An observational study to evaluate the additional benefit of dual-energy CT and phonation CT in the pre-operative local staging of laryngeal and hypopharyngeal cancers

OBJECTIVE: To evaluate the additional benefit and diagnostic accuracy of both phonation CT and dual-energy CT in comparison to the weighted average CT imaging in the local staging of laryngeal and hypopharyngeal cancers. METHODS: The institutional review board approved this prospective study and written informed consent was obtained from all patients. 90 consecutive patients underwent 64-section dual-energy CT to stage laryngeal (n=84) and hypopharyngeal (n=6) cancers. Additional limited “eee” phonation CT was performed through the larynx. Iodinedensity images was interpreted using AW Server 2.0 software, in GSI general mode. Endoscopy findings were obtained for all patients. 13 patients underwent surgery (14%) and findings from histopathological examination were obtained. Endoscopy and histopathology findings when available were used as the standard of reference for the evaluation of diagnostic performance with receiver operating characteristic (ROC) curve analysis and in terms of sensitivity and specificity. RESULTS: For pyriform sinus involvement, “eee” phonation CT showed a slightly higher accuracy than weighted-average imaging (AUC: 0.9 vs 0.878), respectively. Dualenergy CT showed a slightly higher accuracy than weighted-average imaging for thyroid cartilage invasion (AUC: 0.567 vs 0.467 respectively). Prevertebral muscle invasion was more often identified on dual-energy CT than weighted-average images, however we were not able to provide diagnostic accuracies for prevertebral muscle invasion as surgery was precluded in these patients due to locally advanced disease. Although, mild added accuracy for dual-energy and phonation was found, we do not recommend routine use of these modalities due to poor statistical significance

Differential effects of interleukin-12 and interleukin-15 on expansion of NK cell receptor-expressing CD8+ T cells

The cytolytic activity of cells expressing natural killer cell receptors (NKRs) depends on the balance between stimulatory and inhibitory signals. We investigated both inhibitory NK receptor (CD94/NKG2A) expression and stimulatory NKR (NKG2D) expression on T cells after stimulation with cytokines (IL-12 or IL-15). Cytolytic NKR-expressing CD8+ T cells were expanded from normal adult peripheral blood mononuclear cells using anti-CD3 monoclonal antibody and cytokines (IL-12 or IL-15). The proportion and absolute number of CD94/NKG2A-expressing T cells expanded by IL-12 were significantly larger than those of the cells expanded by IL-15. On the other hand, the proportion and absolute number of NKG2D-expressing T cells expanded by IL-15 were significantly larger than those of the cells expanded by IL-12. The proportions of NKG2D and intracellular granzyme A expression in CD94-expressing cells were much more increased in PBMCs cultured with IL-15 than those of cells cultured with IL-12. A real-time polymerase chain reaction assay showed that there was a 1.68-fold increase in NKG2D mRNA expression level and a 1.37-fold increase in DAP10 mRNA expression level in CD94-expressing cells expanded by IL-15 compared with those of the cells expanded by IL-12. The cytolytic activity levels of purified CD94-expressing cells from 8-day culture with IL-15 tested against 51Cr-labeled K562 cells by standard 4-h 51Cr release assays without prior sensitization were much higher than those of cells from 8-day culture with IL-12. IL-15 appears to be able to enhance the cytolytic activity of CD94/NKG2A-expressing cells through induction of NKG2D and intracellular granzyme expression much more efficiently than does IL-12