Purpose: In the light of the rapid growth of intensity modulated proton therapy (IMPT) use in head and neck cancers over the past years, value-based assessment of proton beam therapy, including patient-reported quality of life (QoL) outcomes, is critical. There is currently a lack of data on QoL outcomes after proton beam therapy. The purpose of this study was to report QoL outcomes from the Functional Assessment of Cancer Therapy-Head and Neck (FACT-HN) questionnaire of patients with oropharynx cancer treated with IMPT in the context of first course irradiation.
Material and methods: Patients treated with loco-regional IMPT for head and neck cancer between 2011 and 2018 were enrolled in this prospective study. In the current analysis, patients with oropharynx squamous cell cancer (OPSCC), treated with curative intent at MD Anderson Cancer Center, and having at least one post-treatment visit were included. Patients with non-SCC histology, distant metastasis or patients undergoing re-irradiation were excluded. FACT-H&N scores were measured at baseline, at weekly visit during IMPT as well as at each follow-up visit up to 4 years after treatment. A paired t-test was used to assess the changes from baseline at each visit. Disease free survival was estimated using the Kaplan and Meier method.
Results: Fifty-seven patients met the inclusion criteria. Median age was 60 year-old (range: 41-84), 86% of patients were male, 91% had human papilloma associated disease, 49% were never smoker and 46% had quit smoking. In total, 28% received induction chemotherapy, 68% had concurrent chemotherapy, 7% had robotic surgery, and only 23% had single modality PBT. As per AJCC 8th Ed., 61%, 19%, 11%, 7% and 2% of patients had stage I, II, III, IVA and IVB, respectively. Median follow-up was 2.8 years (95% CI= 2.2-3.5 years). The 1- and 2-year DFS were 95% and 84%, respectively. The mean FACT-General (G), FACT-Total and FACT-Trial Outcome Index (TOI) score changes were statistically and clinically significant compared to baseline from week 3 of treatment up to week 2 post-treatment. Nadir was reached at week 6 of treatment for all scores, with maximum scores dropping by 14, 23 and 23 points compared to baseline for FACT-G, FACT-Total and FACT-TOI, respectively. Similarly, subdomain scores of physical well-being, functional well-being and head and neck additional concerns decreased from baseline during treatment, reaching a nadir at week 6 of treatment, and rapidly returning back to baseline at week 4 post-treatment. There were no difference in emotional well-being and social well-being subdomain scores across time.
Conclusion: IMPT for OPSCC is associated with favourable QoL outcomes as assessed by FACT-HN. There was acute decline in summary scores, as well as physical well-being, functional well-being and additional head and neck concerns subdomain scores during IMPT, followed by rapid return to baseline at 4 weeks post-treatment.