Radiotherapy Approaches to Reduce Dysphagia Risk
Several radiotherapy-related parameters are associated with the risk that a patient will experience dysphagia, including the total radiation dose delivered, dose fractionation schedules, and treated anatomies.5,11 Not surprisingly, radiation dose to healthy, nontarget swallow function-involved anatomic structures is of particular concern.11
Intensity modulated radiation therapy (IMRT) is increasingly used in the treatment of head and neck cancers because of its ability to better spare or minimize irradiation of nontarget, radiosensitive tissues, reducing the rate of adverse events.10,11 Dysphagia-optimized IMRT (DO-IMRT) is specifically designed to further minimize radiation dose to nontarget, swallowing-involved musculature and nerves to reduce dysphagia risk even more.10
DO-IMRT is a more complex treatment than standard IMRT, and it requires specialized expertise and a more complicated radiotherapy planning process. But a recent report from the phase 3 randomized, controlled DARS trial indicated that DO-IMRT improves patient outcomes.10
The study authors found that DO-IMRT reports patient-reported swallowing function compared to conventional IMRT, leading the study authors to argue that it be “considered a new standard of care for patients receiving radiotherapy for pharyngeal cancers.”10
The study of 112 patients with similar baseline MDADI scores who were randomly assigned 1:1 to receive either DO-IMRT or conventional IMRT found that at 12 months from the initiation of treatment, patients in the DO-IMRT group had significantly better MDADI scores than patients in the control group (mean 77.7 vs 70.6; 95% CI, 0.4-13.9; P =.037).10 (Differences fell to statistical nonsignificance at 18 and 24 months, however.10) The difference in MDADI score averages reflected avoided cases of severe dysphagia. Patients receiving DO-IMRT also reported higher rates of public eating and “normalcy of diet,” but these improvements did not reach statistical significance.10
Grade 3-4 late adverse events included impaired hearing (16% DO-IMRT vs 13% standard IMRT), dry mouth (5% vs 15%), and dysphagia (5% vs 15%).10 No patients in the study died of treatment-related complications.10
“Sparing the constrictor muscles of the pharynx using DO-IMRT significantly improved the MDADI score at 1 year after treatment and beyond,” the authors concluded.10 But DO-IMRT’s narrower target volume margins increase the risk of leaving some tumor cells unirradiated, which would increase the risk of recurrence, they cautioned.10
It is also early days, they acknowledge: the study only examined outcomes for the first 2 years after treatment initiation.10 Additional research is needed to establish long-term safety and effectiveness.
1. Wolf DC. Chapter 82 Dysphagia. In: Walker HK, Hall WD, Hurst JW, eds. Clinical Methods, 3rd edition: The History, Physical, and Laboratory Examinations. Boston, MA: Butterworths; 1990:430-433.
2. Schindler A, Denaro N, Russi EG, et al. Dysphagia in head and neck cancer patients treated with radiotherapy and systemic therapies: literature review and consensus. Cr Rev Oncol Hematol. 2015;96(2):372-384. doi:10.1016/j.critrevonc.2015.06.005
3. Chiu YH, Tseng WH, Ko JY, Wang TG. Radiation-induced swallowing dysfunction in patients with head and neck cancer: a literature review. J Formos Med Assoc. 2022;121(1 Pt 1):3-13. doi:10.1016/j.jfma.2021.06.020
4. Brisson-McKenna M, Jefferson GD, Siddiqui SH, et al. Swallowing function after treatment of laryngeal cancer. Otolaryngol Clin North Am. 2023;56(2):371-388. doi:10.1016/j.otc.2022.11.004
5. Alexidis P, Kolias P, Mentesidou V, et al. Investigating predictive factors of dysphagia and treatment prolongation in patients with oral cavity or oropharyngeal cancer receiving radiation therapy concurrently with chemotherapy. Curr Oncol. 2023;30(5):5168-5178. doi:10.3390/curroncol30050391
6. Petersson K, Finizia C, Tuomi L. Predictors of severe dysphagia following radiotherapy for head and neck cancer. Laryngoscope Investig Otolaryngol. 2021;6(6):1395-1405. doi:10.1002/lio2.676
7. Chen AY, Frankowski R, Bishop-Leone J, et al. The development and validation of a dysphagia-specific quality-of-life questionnaire for patients with head and neck cancer: The M. D. Anderson dysphagia inventory. Arch Otolaryngol Head Neck Surg. 2001;127(7):870-876.
8. Kristensen MB, Isenring E, Brown B. Nutrition and swallowing therapy strategies for patients with head and neck cancer. Nutrition. 2020;69:110548. doi:10.1016/j.nut.2019.06.028
9. Banda KJ, Hsin C, Kao CC, et al. Swallowing exercises for head and neck cancer patients: a systematic review and meta-analysis of randomized clinical trials. Int J Nurs Stud. 2021;114:103827. doi:10.1016/j.ijnurstu.2020.103827
10. Nutting C, Finneran L, Roe J, et al. Dysphagia-optimised intensity-modulated radiotherapy versus standard intensity-modulated radiotherapy in patients with head and neck cancer (DARS): a phase 3, multicentre, randomised, controlled trial. Lancet Oncol. 2023;24(8):868-880. doi:10.1016/S1470-2045(23)00265-6
11. Kannan RA, Ponni A. Dose to swallowing structures and dysphagia in head and neck intensity modulated radiation therapy: a long term prospective analysis. Rep Pract Oncol Radiother. 2019;24(6):654-659. doi:10.1016/j.rpor.2019.09.012
12. Guillen-Sola A, Soler NB, Marco E, Pera-Cegarra O, Foro P. Effects of prophylactic swallowing exercises on dysphagia and quality of life in patients with head and neck cancer receiving (chemo) radiotherapy: the Redyor study, a protocol for a randomized clinical trial. Trials. 2019;20(1):503. doi:10.1186/s13063-019-3587-x
13. Yang W, Nie W, Zhou X, et al. Review of prophylactic swallowing interventions for head and neck cancer. Int J Nurs Stud. 2021;123:104074. doi:10.1016/j.ijnurstu.2021.104074