Radiomic Assessment of Radiation-Induced Alterations of Skeletal Muscle Composition in Head and Neck Squamous Cell Carcinoma within the Currently Clinically Defined Optimal Time Window for Salvage Surgery-A Pilot Study

Matthias Santer; Herbert Riechelmann; Benedikt Hofauer; Joachim Schmutzhard; Wolfgang Freysinger; Annette Runge; Timo Maria Gottfried; Philipp Zelger; Gerlig Widmann; Hanna Kranebitter; Stephanie Mangesius; Julian Mangesius; Florian Kocher; Daniel Dejaco

doi:10.3390/cancers15184650

Radiomic Assessment of Radiation-Induced Alterations of Skeletal Muscle Composition in Head and Neck Squamous Cell Carcinoma within the Currently Clinically Defined Optimal Time Window for Salvage Surgery-A Pilot Study

Cancers (Basel). 2023 Sep 20;15(18):4650. doi: 10.3390/cancers15184650.

Affiliations

¹ Department of Otorhinolaryngology-Head and Neck Surgery, Medical University of Innsbruck, 6020 Innsbruck, Austria.
² Department for Hearing, Voice and Speech Disorders, Medical University of Innsbruck, 6020 Innsbruck, Austria.
³ Department of Radiology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
⁴ Department of Neuroradiology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
⁵ Department of Radiation-Oncology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
⁶ Department of Internal Medicine V (Hematology and Oncology), Comprehensive Cancer Center Innsbruck (CCCI), Medical University of Innsbruck, 6020 Innsbruck, Austria.

Abstract

Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) frequently require primary radiochemotherapy (RCT). Despite intensity modulation, the desired radiation-induced effects observed in HNSCC may also be observed as side effects in healthy tissue, e.g., the sternocleidomastoid muscle (SCM). These side effects (e.g., tissue fibrosis) depend on the interval between the completion of RCT and restaging CT. For salvage surgery, the optimal time window for surgery is currently clinically postulated at between 6 and 12 weeks after completion of RCT. Thus, no extensive tissue fibrosis is to be expected. This interval is based on clinical studies exploring surgical complications. Studies directly exploring radiation-induced changes of the SCM in HNSCC patients are sparse. The present study quantified tissue alterations in the SCM and paravertebral musculature (PVM) after RCT, applying radiomics to determine the optimal time window for salvage surgery. Three radiomic key parameters, (1) volume, (2) mean positivity of pixels (MPP), and (3) uniformity, were extracted with mint Lesion^TM in the staging CTs and restaging CTs of 98 HNSCC patients. Of these, 25 were female, the mean age was 62 (±9.6) years, and 80.9% were UICC Stage IV. The mean restaging interval was 55 (±28; range 29-229) days. Only the mean volume significantly decreased after RCT, from 9.0 to 8.4 and 96.5 to 91.9 mL for the SCM and PVM, respectively (both p = 0.007, both Cohen's d = 0.28). In addition, the mean body mass index (BMI) decreased from 23.9 (±4.2) to 21.0 (±3.6) kg/m² (p < 0.001; Cohen's d = 0.9). The mean BMI decreased significantly and was correlated with the volume decrease for the SCM (r = 0.27; p = 0.007) and PVM (r = 0.41; p < 0.001). If t-test p-values were adjusted for the BMI decrease, no significant change in volumes for the SCM and PVM was observed (both p > 0.05). The present data support the clinically postulated optimal interval for salvage surgery of 6 to 12 weeks.

Keywords: body composition; computed tomography scan; head and neck cancer; head and neck neoplasms; head and neck squamous cell carcinoma; radiochemotherapy; radiomics; radiotherapy; salvage surgery; skeletal muscle; time interval.

Grants and funding

This research received no external funding.