Impact of relative cisplatin dose to skeletal muscle mass on adverse events in patients with head and neck cancer undergoing chemoradiotherapy.

BACKGROUND: Chemoradiotherapy (CRT) with high-dose cisplatin (CDDP) is the standard treatment for locally advanced head and neck squamous cell carcinoma (HNSCC). Although dosing is based on body surface area (BSA), some patients experience CDDP-related adverse events (AEs). We aimed to evaluate the impact of relative CDDP dose to skeletal muscle mass (SMM) on chemotherapy-associated AEs in patients with HNSCC undergoing CRT with high-dose CDDP. MATERIALS AND METHODS: We retrospectively analyzed data of patients who underwent CRT with high-dose CDDP (80-100 mg/m2, triweekly) between 2010 and 2023. SMM was measured as the cross-sectional muscle area at the third cervical vertebra (C3-SMM) using computed tomography; the skeletal muscle index (SMI) was defined as SMM normalized by squared height. The CDDP index was defined as the prescribed CDDP dose divided by SMI. CDDP-related AEs were assessed during the first cycle using Common Terminology Criteria for Adverse Events v5.0. RESULTS: Overall, 306 patients were identified. The CDDP index cutoff value best associated with grade ≥ 3 AEs was 10.312. Grade ≥ 3 hematological toxicities exhibited stronger association with high CDDP index value than with low CDDP index value (26.9% vs 16.3%, P = .033). Multivariate analysis revealed that high CDDP index value and creatinine clearance < 70 mL/minute were predictive factors for grade ≥ 3 AEs (odds ratio [OR] 2.55, P = .008; OR 3.68, P = .002, respectively). CONCLUSION: The CDDP index based on C3-SMM was an independent predictive factor for grade ≥ 3 CDDP-related AEs. C3-SMM is potentially more useful than BSA for determining the optimal CDDP dose in patients with HNSCC.

[Physics properties of non-helical scan using 320-row multi detector computed tomography].

Recently, clinical applications utilizing 320-row multi detector computed tomography (320MDCT) have increased, and the physical image properties of 320MDCT have been more concerned. We evaluated the spatial resolution in scan plane and z-direction, image noise and low-contrast sensitivity of non-helical mode (320NH), 640 slices mode by a double slice reconstruction technology (640DS), and 64-row helical mode (64HE) by using a 320MDCT. The spatial resolution in z-direction was evaluated by the section sensitivity profile (SSP) measurement with the micro coin phantom and the contrast transfer ratio (CTR) with the 0.5-mm comb phantom. The in-plane spatial resolution of 320NH was uniform over all the slice positions. The spatial resolution in z-direction decreased from the cathode side toward the anode side. The image noise of the anode side was higher than that of the cathode side. The contrast to noise ratio as index of the low contrast sensitivity was uniform over all the slice position. The CTR of 320NH fluctuated in the z-position, and the fluctuation was improved by 640DS except for the center of rotation.