Comparison of Patient-reported Late Treatment Toxicity (LENT-SOMA) with Quality of Life (EORTC QLQ-C30 and QLQ-H&N35) Assessment After Head and Neck Radiotherapy

Purpose: The patient's role in toxicity reporting is increasingly acknowledged but requires the adaptation and validation of toxicity reporting instruments for patient use as most toxicity scales are designed for physician use. Recording of radiotherapy related late toxicity is important and needs to be improved. A patient-scored symptom questionnaire of late treatment effects using LENT-SOMA was compared with a recognised quality of life tool (EORTC QLQ-C30/H&N35).

Materials/methods: LENT-SOMA and EORTC QLQ-C30 patient questionnaires were prospectively completed by 220 head and neck cancer patients over 3 years and 72 completed EORTC QLQ-H&N35 questionnaires at 2 years post-radiotherapy.

Results: Endpoints common to both questionnaires (pain, swallowing, dental pain, dry mouth, opening mouth, analgesics) were matched. Spearman rank correlation coefficients with ρ>0.6 (P<0.001) were obtained for all "matched" scales except for analgesics scale, ρ=0.267 (P<0.05). There was good agreement between LENT-SOMA and EORTC QLQ-H&N35 except for analgesic endpoints. Global quality of life scores correlated negatively with average LENT-SOMA scores (P<0.001). Significant differences in average LENT-SOMA scores between treatment modalities were found. The LENT-SOMA questionnaire has demonstrated a high Cronbach's α value (0.786) indicating good reliability.

Conclusions: LENT-SOMA patient questionnaire results agreed well with those from the EORTC QLQ-H&N35 questionnaire for toxicity items where they could be compared explicitly, particularly for subjective endpoints. Patient-reported late toxicity had a negative impact on quality of life. The LENT-SOMA patient questionnaire is both reliable and sensitive to differences between patients treated with different modalities. A patient-based questionnaire is an important contributor to capturing late radiotherapy effects.