Faculty Bibliography

PURPOSE/OBJECTIVE:To determine if second-opinion review of gynaecologic oncologic (GynOnc) magnetic resonance imaging (MRI) by sub-specialized radiologists impacts patient care. METHODS:469 second-opinion MRI interpretations rendered by GynOnc radiologists were retrospectively compared to the initial outside reports. Two gynaecologic surgeons, blinded to the reports' origins, reviewed all cases with discrepancies between initial and second-opinion MRI reports and recorded whether these discrepancies would have led to a change in patient management defined as a change in treatment approach, counselling, or referral. Histopathology or minimum 6-month imaging follow-up were used to establish the diagnosis. RESULTS:Second-opinion review of GynOnc MRIs would theoretically have affected management in 94/469 (20 %) and 101/469 (21.5 %) patients for surgeons 1 and 2, respectively. Specifically, second-opinion review would have theoretically altered treatment approach in 71/469 (15.1 %) and 60/469 (12.8 %) patients for surgeons 1 and 2, respectively. According to surgeons 1 and 2, these treatment changes would have prevented unnecessary surgery in 35 (7.5 %) and 31 (6.6 %) patients, respectively, and changed surgical procedure type/extent in 19 (4.1 %) and 12 (2.5 %) patients, respectively. Second-opinion interpretations were correct in 103 (83 %) of 124 cases with clinically relevant discrepancies between initial and second-opinion reports. CONCLUSIONS:Expert second-opinion review of GynOnc MRI influences patient care. KEY POINTS/CONCLUSIONS:• Outside gynaecologic oncologic MRI examinations are often submitted for a second-opinion review. • One-fifth of MRIs had important discrepancies between initial and second-opinion interpretations. • Second-opinion review of gynaecologic oncologic MRI is a valuable clinical service.

PURPOSE/OBJECTIVE:To examine the mode of relapse detection and subsequent treatment after partial or radical nephrectomy in patients with low-risk (pT1, N0, Nx) kidney cancer. METHODS:Retrospective study on 1404 patients treated with partial or radical nephrectomy for low-risk kidney cancer from the years 2000-2012. Scans for chest imaging (X-ray or CT) and abdominal imaging (CT, MRI, or ultrasound) are tabulated. For those patients with relapse, the site, mode of detection, and symptoms were recorded. RESULTS:Twenty-one patients relapsed with a median follow-up of 4.1 years for patients who did not relapse. In 17 (81 %) patients, relapse was detected by imaging alone, while 4 (19 %) patients presented with symptoms. Of the patients who relapsed by imaging, 13 (76 %) were treated immediately, while 4 (24 %) continued observation. During the first 3 years of follow-up, 5762 imaging studies were performed to detect 8 relapses, with 6 patients receiving immediate treatment. The median number of imaging studies per patient per year for the first 3 years was 1.7 (interquartile range 1.0, 2.3) including 30 % CT, 3 % MRI, 36 % X-ray, and 31 % ultrasounds. CONCLUSION/CONCLUSIONS:We found a low yield of surveillance imaging in the first 3 years for pT1 kidney cancer. Nearly 1000 imaging studies were performed to detect one relapse that required treatment. Further studies are needed to evaluate the clinical impact of imaging surveillance according to recent guidelines.

OBJECTIVES/OBJECTIVE:To evaluate the recommendations for multiparametric prostate MRI (mp-MRI) interpretation introduced in the recently updated Prostate Imaging Reporting and Data System version 2 (PI-RADSv2), and investigate the impact of pathologic tumour volume on prostate cancer (PCa) detectability on mpMRI. METHODS:This was an institutional review board (IRB)-approved, retrospective study of 150 PCa patients who underwent mp-MRI before prostatectomy; 169 tumours ≥0.5-mL (any Gleason Score [GS]) and 37 tumours <0.5-mL (GS ≥4+3) identified on whole-mount pathology maps were located on mp-MRI consisting of T2-weighted imaging (T2WI), diffusion-weighted (DW)-MRI, and dynamic contrast-enhanced (DCE)-MRI. Corresponding PI-RADSv2 scores were assigned on each sequence and combined as recommended by PI-RADSv2. We calculated the proportion of PCa foci on whole-mount pathology correctly identified with PI-RADSv2 (dichotomized scores 1-3 vs. 4-5), stratified by pathologic tumour volume. RESULTS:PI-RADSv2 allowed correct identification of 118/125 (94 %; 95 %CI: 90-99 %) peripheral zone (PZ) and 42/44 (95 %; 95 %CI: 89-100 %) transition zone (TZ) tumours ≥0.5 mL, but only 7/27 (26 %; 95 %CI: 10-42 %) PZ and 2/10 (20 %; 95 %CI: 0-52 %) TZ tumours with a GS ≥4+3, but <0.5 mL. DCE-MRI aided detection of 4/125 PZ tumours ≥0.5 mL and 0/27 PZ tumours <0.5 mL. CONCLUSIONS:PI-RADSv2 correctly identified 94-95 % of PCa foci ≥0.5 mL, but was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL. DCE-MRI offered limited added value to T2WI+DW-MRI. KEY POINTS/CONCLUSIONS:• PI-RADSv2 correctly identified 95 % of PCa foci ≥0.5 mL • PI-RADSv2 was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL • DCE-MRI offered limited added value to T2WI+DW-MRI.

A successful paradigm shift toward personalized management strategies for patients with prostate cancer (PCa) is heavily dependent on the availability of noninvasive diagnostic tools capable of accurately establishing the true extent of disease at the time of diagnosis and estimating the risk of subsequent disease progression and related mortality. Although there is still considerable scope for improvement in its diagnostic, predictive, and prognostic capabilities, multiparametric prostate magnetic resonance imaging (MRI) is currently regarded as the imaging modality of choice for local staging of PCa. A negative MRI, that is, the absence of any MRI-visible intraprostatic lesion, has a high negative predictive value for the presence of clinically significant PCa and can substantiate the consideration of active surveillance as a preferred initial management approach. MRI-derived quantitative and semi-quantitative parameters can be utilized to noninvasively characterize MRI-visible prostate lesions and identify those patients who are most likely to benefit from radical treatment, and differentiate them from patients with benign or indolent prostate pathology that may also be visible on MRI. This literature review summarizes current strategies how MRI can be used to determine a tailored management strategy for an individual patient.

The added value of diffusion-weighted magnetic resonance imaging (DW-MRI) for the detection, localization, and staging of primary prostate cancer has been extensively reported in original studies and meta-analyses. More recently, DW-MRI and related techniques have been used to noninvasively assess prostate cancer aggressiveness and estimate its biological behavior. The present article aims to summarize the potential applications of DW-MRI for noninvasive optimization of pretherapeutic risk assessment, patient management decisions, and evaluation of treatment response.

PURPOSE/OBJECTIVE:The aim of this study was to assess the diagnostic performance of computed tomography (CT) for initial staging of non-endometrioid carcinomas of the uterine corpus. MATERIALS AND METHODS/METHODS:Waiving informed consent, the Institutional Review Board approved this Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study of 193 women with uterine papillary serous carcinomas, clear cell carcinomas, and carcinosarcomas, who underwent surgical staging between May 1998 and December 2011 and had preoperative CT within 6 weeks before surgery. Two radiologists (R1, R2) independently reviewed all CT images. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and area under the curve were calculated using operative notes and surgical pathology as the reference standard. RESULTS:The respective sensitivities and specificities achieved by R1/R2 were 0.79/0.64 and 0.87/0.75 for detecting deep myometrial invasion (MI) on CT; 0.56/0.63 and 0.93/0.79 for detecting cervical stromal invasion; 0.52/0.45 and 0.95/0.93 for detecting pelvic nodal metastases; and 0.45/0.30 and 0.98/0.98 for detecting para-aortic nodal metastases. Although CT had suboptimal sensitivity for the detection of omental disease, it had high PPV for omental seeding at surgical exploration (1.00 for R1 and 0.92 for R2). Inter-observer agreement ranged from moderate in the detection of deep MI (κ = 0.42 ± 0.06) to almost perfect in the detection of para-aortic nodal metastases (κ = 0.88 ± 0.08). CONCLUSION/CONCLUSIONS:In patients with uterine non-endometrioid carcinomas, CT is only moderately accurate for initial staging but may provide clinically valuable information by 'ruling-in' isolated para-aortic lymph node metastases and omental dissemination.

OBJECTIVES/OBJECTIVE:To evaluate the changes in prognostic impression and patient management following PET/CT in patients with vulvar and vaginal carcinoma; and to compare PET/CT findings with those of conventional imaging modalities. METHODS:We summarized prospectively and retrospectively collected data for 50 consecutive patients from our institution that enrolled in the National Oncologic PET Registry and underwent FDG-PET/CT for a suspected or known primary or recurrent vulvar/vaginal cancer. RESULTS:54/83 (65%) studies included had a diagnosis of vulvar cancer, and the remaining 29/83 (35%), a diagnosis of vaginal cancer. Following FDG-PET/CT, the physician's prognostic impression changed in 51% of cases. A change in patient management, defined as a change to/from a non-interventional strategy (observation or additional imaging), to/from an interventional strategy (biopsy or treatment), was documented in 36% of studies. The electronic records demonstrated that 95% of the management strategies recorded in the physician questionnaires were implemented as planned. MRI and/or CT were performed within one month of the FDG-PET/CT in 20/83 (24%) and 28/83 (34%) cases, respectively. FDG-PET/CT detected nodes suspicious for metastases on 29/83 (35%) studies performed. MRI and CT detected positive nodes on 6 and 11 studies respectively. Distant metastases were identified in 10 cases imaged with FDG-PET and 5 cases that had additional conventional CT imaging. All suspicious lesions seen on CT were positively identified on PET/CT. In 4 cases, an abnormality identified on PET/CT, was not seen on diagnostic CT. CONCLUSIONS:FDG-PET/CT may play an important role in the management of vulvar and vaginal carcinoma.

DW and DCE MR imaging contribute significantly to diagnosis, treatment planning, response assessment, and prognosis in personalized cancer medicine. Nevertheless, the need for further standardization of these techniques needs to be addressed. Whole-body DW MR imaging is an exciting field; however, future studies need to investigate in more depth the biologic significance of the findings depicted, their prognostic relevance, and cost-effectiveness in comparison with MDCT and PET/CT. New MR imaging probes, such as targeted or activatable contrast agents and dynamic nuclear hyperpolarization, show great promise to further improve the care of patients with cancer in the near future.

Prostate cancer is the most common noncutaneous malignancy among men in the Western world. The natural history and clinical course of prostate cancer are markedly diverse, ranging from small indolent intraprostatic lesions to highly aggressive disseminated disease. An understanding of this biologic heterogeneity is considered a necessary requisite in the quest for the adoption of precise and personalized management strategies. Molecular imaging offers the potential for noninvasive assessment of the biologic interactions underpinning prostate carcinogenesis. Currently, numerous molecular imaging probes are in clinical use or undergoing preclinical or clinical evaluation. These probes can be divided into those that image increased cell metabolism, those that target prostate cancer-specific membrane proteins and receptor molecules, and those that bind to the bone matrix adjacent to metastases to bone. The increased metabolism and vascular changes in prostate cancer cells can be evaluated with radiolabeled analogs of choline, acetate, glucose, amino acids, and nucleotides. The androgen receptor, prostate-specific membrane antigen, and gastrin-releasing peptide receptor (ie, bombesin) are overexpressed in prostate cancer and can be targeted by specific radiolabeled imaging probes. Because metastatic prostate cancer cells induce osteoblastic signaling pathways of adjacent bone tissue, bone-seeking radiotracers are sensitive tools for the detection of metastases to bone. Knowledge about the underlying biologic processes responsible for the phenotypes associated with the different stages of prostate cancer allows an appropriate choice of methods and helps avoid pitfalls.

PURPOSE:To report the long-term control and toxicity outcomes of patients with clinically localized prostate cancer, who underwent low-dose-rate prostate brachytherapy with magnetic resonance spectroscopic image (MRSI)-directed dose escalation to intraprostatic regions. METHODS AND MATERIALS:Forty-seven consecutive patients between May 2000 and December 2003 were analyzed retrospectively. Each patient underwent a preprocedural MRSI, and MRS-positive voxels suspicious for malignancy were identified. Intraoperative planning was used to determine the optimal seed distribution to deliver a standard prescription dose to the entire prostate, while escalating the dose to MRS-positive voxels to 150% of prescription. Each patient underwent transperineal implantation of radioactive seeds followed by same-day CT for postimplant dosimetry. RESULTS:The median prostate D90 (minimum dose received by 90% of the prostate) was 125.7% (interquartile range [IQR], 110.3-136.5%) of prescription. The median value for the MRS-positive mean dose was 229.9% (IQR, 200.0-251.9%). Median urethra D30 and rectal D30 values were 142.2% (137.5-168.2%) and 56.1% (40.1-63.4%), respectively. Median followup was 86.4 months (IQR, 49.8-117.6). The 10-year actuarial prostate-specific antigen relapse-free survival was 98% (95% confidence interval, 93-100%). Five patients (11%) experienced late Grade 3 urinary toxicity (e.g., urethral stricture), which improved after operative intervention. Four of these patients had dose-escalated voxels less than 1.0 cm from the urethra. CONCLUSIONS:Low-dose-rate brachytherapy with MRSI-directed dose escalation to suspicious intraprostatic regions exhibits excellent long-term biochemical control. Patients with dose-escalated voxels close to the urethra were at higher risk of late urinary stricture.