Rosaleen B. Parsons

RENAL Nephrometry Scoring System: The Radiologist's Perspective

OBJECTIVEnThe 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.nnnCONCLUSIONnThe scoring system has implications for surgical planning and has been widely adopted by urologists but is less familiar to radiologists.

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.

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.

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 18F-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.

Radiation therapy for pituitary metastasis: report of four cases.

AIMS AND BACKGROUNDnTo report the clinical outcomes of four patients with pituitary metastases treated with radiotherapy.nnnMETHODSnRetrospective chart review of four cases.nnnRESULTSnThe 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.nnnCONCLUSIONSnTreatment with three-dimensional conformal radiotherapy or stereotactic radiotherapy is a suitable non-surgical option for patients with pituitary metastases.

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.

PD11-02 NON-CONTRAST IMAGING CHARACTERISTICS OF PAPILLARY RENAL CELL CARCINOMA (PRCC): IMPLICATIONS FOR DIAGNOSIS AND SUBTYPING

INTRODUCTION AND OBJECTIVES: Non-contrast CT imaging may be helpful in distinguishing cystic from solid lesions with a proposed cutoff of <20 HU. Current guidelines suggest that renal lesions<20HU on pre-contrast study require no further evaluation as they are most commonly benign cysts. We evaluated the frequency of pRCC presenting with low pre-contrast attenuation that might otherwise be considered radiographically benign, as well as the relationship of this metric to histologic subtype of pathologically proven pRCC. METHODS: The prospectively maintained Fox Chase Cancer Center kidney cancer database was reviewed for pT1 or T2 pRCC between 2003-2015. Patients were categorized by papillary subtype. Preoperative non-contrast CT images were analyzed. Maximum tumor diameter was measured in centimeters. Attenuation was calculated as the average Hounsfield Units (HU) from 6 distinct axial regions. Low attenuation was defined as 1⁄4 20 HU and high attenuation as >20 HU. We assessed the relationship between pre-operative renal mass attenuation and pRCC subtype using logistic regression controlling for stage, age, gender and laterality. RESULTS: 58 patients were identified with pT1 or pT2 pRCC in whom preoperative non-contrast CT images were evaluable. 24 (41%) had type 1 and 34 (59%) had type 2 pRCC. No significant differences were noted in age (median 66.75 vs. 63.41 years, p 1⁄4 0.23) or tumor diameter (median 5.27 vs. 6.32 cm, p 1⁄4 0.18). 27 patients (47%) exhibited an average preoperative non-contrast ROI 1⁄4 20 HU, of which 6 patients (22%) were type 1 pRCC and 21 patients (78%) were type 2 pRCC. Type 1 pRCC demonstrated a higher attenuation than type 2 tumors using both average and max attenuation (29.6 vs. 20.6 HU, p <0.01; and 37.3 vs 26.3 HU, p 1⁄4 <0.01, respectively). After adjustment, HU was an independent predictor of pRCC subtype. Relative to lowdensity tumors, high-density tumors were 80% less likely to be type 2 pRCC (OR 1⁄4 0.20, 95% CI 0.06-0.70, p1⁄40.01). CONCLUSIONS: Nearly half of our evaluated pRCC presented with low attenuation lesions (<20HU) on unenhanced CT and would have been dismissed as benign lesions under current guidelines. Importantly, we demonstrate that not only were these low attenuation lesions not benign, but theywereassociatedwith themoreaggressive type2 subtype. These data contradict the opinion that lowattenuation renal lesions require no further evaluation, and suggest that attenuation on non-contrast CT imaging is insufficient as a single parameter to rule out malignancy.

MP53-01 DEFINING DELIVERABLES OF MULTIPARAMETRIC MAGNETIC RESONANCE IMAGING (MPMRI)/ULTRASOUND (US) FUSION-GUIDED TARGETED PROSTATE BIOPSY: ACTIONABLE INTELLIGENCE METRIC (AIM) AND REDUCTION METRIC (RM)

INTRODUCTION AND OBJECTIVES: Transrectal ultrasoundguided prostate biopsy (TRUS-B) is the gold standard for prostate cancer (CaP) diagnosis. mpMRI/US fusion targeted biopsy (TB) has emerged as a technique to optimize the procedure. The ideal prostate biopsy would: (1) identify all non-low risk CaP with greater sensitivity than TRUS-B; (2) eliminate the need for unnecessary sampling. Using our institutional dataset and the available literature, the objective of the present study was to define metrics that more accurately demonstrate the deliverables of TB and facilitate meaningful data comparisons. METHODS: Patients (pts) with indications for TRUS-B having identified prostate lesions (PIRADS 3-5) on mpMRI were included. The UroNav System (Invivo) was used to obtain 1-4 TBs of each targeted lesion. All men underwent concurrent 12-core TRUS-B. Actionable intelligence metric (AIM) was defined as all pts with higher Gleason score (GS) on TB (minimum GS 3+41⁄47) relative to TRUS-B O total pts with GS 3+41⁄47 CaP (i.e. % for whom TB offered actionable data over TRUS-B). Reduction metric (RM) was defined as 1 [all pts with higher GS on TRUS-B (minimum GS 3+41⁄47) relative to TB O total pts undergoing biopsy] (i.e. % who could have foregone TRUS-B). Cohort metrics were compared to previously published data. RESULTS: 149 pts (mean age 64 7.4y, PSA 9.1 8.6 ng/ml, and prostate volume 53.6 34.2 cc) were examined: 21 (14.1%) biopsy naive men (G1), 74 (49.7%) men with prior negative TRUS-B (G2), and 54 (36.2%) men with prior positive TRUS-B on an active surveillance (AS) protocol (G3). Overall cancer detection rate was 90/149 (60.4%): 12/21 (57%) for G1, 33/74 (44.6%) for G2, and 45/54 (83.3%) for G3. AIM and RM for the entire cohort was 22.6% and 78.5%; 25% and 81.0% for G1, 28.6% and 81.1% for G2, and 12.0% and 72.2% for G3. These findings are similar to previously published cohorts in which the AIM and RM are 13.6% and 95.5% and 23.6% and 93.6% for G1 and G2, respectively. AIM and RM for men on AS is not calculable from the currently published literature. CONCLUSIONS: TB harbors potential for improvement over TRUS-B; however, deliverables of this costly technology must be outlined. We define two metrics, AIM and RM, for use in future reports to help quantify, communicate, and compare the added value of TB technology. At present, 12-core TRUS-B remains a necessary adjunct to TB, particularly in the AS setting.

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 131I 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 131I 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.

A Rare Complication of a CT-Guided Biopsy

tomography (CT) was then performed which demonstrated increased metabolic activity limited to the peripheral mass. A CT-guided biopsy (see Figure 1) was performed with the pathology consistent with a poorly differentiated non-small cell lung cancer. The tumor increased in size from 2.3 1.9 cm on the CT-guided biopsy scan only 5 weeks later. A repeat diagnostic CT with contrast was recommended and performed now demonstrating the mass to be 8.8 5.9 cm. As seen in Figure 2, there is direct extension of the tumor outside the chest wall in the exact tract of the needle (see Figure 1). This is a rare complication for patients with lung cancer,1 which is more commonly seen in aggressive malignancies.