Sree Harsha Tirumani

Benign Biliary Strictures: A Current Comprehensive Clinical and Imaging Review

OBJECTIVE There is a wide spectrum of nonneoplastic causes of biliary stricture that can pose a significant challenge to clinicians and radiologists. Imaging plays a key role in differentiating benign from malignant strictures, defining the extent, and directing the biopsy. We describe the salient clinical and imaging manifestations of benign biliary strictures that will help radiologists to accurately diagnose these entities. CONCLUSION Accurate diagnosis and management are based on correlating imaging findings with epidemiologic, clinical, and laboratory data. Cross-sectional imaging modalities permit precise localization of the site and length of the segment involved, thereby serving as a road map to surgery, and permit exclusion of underlying malignancy.

Radiographic Profiling of Immune-related Adverse Events in Advanced Melanoma Patients Treated With Ipilimumab

As more melanoma patients are treated with CTLA-4 antibodies, immune-related adverse effects (irAEs) need elucidation. Radiographic imaging identified irAEs in 31% of patients, with colitis being most common. Most irAEs developed within 3 months of therapy. Ipilimumab is a promising novel immunotherapy agent and is associated with a variety of immune-related adverse events (irAE). The purpose of this study was to investigate the manifestations of irAEs on body imaging in patients with advanced melanoma treated with ipilimumab. One-hundred forty-seven patients with advanced melanoma (59 women, 88 men; median age, 64.5 years) treated with ipilimumab were studied. All patients had the baseline and at least one follow-up chest/abdomen/pelvis CT or PET/CT during therapy, which were reviewed by a consensus of two radiologists blinded to the clinical data. Findings indicative of individual types of irAEs were assessed, including thyroiditis, sarcoid-like lymphadenopathy, pneumonitis, hepatitis, pancreatitis, and colitis. Among the 147 patients, 46 (31%) had radiologically identified irAEs. The time interval from the initiation of therapy to the development of irAEs was less than 3 months in 76% (35 of 46) of the patients (range, 0.2–9.1 months). Clinical characteristics did not differ between patients with and without irAEs (P > 0.18). Among the individual types of irAEs, colitis was most common (n = 28; 19%), followed by sarcoid-like lymphadenopathy (n = 8; 5%) and pneumonitis (n = 8; 5%). Hepatitis (n = 3), thyroiditis (n = 2), and pancreatitis (n = 1) were less common. The resolution of irAEs was noted in 32 of 36 patients (89%) with further follow-up scans, with a median time of 2.3 months after the detection of irAE. In conclusion, irAEs were noted on body imaging in 31% of patients with melanoma treated with ipilimumab. Colitis was the most common, followed by sarcoid-like lymphadenopathy and pneumonitis. The results call for an increased awareness of irAEs, given the expanding role of cancer immunotherapy. Cancer Immunol Res; 3(10); 1185–92. ©2015 AACR.

Pearls and Pitfalls in MRI of Gynecologic Malignancy With Diffusion-Weighted Technique

OBJECTIVE Developments in MRI techniques have increased the role of MRI in assessment of the pelvis in women. The aims of this review are a short overview of pelvic MRI with an emphasis on diffusion-weighted MRI (DWI) and presentation of a practical approach that includes the pearls and pitfalls of DWI. CONCLUSION DWI provides indispensable information in the evaluation of gynecologic malignancies. Prudent application of this technique requires knowledge of the optimal protocols and pitfalls in interpretation.

Ovarian Carcinomatosis: How the Radiologist Can Help Plan the Surgical Approach

Ovarian carcinoma is the most common cause of death due to gynecologic malignancy. Peritoneal involvement is present in approximately 70% of patients at the time of initial diagnosis. The disease spreads abdominally by direct extension, exfoliation of tumor cells into the peritoneal space, and dissemination of tumor cells along lymphatic pathways. Carcinomatosis characterizes an advanced stage of disease in which peritoneal disease has spread throughout the upper abdomen (stage IIIC) or in which diffuse peritoneal disease is accompanied by malignant pleural infiltration or visceral metastases (stage IV). Common sites of intraperitoneal seeding of ovarian carcinoma include the pelvis, omentum, paracolic gutters, liver capsule, and diaphragm. Soft-tissue thickening, nodularity, and enhancement are all signs of peritoneal involvement. Advanced-stage disease is treated either with initial cytoreductive surgery (debulking) followed by adjuvant chemotherapy, or with initial neoadjuvant chemotherapy followed by debulking. Radiologic imaging plays an important role in the selection of patients who may benefit from neoadjuvant chemotherapy before debulking. However, accurate interpretation of the imaging findings is challenging and requires a detailed knowledge of the complex peritoneal anatomy, directionality of flow of peritoneal fluid, and specific disease sites that are likely to present particular difficulties with regard to surgical access and technique. Although there is as yet no clear consensus on the criteria for resectability of peritoneal lesions, extensive involvement of the small bowel or mesenteric root, involved lymph nodes superior to the celiac axis, pleural infiltration, pelvic sidewall invasion, bladder trigone involvement, and hepatic parenchymal metastases or implants near the right hepatic vein are considered indicative of potential nonresectability. Implants larger than 2 cm in diameter in the diaphragm, lesser sac, porta hepatis, intersegmental fissure, gallbladder fossa, or gastrosplenic or gastrohepatic ligament also may represent nonresectable disease.

Cancer Immunotherapy: Imaging Assessment of Novel Treatment Response Patterns and Immune-related Adverse Events

Cancer immunotherapy is changing the imaging evaluation of cancer treatment response and treatment-related toxic effects. New emerging patterns of treatment response and treatment-related toxic effects after treatment with immunomodulating agents have been observed. Treatment response after immunomodulatory therapy can be associated with significantly delayed decrease in tumor size, and new or enlarging tumors observed soon after completion of treatment may not reflect disease progression. In addition, activation of the immune system to fight cancer may lead to unwanted autoimmune-mediated toxic effects that could be mistaken for metastatic disease or misdiagnosed as a non-treatment-related process and delay appropriate clinical management. Radiologists must recognize the novel treatment response patterns and the wide range of autoimmune toxic effects, which should not be mistaken for treatment failure or metastatic disease progression.

Current concepts in the imaging of uterine sarcoma

Recent advances in genetics and pathology have improved our understanding of diagnosis and staging of uterine sarcomas. The major types of uterine sarcomas include leiomyosarcoma, low-grade endometrial stromal sarcoma, undifferentiated endometrial sarcoma, adenosarcoma and carcinosarcoma. The distinctive biological behavior and poor overall survival of uterine sarcoma create challenges in the management of these tumors. We herein present a comprehensive review of taxonomy, epidemiology, pathology, imaging findings and natural history of a wide spectrum of uterine sarcomas.

Update on the Role of Imaging in Management of Metastatic Colorectal Cancer

Evolution in the treatment of metastatic colorectal cancer (mCRC) has led to significant improvement in the survival of these patients. Surgery is useful in patients with resectable disease. Liver-directed therapies such as hepatic arterial infusion, transarterial radio- and chemoembolization, and percutaneous ablation are sometimes used by oncologists when the liver is the only site of metastatic disease. Unresectable mCRC is typically treated with systemic chemotherapy. First-line systemic chemotherapeutic regimens for mCRC are FOLFOX (combination of 5-fluorouracil/leucovorin [5-FU/LV] and oxaliplatin) and FOLFIRI (combination of 5-FU/LV and irinotecan) combined with molecular targeted drugs. Molecular targeted therapies that are effective in treating mCRC include antiangiogenic agents such as bevacizumab-an antibody against vascular endothelial growth factor-and antibodies directed against epidermal growth factor receptor (EGFR). EGFR-directed antibodies such as cetuximab and panitumumab have been shown to produce activity only in wild-type KRAS tumors. Imaging modalities such as multidetector computed tomography (CT), magnetic resonance imaging, and positron emission tomography/CT play a major role in the selection of appropriate treatment strategies. Assessment of treatment response in patients who undergo liver-directed and systemic therapy requires imaging at regular intervals. Recent studies have shown that alternative treatment response criteria may be more predictive of pathologic response in mCRC than conventional criteria such as Response Evaluation Criteria in Solid Tumors. Awareness of unusual response patterns, as well as of complications and toxicities, is helpful in guiding patient management.

Myxoid Soft-Tissue Neoplasms: Comprehensive Update of the Taxonomy and MRI Features

OBJECTIVE. The purpose of this article is to review the classification, clinical presentation, and histopathologic and MRI features of myxoid soft-tissue neoplasms. CONCLUSION. MRI is the modality of choice for characterization of myxoid soft-tissue tumors. A combination of imaging features (including certain characteristic signs), clinical features, and patient demographics can help the radiologist in coming to a specific diagnosis or in narrowing down the differential diagnoses.

Imatinib and Beyond in Gastrointestinal Stromal Tumors: A Radiologist's Perspective

OBJECTIVE The purpose of this article is to review the decade-long experience with imatinib and other molecular targeted agents in the treatment of gastrointestinal stromal tumor (GIST). CONCLUSION Tremendous progress has been made in the medical management of GIST since the inception of imatinib, and imaging has played a key role in understanding the typical and atypical responses of GIST to molecular targeted therapies.

Mucinous neoplasms of the appendix: a current comprehensive clinicopathologic and imaging review.

Abstract Mucinous neoplasms of the appendix are a heterogeneous group of neoplasms ranging from simple mucoceles to complex pseudomyxoma peritonei. Considerable controversy exists on their pathologic classification and nomenclature. Clear understanding of the histopathologic diversity of these neoplasms helps in establishing proper communication between the radiologist, the pathologist and the surgeon. In this article, we present a brief discussion of the current taxonomy and nomenclature of mucinous neoplasms of the appendix followed by a review of their imaging features. Important points including the significance of identifying extra-appendiceal mucin at imaging, the new classification of pseudomyxoma peritonei into low- and high-grade varieties and the significance of simultaneous ovarian and appendiceal neoplasms are highlighted.