In vivo dosimetry in head and neck cancer radiotherapy patients using an intraoral stent: prospective cohort.

OBJECTIVES

To evaluate the radiation dose in the oral cavity structures (through in vivo dosimetry and treatment planning system) of head and neck cancer patients; and secondarily, evaluate sialometry and oral mucositis.

STUDY

DESIGN

This is a prospective cohort study with patients over 18 years old, diagnosed with oral cavity and major salivary glands cancer, treated with radiotherapy. Group A patients used an intraoral stent (n = 14), and those in Group B (n = 14) did not. In Group A, in vivo dosimetry was performed by positioning 2 thermoluminescent dosimeters in the intraoral stent; unstimulated and stimulated salivary flow were measured; and oral mucositis was evaluated.

RESULTS

In vivo dosimetry demonstrated higher doses in the tumoral area in comparison with the opposite tumor area (p < .001). The planning system predicted doses in nontumor area were lower in Group A. Unstimulated sialometry was higher in Group A in the intermediate and final sessions (p < .05), and hyposalivation was more frequent in Group B (p = .015). No statistically significant differences were observed between the groups regarding the maximum grade and duration of oral mucositis (p = .499; and p = .466, respectively).

CONCLUSION

The intraoral stent was associated with opposite tumor area lower doses, measured using in vivo dosimetry, the first time this method was applied in studies on this device. Individuals treated with the intraoral stent presented higher salivary flows during and after radiotherapy.