Hypoxia-inducible factor 1 alpha (HIF-1α) is a transcription factor that regulates the cellular response to hypoxia and is upregulated in all types of solid tumor, leading to tumor angiogenesis, growth, and resistance to therapy. Hepatocellular carcinoma (HCC) is a highly vascular tumor, as well as a hypoxic tumor, due to the liver being a relatively hypoxic environment compared to other organs. Trans-arterial chemoembolization (TACE) and trans-arterial embolization (TAE) are locoregional therapies that are part of the treatment guidelines for HCC but can also exacerbate hypoxia in tumors, as seen with HIF-1α upregulation post-hepatic embolization. Hypoxia-activated prodrugs (HAPs) are a novel class of anticancer agent that are selectively activated under hypoxic conditions, potentially allowing for the targeted treatment of hypoxic HCC. Early studies targeting hypoxia show promising results; however, further research is needed to understand the effects of HAPs in combination with embolization in the treatment of HCC. This review aims to summarize current knowledge on the role of hypoxia and HIF-1α in HCC, as well as the potential of HAPs and liver-directed embolization.
Background The burgeoning interest in ChatGPT as a potentially useful tool in medicine highlights the necessity for systematic evaluation of its capabilities and limitations. Purpose To evaluate the accuracy, reliability, and repeatability of differential diagnoses produced by ChatGPT from transcribed radiologic findings. Materials and Methods Cases selected from a radiology textbook series spanning a variety of imaging modalities, subspecialties, and anatomic pathologies were converted into standardized prompts that were entered into ChatGPT (GPT-3.5 and GPT-4 algorithms; April 3 to June 1, 2023). Responses were analyzed for accuracy via comparison with the final diagnosis and top 3 differential diagnosis provided in the textbook, which served as the ground truth. Reliability, defined based on the frequency of algorithmic hallucination, was assessed through the identification of factually incorrect statements and fabricated references. Comparisons were made between the algorithms using the McNemar test and a generalized estimating equation model framework. Test-retest repeatability was measured by obtaining 10 independent responses from both algorithms for 10 cases in each subspecialty, and calculating the average pairwise percent agreement and Krippendorff α. Results A total of 339 cases were collected across multiple radiologic subspecialties. The overall accuracy of GPT-3.5 and GPT-4 for final diagnosis was 53.7% (182 of 339) and 66.1% (224 of 339;
Benign metastasizing leiomyomas are benign disseminated extrauterine tumors in patients with prior history of uterine leiomyomas and may occur years after hysterectomy. The lung is mostly affected, with a less common occurrence in the brain, heart, spine, retroperitoneum, and bone. We present the role of 18F-FDG PET/CT in the metabolic staging and postsurgical monitoring of a patient with lung and femoral involvement.
A 45-year old man had a history of dystrophic epidermolysis bullosa (EB) with distal right upper extremity amputation, esophagectomy and anterior mediastinal colonic interposition. He had a recent EB complication of cutaneous squamous cell carcinoma with biopsy proven right axillary nodal metastasis. F-18 FDG PET/CT showed the tracer-avid right axillary metastasis, benign features of brown adipose tissue of bilateral supraclavicular regions and reactive left axillary nodal uptake (based on subsequent tissue sampling). The PET/CT exam is mostly remarkable for the diffusely prominent tracer uptake by the colonic interposition and remainder of the colon (fig. 1 a & b) with corresponding retrosternal location of the colonic interposition on chest radiograph and chest CT (Fig. 1 c & d). Epidermolysis bullosa (EB) represents a group of skin diseases, with different phenotypes, characterized by blistering lesions of the dermal-epidermal basement membrane. EB may also target the epithelial-associated tissues such as external eye, upper airways, gastrointestinal tract especially esophagus, and genitourinary tract with potential development of skin malignancy such as squamous cell cancer and melanoma. Our patient had the colonic interposition procedure secondary to EB-induced esophageal lesions and stenosis. The colonic interposition procedure, with relatively high postoperative morbidity and mortality, is usually a second option following esophagectomy when the first option of gastric pull-through is not possible due to existing gastric lesions or other clinical and anatomic conditions. The colon interposition procedure may re-locate the right or left colon in the anterior mediastinal, posterior mediastinal or subcutaneous position. A comprehensive meta-analytic review showed that the most optimal and safest colonic conduit with lowest surgical morbidity and mortality is the left colonic interposition in the retrosternal/anterior mediastinal location. The diffusely prominent F-18 FDG PET/CT features of the colonic interposition and remainder of the colon may be related to our patient's subsequent inflammatory involvement occurring through the clinical course of EB.
Prostate cancer imaging has evolved significantly with the introduction of 18 F DCFPyL positron emission tomography/computed tomography (PET/CT), a novel radiotracer targeting the prostate-specific membrane antigen (PSMA). This promising imaging modality has demonstrated superior sensitivity and specificity for detecting local, regional, and distant recurrences compared with conventional imaging modalities. This article aims to provide a comprehensive overview of the practical interpretation of 18 F DCFPyL PET/CT in the management of prostate cancer, including its advantages, potential pitfalls, and comparison to other imaging techniques. Through a better understanding of 18 F DCFPyL PET/CT, clinicians can more effectively incorporate this advanced imaging tool into routine clinical practice, ultimately optimizing prostate cancer diagnosis, staging, and management.
