) identified uniquely on systematic biopsy (SB) in men with PI-RADS 3-5 MRI, or on either SB or MRI-targeted prostate biopsy (MRI-TB) in men with PI-RADS 1-2 MRI. Outcomes included 1) clinically-significant PCa (csPCa), ≥Gleason grade group (GG) 2, detection rate (CDR), 2) missed csPCa rate upon application of PRECISION biopsy strategy, 3) GG distribution, core size, spatial orientation, and oncologic risk among missed cancers. RESULTS:Application of the PRECISION biopsy strategy to the study cohort resulted in avoidance of biopsy in 28%, similar MRI-TB CDR to PRECISION, reduction of GG1 CDR by 60%, and reduction of csPCa CDR by 19%. Missed csPCa were often <6 mm (54.5%), GG2 (67.3%), and low-risk by clinical nomogram (74.6%). GG1 cancers identified uniquely on SB were often contralateral to MRI target (46.4%), while missed csPCa was predominantly ipsilateral (81%). Limitations include biopsy of only men with high-risk clinical features among PIRADS 1-2 MRI, potentially overestimating the csPCa CDR. CONCLUSIONS:The study cohort demonstrated generalizability of PRECISION findings. Applying the PRECISION biopsy strategy greatly reduces GG1 CDR, while missing a small number of csPCa, typically small volume, low-risk, and GG2. Missed csPCa are predominantly ipsilateral to MRI target, possibly representing targeting error.

OBJECTIVE:To characterize national trends in oncologic imaging (OI) utilization. METHODS:This retrospective cross-sectional study used 2004 and 2016 CMS 5% Carrier Claims Research Identifiable Files. Radiologist-performed, primary noninvasive diagnostic imaging examinations were identified from billed Current Procedural Terminology codes; CT, MRI, and PET/CT examinations were categorized as "advanced" imaging. OI examinations were identified from imaging claims' primary International Classification of Diseases-9 and International Classification of Diseases-10 codes. Imaging services were stratified by academic practice status and place of service. State-level correlations of oncologic advanced imaging utilization (examinations per 1,000 beneficiaries) with cancer prevalence and radiologist supply were assessed by Spearman correlation coefficient. RESULTS:The national Medicare sample included 5,030,955 diagnostic imaging examinations (1,218,144 of them advanced) in 2004 and 5,017,287 diagnostic imaging examinations (1,503,490 of them advanced) in 2016. In 2004 and 2016, OI represented 3.9% and 4.3%, respectively, of all imaging versus 10.8% and 9.5%, respectively, of advanced imaging. The percentage of advanced OI done in academic practices rose from 18.8% in 2004 to 34.1% in 2016, leaving 65.9% outside academia. In 2016, 58.0% of advanced OI was performed in the hospital outpatient setting and 23.9% in the physician office setting. In 2016, state-level oncologic advanced imaging utilization correlated with state-level radiologist supply (r = +0.489, P < .001) but not with state-level cancer prevalence (r = -0.139, P = .329). DISCUSSION/CONCLUSIONS:Oncologic imaging usage varied between practice settings. Although the percentage of advanced OI done in academic settings nearly doubled from 2004 to 2016, the majority remained in nonacademic practices. State-level oncologic advanced imaging utilization correlated with radiologist supply but not cancer prevalence.