Main Session
Sep 29
PQA 07 - Head and Neck Cancer, Lung Cancer/Thoracic Malignancies, and Nursing and Supportive Care

3618 - Prospective Study of Radiation Dose to Dysphagia-Aspiration Related Structures and Patient-Reported Swallowing Outcomes in Head and Neck Squamous Cell Carcinoma

03:45pm - 05:00pm ET
Poster Hall - Exhibit Hall A
Screen: 14
POSTER

Presenter(s)

Kanika Sharma, MD, MBBS, PCHM Headshot
Kanika Sharma, MD, MBBS, PCHM - Narayana Health, Delhi, MN

J. Prem1, K. S. Sharma2, P. Khullar3, A. Tanwar1, M. Himthani4, J. Mohapatra3, A. Sharma3, S. Jain3, and R. Agarwal5; 1Dharamshila Narayana Superspeciality Hospital, Delhi, India, 2Dharamshila Narayana Super Speciality Hospital, Delhi, India, 3Dharamshila Narayana Super Speciality Hospital, DELHI, India, 4Dharamshila Narayana Superspecialty Hospital, Delhi, India, 5dharamshila Narayana Superspeciality Hospital, delhi, India

Purpose/Objective(s):

Radiation-induced dysphagia significantly impacts quality of life in head and neck cancer survivors. Dysphagia-aspiration related structures (DARS) are critical organs at risk, but prospective longitudinal data defining dose–response relationships and clinically relevant dose thresholds remain limited. This prospective study evaluated the association between radiation dose to DARS and swallowing function using validated patient-reported outcomes, and identified critical periods and dose thresholds for dysphagia development.

Materials/Methods:

Forty-two patients with stage I–IVB head and neck squamous cell carcinoma underwent definitive or adjuvant intensity-modulated radiotherapy. DARS including pharyngeal constrictor muscles, epiglottis, and base of tongue were contoured. Mean dose (Dmean) and maximum dose (Dmax) were extracted from treatment plans. Swallowing function was assessed using MD Anderson Dysphagia Inventory composite scores at baseline, every 5 fractions during radiotherapy, and at 1 week, 1 month, and 3 months post-treatment. Statistical analysis included Pearson correlation, linear regression, paired t-tests, and segmented regression.

Results:

Mean MDADI composite scores declined from 66.0 ± 5.9 pre-RT to 44.1 ± 8.8 at fraction 35 (p < 0.001). The steepest deterioration occurred between fractions 5 and 15 (p < 0.001 for fractions 5 vs 10; p = 0.003 for fractions 10 vs 15), after which scores plateaued. Dmean demonstrated moderate negative correlation with composite scores (r = -0.59, p < 0.001), with a 4.6-point decrease per 10 Gy. Dmax showed stronger correlation (r = -0.61, p < 0.001), with a 3.8-point decrease per 10 Gy, explaining 37.5% of variability versus 34.7% for Dmean. Segmented regression identified dose thresholds at 55–57.5 Gy beyond which dysphagia severity significantly increased (p < 0.01). Post-treatment recovery was observed, with scores improving to 52.0 ± 14.2 at 2 weeks and 65.0 ± 13.2 at 3 months. Three postoperative patients developed aspiration pneumonia.

Conclusion:

Radiation dose to DARS demonstrates a clear dose-dependent association with dysphagia severity, with Dmax showing stronger predictive value than Dmean. The early decline observed between fractions 5 and 15 represents a potential window for intervention. Dose thresholds at 55–57.5 Gy were associated with significantly increased dysphagia severity. Substantial recovery was observed by 3 months post-treatment, although inter-patient variability persisted. These findings support optimization of DARS dose constraints to preserve swallowing function in head and neck cancer patients.