Advanced MRI imaging techniques in pediatric brain tumors.

There is a diverse array of pediatric brain tumors with considerable associated morbidity. Like adult brain tumors, MRI serves as the primary imaging modality for pediatric brain tumors. In addition to standard sequences, more advanced MRI techniques can enhance the precision of diagnosis and assist in prognostication, and treatment planning. This paper discusses these various advanced techniques categorizing them into those that assist in identifying tissue characteristics, and those that evaluate the functional impact of tumors to aid in treatment planning.

Is the excretory phase necessary to identify upper tract urothelial neoplasms at CT urography? A 10-year population-based study.

PURPOSE: To assess the proportion of upper tract urothelial carcinomas (UTUC) that are evident without the excretory phase at CT urography (CTU), and the proportion of potentially avoidable radiation. METHODS: UTUCs diagnosed between January 2008-December 2017 were retrospectively identified from a population-based cancer registry. For each patient, US, non-urographic CT, and MRI exams were assessed for a primary mass and secondary imaging findings (hydronephrosis, urinary tract thickening, luminal distention, fat stranding, and lymphadenopathy/metastatic disease). CTUs were assessed for primary and secondary findings, and whether the tumor was evident as a filling defect on excretory phase. The dose-length product (DLP) of potentially avoidable excretory phases was calculated as a fraction of total DLP. RESULTS: 288 patients (mean age, 72±11 years, 165 males) and 545 imaging examinations were included. Of 192 patients imaged with 370 non-urographic CTs, a primary mass was evident in 154 (80.2%), secondary findings were evident in 172 (89.6%), and primary or secondary findings were evident in 179 (93.2%). Of 175 CTUs, primary and secondary findings were evident in 157 (89.7%) and 166 (94.9%) examinations, respectively, and primary or secondary findings were evident in 170/175 (97.1%). 131/175 (74.9%) UTUCs were evident as a filling defect, including the 5/175 (2.9%) UTUCs without primary or secondary findings. Of 144 CTUs with available DLP data, the proportion of potentially avoidable radiation was 103.7/235.8 (44.0%) Gy⋅cm. CONCLUSION: In our population, almost all UTUCs were evident via primary or secondary imaging findings without requiring the excretory phase. These results support streamlining protocols and pathways.

Spontaneous regression of metastatic hepatocellular carcinoma following 3 weeks of lenvatinib.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality and is associated with a poor prognosis. Rarely, there is spontaneous regression of the tumour. We present a case of a middle-aged male with presumed metastatic HCC who experienced enduring regression following 3 weeks of lenvatinib, which was discontinued due to side effects. While this could represent an unusually successful response to therapy, spontaneous tumour regression or an alternative diagnosis should be considered. We discuss possible mechanisms that might explain this unusual case and advocate for tissue confirmation in select cases, where there is diagnostic doubt or when the disease pattern does not clearly follow the recognised natural history. Therefore, if regression occurs-whether spontaneous or in response to treatment-it can be better understood and subsequent therapies recommended.