Molecular Imaging and Therapy of Differentiated Thyroid Carcinoma in Adults.

ABSTRACT: Differentiated thyroid carcinoma (DTC) has been increasing in incidence in the United States over the last several decades, although mortality rates have remained low. Radioactive iodine therapy (RAI-T) has been a mainstay of treatment for DTC since the 1940s. Imaging of DTC before and after RAI-T primarily focuses on molecular imaging of the sodium iodide symporter. The expanding understanding of the molecular profile of DTC has increased available treatment options. Incorporation of risk stratification to treatment approaches has led to deintensification of both surgical and nonsurgical treatments, leading to decreased morbidity without compromising disease control.

Management of Dry Eye Toxicity After Treatment With 177Lu-PSMA-617 Radioligand Therapy.

Treatment options for patients with metastatic castration-resistant prostate cancer include use of radioligand therapy with 177Lu-PSMA-617. 177Lu-PSMA-617 is used to target prostate cancer cells selectively by targeting prostate specific membrane antigen (PSMA); however, PSMA is also expressed on lacrimal glands among other tissues. Herein, we report on a case of a Common Terminology Criteria for Adverse Events version 5 grade 3 dry eye event with concomitant blepharitis after administration of 177Lu-PSMA-617. The patient was managed with neomycin-polymyxin-dexamethasone 3.5-10000-0.1 ophthalmic suspension, artificial tears, lubricating ointments, lid scrubs, and oral antihistamines.

Uterine Cervical Metastasis From Primary Rectal Adenocarcinoma on PET/CT and MRI.

FDG avid uterine cervical masses are most commonly due to primary cervical carcinoma; however, history and differential diagnoses are critical when interpreting FDG PET/CT studies. A 51-year-old woman with newly diagnosed moderately differentiated adenocarcinoma of the rectum underwent FDG PET/CT for staging, which revealed the hypermetabolic primary rectal tumor and nodal metastases. Additionally, FDG avid focus in the anterior cervix without a CT correlate was present. Cervical metastasis was suspected, and further evaluation with MRI and histopathologic correlation was recommended, which confirmed cervical metastasis. This case illustrates an unusual case of FDG-avid cervical metastasis from rectal adenocarcinoma.

Determination of osteopenia in children on digital radiography compared with a DEXA reference standard.

RATIONALE AND OBJECTIVES: The aim of this study was to explore the reliability of osteopenia diagnosis based on digital radiographs of appendicular skeleton obtained as part of routine clinical practice as compared with dual-energy x-ray absorptiometry (DEXA) gold standard (Z-score <-1). MATERIALS AND METHODS: The study was an institutional review board-approved retrospective study of 58 children (mean age 12 years [4-18]). Digital radiographs of appendicular skeleton obtained within 6 months of DEXA scanning were presented in a blinded fashion to two musculoskeletal radiologists who were instructed to grade the level of mineralization. Sensitivity and specificity of each reviewer's osteopenia grading were calculated in comparison to lumbar DEXA Z-score values. Interobserver agreement was also calculated and significance evaluated with Bowker's test. RESULTS: The reviewers correctly identified 28% of all patients with severe osteopenia (Z-score ≤-2.0) as well as 26% of all patients with mild osteopenia (-2< Z-score <-1). Interobserver agreement for the correct diagnosis of bone mineral density (BMD) category ranged from 71% for normal BMD (Z-score >-1) to 0 and 25% for mild and severe osteopenia respectively. CONCLUSIONS: Visual diagnosis of osteopenia based on digital radiographs of appendicular skeleton has poor sensitivity and interobserver agreement. Clinical features and risk factors of pediatric patients should therefore guide DEXA evaluation and treatment recommendations.

Enhanced mechanical stability of microtubules polymerized with a slowly hydrolyzable nucleotide analogue.

Atomic force microscopy (AFM) has been used to investigate the local mechanical and structural properties of microtubules polymerized using guanylyl-alpha-beta-methylene diphosphonate (GMPCPP), a slowly hydrolyzable analogue of guanosine triphosphate. Using a combination of AFM imaging and local force spectroscopy, GMPCPP-polymerized microtubules have been qualitatively and quantitatively compared to paclitaxel-stabilized microtubules. GMPCPP-polymerized microtubules qualitatively display a greater resistance to destruction by the AFM probe tip during imaging and during deformation measurements and maintain structural details after indentation. In addition, using force spectroscopy taken during the indentation and collapse of individual microtubules with the AFM probe tip, an effective spring constant of the microtubule wall (kMT) for both types of microtubules was determined. The average kMT of GMPCPP-polymerized microtubules, 0.172 N/m, is more than twice that of paclitaxel-stabilized microtubules. These results complement previously reported measurements of bending experiments on GMPCPP-polymerized and paclitaxel-stabilized microtubules.