Salivary gland hypofunction and xerostomia are induced by radiotherapy in the head and neck region depending on the cumulative radiation dose to the gland tissue. Treatment focus should be on optimized/new approaches to further reduce the dose to the parotids, and particularly submandibular and minor salivary glands, as these glands are major contributors to moistening of oral tissues. Other cancer treatments also induce salivary gland hypofunction, although to a lesser severity, and in the case of chemotherapy and immunotherapy, the adverse effect is temporary. Fields of sparse literature included pediatric cancer populations, cancer chemotherapy, radioactive iodine treatment, total body irradiation/hematopoietic stem cell transplantation, and immunotherapy.

Purpose-To assess the prevalence and the dosimetric and clinical predictors of mandibular osteoradionecrosis (ORN) in patients with head and neck (HN) cancer who underwent pre-therapy dental evaluation and prophylactic treatment according to a uniform policy and were treated with intensity modulated radiation therapy (IMRT). [1996][1997][1998][1999][2000][2001][2002][2003][2004][2005] all patients with HN cancer treated with parotid gland sparing IMRT in prospective studies underwent dental examination and prophylactic treatment according to a uniform policy including extractions of high-risk, periodontally involved and nonrestorable teeth in parts of the mandible expected to receive high doses, fluoride supplements, and guards aiming to reduce electron backscatter off metal teeth restorations. The IMRT plans included dose constraints for the maximal mandibular doses and reduced mean parotid gland and non-involved oral cavity doses. Retrospective analysis of grade ≥2 (clinical) ORN was performed. Methods and Materials-BetweenResults-176 patients had minimal follow-up 6 months. Thirty-one (17%) had teeth extractions prior to radiation and 13 (7%) post-radiation. 75% and 50% of the patients received at least 65Gy and 70Gy to ≥ 1% of the mandibular volumes, respectively. Fall-off across the mandible characterized the dose distributions: the average gradient (in the axial plane containing the maximal mandibular dose) was 11 Gy (range 1-27Gy, median 8Gy). At median 34 months follow-up there were no cases of ORN (95% CI, 0; 2%).Conclusions-The use of a strict prophylactic dental care policy and IMRT resulted in no case of clinical ORN. In addition to the dosimetric advantages offered by IMRT, meticulous dental prophylactic care is likely an essential factor in reducing ORN risk.

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There is evidence that salivary gland hypofunction and xerostomia induced by cancer therapies can be prevented or symptoms be minimized to some degree, depending on the type of cancer treatment. Management guideline recommendations are provided for IMRT, amifostine, muscarinic agonist stimulation, oral mucosal lubricants, acupuncture, and submandibular gland transfer. Fields of sparse literature identified included effects of gustatory and masticatory stimulation, specific oral mucosal lubricant formulas, submandibular gland transfer, acupuncture, hyperbaric oxygen treatment, management strategies in pediatric cancer populations, and the economic consequences of salivary gland hypofunction and xerostomia.

Purpose After conventional radiotherapy for head and neck cancer, xerostomia has traditionally been the major effector of patient-reported quality of life (QOL), and recent publications suggest that dysphagia has an even stronger effect. We hypothesized that IMRT aiming to spare the salivary glands and swallowing structures reduced, or eliminated, the effects of these toxicities on QOL. Methods and Materials Prospective longitudinal study: 72 patients with Stage III-IV oropharyngeal cancer treated uniformly with definitive chemo-IMRT sparing the salivary glands and swallowing structures. Overall QOL was assessed by summary scores of the Head Neck QOL (HNQOL) and University of Washington QOL (UWQOL) questionnaires, as well as HNQOL “Overall Bother” question. QOL, observer-rated toxicities (CTCAE v2), and objective evaluations (videofluoroscopy assessing dysphagia and saliva flow rates assessing xerostomia) were recorded pre-therapy through 2 years post-therapy. Correlations between toxicities/objective evaluations and overall QOL were assessed using longitudinal repeated measures of analysis and Pearson correlations. Results All observer-rated toxicities and QOL scores worsened 1-3 months after therapy and improved through 12 months, with minor further improvements through 24 months. At 12 months, dysphagia grades 0-1, 2, and 3, were observed in 95%, 4%, and 1% of patients, respectively. Using all post-therapy observations, observer-rated dysphagia was highly correlated with all overall QOL measures (p<0.0001), while xerostomia, mucosal, and voice toxicities were significantly correlated with some, but not all, overall QOL measures, with lower correlation coefficients than dysphagia. Late overall QOL (≥6 or ≥12 months post-therapy) was primarily associated with observer-rated dysphagia, and to a lesser extent with xerostomia. Videofluoroscopy scores, but not salivary flows, were significantly correlated with some of the overall QOL measures. Conclusion After chemo-IMRT, while late dysphagia was on average mild, it was still the major correlate of QOL. Further efforts to reduce swallowing dysfunction are likely to yield additional gains in QOL.