Feasibility and Outcomes of Renal Mass Biopsy for Anatomically Complex Renal Tumors.

OBJECTIVE: To compare the feasibility and outcomes of renal mass biopsies (RMB) of anatomically complex vs non-complex renal masses. METHODS: Our institutional renal tumor database was queried for patients who underwent RMB between 2005 and 2019 and with available nephrometry score. Complex masses were: (1) small (<2 cm), (2) entirely endophytic (nephrometry E=3), (3) hilar (h) or (4) partially endophytic (E=2) and anterior. Demographic and pathologic data were compared. Biopsies were deemed adequate if they resulted in a diagnosis. Concordance with surgical pathology was assessed. These were both presented using proportions. Factors associated with biopsy outcomes were identified using multivariable logistic regression. RMB sensitivity and specificity were calculated using contingency methods. RESULTS: A total of 306 RBMs were included, 179 complex and 127 non-complex. A total of 199 (65%) had an extirpative procedure. Complex lesions were less likely to have an adequate biopsy (89% vs 96%, P = .03), and to be concordant with final surgical pathology from an oncologic standpoint (89% vs 97%, P = .03). There was no significant difference in concordance of histology (76% vs 86%, P = .10) or grade (48 vs 51%, P = .66). On multivariable analyses, only male gender was associated with biopsy adequacy (OR 3.31, 95% CI 1.28-8.55, P = .01). Our overall sensitivity was 93%, specificity 93%, and accuracy 93%. There were no significant differences over time in biopsy outcomes during the study period. CONCLUSION: RMB of complex lesions is associated with excellent diagnostic yield, albeit lower than non-complex lesions. RMB should not be deferred in cases of anatomically complex lesions where additional data could improve clinical decision-making.

Variability of the Positive Predictive Value of PI-RADS for Prostate MRI across 26 Centers: Experience of the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel.

Background Prostate MRI is used widely in clinical care for guiding tissue sampling, active surveillance, and staging. The Prostate Imaging Reporting and Data System (PI-RADS) helps provide a standardized probabilistic approach for identifying clinically significant prostate cancer. Despite widespread use, the variability in performance of prostate MRI across practices remains unknown. Purpose To estimate the positive predictive value (PPV) of PI-RADS for the detection of high-grade prostate cancer across imaging centers. Materials and Methods This retrospective cross-sectional study was compliant with the HIPAA. Twenty-six centers with members in the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel submitted data from men with suspected or biopsy-proven untreated prostate cancer. MRI scans were obtained between January 2015 and April 2018. This was followed with targeted biopsy. Only men with at least one MRI lesion assigned a PI-RADS score of 2-5 were included. Outcome was prostate cancer with Gleason score (GS) greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2). A mixed-model logistic regression with institution and individuals as random effects was used to estimate overall PPVs. The variability of observed PPV of PI-RADS across imaging centers was described by using the median and interquartile range. Results The authors evaluated 3449 men (mean age, 65 years ± 8 [standard deviation]) with 5082 lesions. Biopsy results showed 1698 cancers with GS greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2) in 2082 men. Across all centers, the estimated PPV was 35% (95% confidence interval [CI]: 27%, 43%) for a PI-RADS score greater than or equal to 3 and 49% (95% CI: 40%, 58%) for a PI-RADS score greater than or equal to 4. The interquartile ranges of PPV at these same PI-RADS score thresholds were 27%-44% and 27%-48%, respectively. Conclusion The positive predictive value of the Prostate Imaging and Reporting Data System was low and varied widely across centers. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Milot in this issue.

Non-contrast imaging characteristics of papillary renal cell carcinoma: implications for diagnosis and subtyping.

INTRODUCTION: Current radiographic guidelines suggest unenhanced renal lesions < 20 Hounsfield Units (HU) are overwhelmingly benign, requiring no further evaluation. We evaluate our experience with papillary renal cell carcinoma (pRCC) presenting with low pre-contrast attenuation and the relationship of attenuation with histologic pRCC subtype. MATERIALS AND METHODS: We reviewed our institutional kidney cancer database for patients with pT1 or pT2 pRCC between 2003-2017. Tumors were categorized by papillary subtype by expert uropathologists. Preoperative CT images were analyzed at six regional tumor locations. Low, presumably benign, unenhanced median attenuation was defined as ≤ 20 HU. We calculated the frequency of pRCC with low attenuation and assessed the relationship between attenuation and pRCC subtype using logistic regression. RESULTS: Sixty-one patients with evaluable imaging were included. Median tumor size was 6 cm (1.7 cm-15.3 cm) with 39% (n = 24) type-1 and 61% (n = 37) type-2. Half of all pRCC tumors (n = 30) exhibited very low pre-contrast attenuation (< 20 HU), risking misdiagnosis as benign using current guidelines. Of these, 80% (n = 24) were type-2 with significant biological potential. Overall, type-2 tumors demonstrated a lower pre-contrast attenuation than type-1 (median HU: 19.8 (1.5-42.3) versus 29.6 HU (10-45.8), p < 0.01; max HU: 25.3 versus 36.5 HU, p < 0.01). After adjustment, lower pre-contrast HU was an independent predictor of pRCC subtype associated with a 5.5-fold increase of being type-2 (OR = 5.47, p < 0.01). CONCLUSION: pRCCs may exhibit very low attenuation on pre-contrast CT. This appears more common among the more aggressive type-2 subtype. These data suggest that low attenuation (< 20 HU) alone on non-contrast CT imaging is insufficient as a single parameter to rule out malignancy.

Defining Novel and Practical Metrics to Assess the Deliverables of Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion Prostate Biopsy.

PURPOSE: Multiparametric magnetic resonance/ultrasound targeted prostate biopsy is touted as a tool to improve prostate cancer care and yet its true clinical usefulness over transrectal ultrasound guided prostate biopsy has not been systematically analyzed. We introduce 2 metrics to better quantify and report the deliverables of targeted biopsy. MATERIALS AND METHODS: We reviewed our prospective database of patients who underwent simultaneous multiparametric magnetic resonance/ultrasound targeted prostate biopsy and transrectal ultrasound guided prostate biopsy. Actionable intelligence metric was defined as the proportion of patients in whom targeted biopsy provided actionable information over transrectal ultrasound guided prostate biopsy. Reduction metric was defined as the proportion of men in whom transrectal ultrasound guided prostate biopsy could have been omitted. We compared metrics in our cohort with those in prior reports. RESULTS: A total of 371 men were included in study. The actionable intelligence and reduction metrics were 22.2% and 83.6% in biopsy naïve cases, 26.7% and 84.2% in prior negative transrectal ultrasound guided prostate biopsy cases, and 24% and 77.5%, respectively, in active surveillance cases. No significant differences were observed among the groups in the actionable intelligence metric and the reduction metric (p = 0.89 and 0.27, respectively). The actionable intelligence metric was 25.0% for PI-RADS™ (Prostate Imaging Reporting and Data System) 3, 27.5% for PI-RADS 4 and 21.7% for PI-RADS 5 lesions (p = 0.73). Transrectal ultrasound guided prostate biopsy could have been avoided in more patients with PI-RADS 3 compared to PI-RADS 4/5 lesions (reduction metric 92.0% vs 76.7%, p <0.01). Our results compare favorably to those of other reported series. CONCLUSIONS: The actionable intelligence metric and the reduction metric are novel, clinically relevant quantification metrics to standardize the reporting of multiparametric magnetic resonance/ultrasound targeted prostate biopsy deliverables. Targeted biopsy provides actionable information in about 25% of men. Reduction metric assessment highlights that transrectal ultrasound guided prostate biopsy may only be omitted after carefully considering the risk of missing clinically significant cancers.

Splenogonadal fusion: a rare etiology of solid testicular mass.

A 35-year-old man presented with a painless left scrotal mass. Pathologic examination after orchiectomy revealed splenogonadal fusion. Splenogonadal fusion is an exceptionally rare, typically benign, congenital anomaly. Splenogonadal fusion should be included in the differential diagnosis of a left-sided testicular mass.

False-positive scalp activity in 131I imaging associated with hair coloring.

A patient with metastatic papillary thyroid carcinoma (after surgical resection of tumor and positive lymph nodes) undergoing thyroid ablation therapy with (131)I is described. Whole-body scintigraphy was performed 1 wk after ablation therapy to evaluate the presence of residual disease. The whole-body images demonstrated an artifact caused by tracer accumulation in the patient's scalp related to recent hair coloring. Common etiologies of false-positive (131)I scintigraphic findings are briefly reviewed. The importance of taking preventative measures to decrease the number of false-positive findings and recognizing these findings when they occur is discussed.

Oncology imaging in the abdomen and pelvis: where cancer hides.

As the incidence of cancer continues to increase, imaging will play an ever more important role in the detection, diagnosis, staging, surveillance, and therapeutic monitoring of cancer. Diagnostic errors in the initial discovery of cancer or at follow-up assessments can lead to missed opportunities for curative treatments or altering or reinitiating therapies, as well as adversely impact clinical trials. Radiologists must have an understanding of cancer biology, treatments, and imaging appearance of therapeutic effects and be mindful that metastatic disease can involve virtually any organ system. Knowledge of patient history and tumor biology allows for optimizing imaging protocols. The majority of cancer imaging utilizes computed tomography, where contrast enhancement characteristics of lesions can be exploited and detection of subtle lesions can involve manipulation of window width and level settings, multiplanar reconstruction, and maximum intensity projections. For magnetic resonance imaging, diffusion-weighted imaging can render lesions more conspicuous, improve characterization, and help assess therapeutic response. Positron emission tomography with (18)F-labeled fluorodeoxyglucose and sodium fluoride are invaluable in detecting occult existing and new cancerous lesions, characterizing indeterminate lesions, and assessing treatment effects. The most common anatomic "hiding places" for cancer include metastases to solid organs, such as the kidneys and pancreas, gastrointestinal tract, peritoneum and retroperitoneum, neural axis, muscular body wall, and bones. Consistent work habits, employment of appropriate technologies, and particular attention to the above anatomic areas can enhance detection, staging, and reassessments of these complex and often stealthy diseases, ensuring the radiologists' integral role in the cancer care team.

RENAL nephrometry scoring system: the radiologist's perspective.

OBJECTIVE: The nephrometry score, which is determined from cross-sectional imaging, stratifies renal masses into low, intermediate, and high complexity. The purpose of this article is to understand how the score is determined and review the five key features that contribute to the nephrometry score. CONCLUSION: The scoring system has implications for surgical planning and has been widely adopted by urologists but is less familiar to radiologists.

Radiation therapy for pituitary metastasis: report of four cases.

AIMS AND BACKGROUND: To report the clinical outcomes of four patients with pituitary metastases treated with radiotherapy. METHODS: Retrospective chart review of four cases. RESULTS: The mean age of the patients was 66 years; two were women and two were men. The mean duration of symptoms at initial presentation of the primary tumor was 2.25 months. The location of the primary tumor was the breast in one case and the lung in three. Magnetic resonance imaging of the brain revealed sellar masses in all cases. The mean interval between the primary tumor diagnosis and the development of pituitary metastases was 22.5 months. The metastases were treated with radiation therapy (palliative/stereotactic/intensity modulated) at a mean dose of 3219 cGy. At the last follow-up, three patients were dead and one was alive. CONCLUSIONS: Treatment with three-dimensional conformal radiotherapy or stereotactic radiotherapy is a suitable non-surgical option for patients with pituitary metastases.

Findings of intramediastinal gossypiboma with F-18 FDG PET in a melanoma patient.

FDG PET/CT scan was performed to evaluate recurrence in an asymptomatic 64-year-old man with a history of melanoma in the left posterior ear. PET/CT images showed an intense ring-shaped area of FDG activity in the posterior mediastinum in a large posterior mediastinal mass. However, further evaluation indicated that this activity was caused by an intramediastinal gossypiboma after coronary artery bypass graft surgery 4 years before the PET/CT scan.

Fabry disease: renal sonographic and magnetic resonance imaging findings in affected males and carrier females with the classic and cardiac variant phenotypes.

OBJECTIVE: To describe the renal ultrasonography (US) and magnetic resonance imaging (MRI) findings in affected males and female carriers with the classic and cardiac variant phenotypes of Fabry disease (alpha-galactosidase A [alpha-Gal A] deficiency). METHODS: The renal US and MRI features of 76 classically affected males (aged 7-53 years), 40 female carriers from classically affected families (aged 18-66 years), and 6 males with the cardiac variant phenotype (aged 17-59 years) were reviewed by 3 blinded board-certified radiologists. The images were evaluated for the presence of cortical cysts, parapelvic cysts, renal atrophy, decreased cortical thickness, increased echogenicity (US only), and decreased corticomedullary differentiation (MRI only). The consensus findings were analyzed with respect to the patients' sex, age, Fabry genotype and phenotype, and renal function. RESULTS: MRI was more sensitive than US in detecting radiographic abnormalities. In the 76 classically affected males, the most common US abnormalities were cysts (36.9%; cortical cysts = 22.4%, parapelvic cysts = 14.5%), increased echogenicity (17.1%), and decreased cortical thickness (11.9%), whereas the most common MRI abnormalities were cysts (47.3%; cortical cysts = 28.9%, parapelvic cysts = 18.4%), loss of corticomedullary differentiation (43.4%), and decreased cortical thickness (7.9%). Among the 40 female carriers, common US abnormalities included cysts (20%; cortical cysts = 10%, parapelvic cysts = 10%) and increased echogenicity (7.5%), whereas MRI findings included decreased corticomedullary differentiation (40%) and cysts (37.5%; cortical cysts = 20%; parapelvic cysts = 17.5%). Renal US and MRI were normal in 5 classically affected males aged 12 years or younger and 2 female carriers aged 20 years or younger. Among the 6 male cardiac variants, abnormal US findings included cysts (66.3%; cortical cysts = 50%, parapelvic cysts = 16.3%) and increased echogenicity (33.3%), whereas MRI detected decreased corticomedullary differentiation in all (100%) and cysts in 83% (cortical cysts = 66.7%; parapelvic cysts = 16.3%). Serum creatinine levels were elevated (>1.2 mg/dL) in 40.8% and 15% of the classically affected males and female carriers with US and/or MRI abnormalities compared with 14.8% and 0%, respectively, who had elevated serum creatinine levels but no detectable radiographic abnormalities. There was no association of alpha-Gal A genotype with type or frequency of abnormalities in classically affected patients. CONCLUSIONS: Among classically affected males and female carriers, renal US and/or MRI abnormalities were detected in 64.5% and 60%, respectively. The occurrence and number of abnormalities increased with age in affected males and female carriers. Cysts, particularly parapelvic cysts, were more common and appeared earlier than in the general population. No renal abnormalities were detected in classically affected males or female carriers <12 years or <20 years of age, respectively. Five of the 6 males with the later-onset milder cardiac variant phenotype had loss of corticomedullary differentiation on MRI. Renal imaging abnormalities were more frequent in older patients with elevated serum creatinine levels, regardless of alpha-Gal A genotype or Fabry phenotype.

Radiographic assessment of airway tumors.

The initial imaging evaluation of a patient with a suspected tracheal abnormality is the chest radiograph, which is poor for detection of central airway lesions. Prior to the development of CT, planar tomography was performed to better evaluate the deep layers of the chest. Tomography is rarely performed today for chest imaging. There have been major advances in chest radiography techniques secondary to improvements in electronics and computer technology that might ultimately improve plain film assessment of the central airways.