The diagnosis and treatment of pseudoprogression, radiation necrosis and brain tumor recurrence.

Radiation therapy is an important modality used in the treatment of patients with brain metastatic disease and malignant gliomas. Post-treatment surveillance often involves serial magnetic resonance imaging. A challenge faced by clinicians is in the diagnosis and management of a suspicious gadolinium-enhancing lesion found on imaging. The suspicious lesion may represent post-treatment radiation effects (PTRE) such as pseudoprogression, radiation necrosis or tumor recurrence. Significant progress has been made in diagnostic imaging modalities to assist in differentiating these entities. Surgical and medical interventions have also been developed to treat PTRE. In this review, we discuss the pathophysiology, clinical presentation, diagnostic imaging modalities and provide an algorithm for the management of pseudoprogression, radiation necrosis and tumor recurrence.

Publisher Correction to: 18F-FDG PET/CT metabolic tumor parameters and radiomics features in aggressive non-Hodgkin's lymphoma as predictors of treatment outcome and survival.

In the original publication of the article, the title was incorrectly.

18F-FDG PET/CT metabolic tumor parameters and radiomics features in aggressive non-Hodgkin's lymphoma as predictors of treatment outcome and survival.

PURPOSE: To determine whether metabolic tumor parameters and radiomic features extracted from 18F-FDG PET/CT (PET) can predict response to therapy and outcome in patients with aggressive B-cell lymphoma. METHODS: This institutional ethics board-approved retrospective study included 82 patients undergoing PET for aggressive B-cell lymphoma staging. Whole-body metabolic tumor volume (MTV) using various thresholds and tumor radiomic features were assessed on representative tumor sites. The extracted features were correlated with treatment response, disease-free survival (DFS) and overall survival (OS). RESULTS: At the end of therapy, 66 patients (80.5%) had shown complete response to therapy. The parameters correlating with response to therapy were bulky disease > 6 cm at baseline (p = 0.026), absence of a residual mass > 1.5 cm at the end of therapy CT (p = 0.028) and whole-body MTV with best performance using an SUV threshold of 3 and 6 (p = 0.015 and 0.009, respectively). None of the tumor texture features were predictive of first-line therapy response, while a few of them including GLNU correlated with disease-free survival (p = 0.013) and kurtosis correlated with overall survival (p = 0.035). CONCLUSIONS: Whole-body MTV correlates with response to therapy in patient with aggressive B-cell lymphoma. Tumor texture features could not predict therapy response, although several features correlated with the presence of a residual mass at the end of therapy CT and others correlated with disease-free and overall survival. These parameters should be prospectively validated in a larger cohort to confirm clinical prognostication.

Multifocal Supra and Infratentorial Medulloblastoma in an Adult: Histologic, Immunohistochemical, and Molecular Evaluation of a Rare Case and Review of the Literature.

Multifocal medulloblastomas (MMBs) in adults are exceedingly rare with only 5 reported cases to date. Medulloblastoma in adult differ from its childhood counterpart by being more often lateral in location, desmoplastic in morphology, and better in clinical prognosis. Little is known, however, about the characteristic features of MMB. This is particularly true for their molecular profiles. To date, molecular characteristics of multifocal medulloblastoma have been reported only once. Here, we present the second case of multifocal medulloblastoma along with its detailed morphology, imaging features, and molecular profiles with a critical review of the literature. We believe that MMB should be reported in detail to better understand their behavior, characterize their molecular profiles, and establish therapeutic protocols.

Multiple focal nodular hyperplasia lesions of the liver associated with congenital absence of the portal vein.

Congenital absence of the portal vein (CAPV) is a rare anomaly in which the intestinal and splenic venous drainage bypass the liver and drain directly into the systemic veins through various porto-systemic shunts. In this article, we illustrate a case of multiple focal nodular hyperplasia (FNH) with congenital absence of the portal vein in a male, which, to our knowledge, is the third reported case in the literature since its first description in 1793. Furthermore, we discuss the embryology of the portal vein and the Morgan and Superina classification of portosystemic anomalies, the association between portal vein agenesis and multiple FNHs, and, lastly, the use of a hepatocellular-specific MRI contrast agent as an important diagnostic tool in the confirmation of FNH.