International Journal of Radiation Oncology*Biology*Physics
Clinical InvestigationOsteoradionecrosis and Radiation Dose to the Mandible in Patients With Oropharyngeal Cancer
Introduction
Osteoradionecrosis (ORN) is a potentially debilitating complication of radiation therapy for patients with head-and-neck cancers. Possible risk factors include age, sex, medical comorbidities, primary tumor site and stage, tumor location in relation to the mandible, dentition status, types of treatment and technique (external beam radiation, brachytherapy, surgery, chemotherapy, or combination therapy), radiation dose, dental extraction before and after radiation or surgery, smoking, and alcohol 1, 2, 3.
In a study of head-and-neck cancer patients treated with parotid-sparing intensity modulated radiation therapy (IMRT) by Ben-David et al, prophylactic dental care and the use of IMRT resulted in no case of grade ≥2 ORN (1). Similar results were supported by other studies 4, 5, 6. Currently, the most commonly recommended dose constraint to the mandible is a maximum of 70 Gy (3).
Given the relatively low incidence of ORN, the number of ORN cases included in published literature is small. There is no multivariate analysis comparing mandibular radiation doses between ORN and ORN-free patients, as far as we are aware. This study examined the association between radiation doses to the mandible and ORN in patients treated with 3-dimensional (3D) conformal radiation therapy or IMRT. We compared mandibular dose distributions in ORN and ORN-free patients to establish a clinically relevant mandibular dose constraint. We also analyzed multiple possible risk factors associated with ORN.
Section snippets
Patient selection
This study included 402 patients with newly diagnosed oropharyngeal cancer, having clinically staged T1 or T2 disease and treated between January 2000 and October 2008. They were part of a prospective molecular epidemiologic study of genetic susceptibility to head-and-neck cancers. The Institutional Review Board at our institution approved this study, and informed consent was obtained for each patient. We selected only those with clinical stage T1-T2 disease and those treated with definitive
Characteristics of all patients
The median follow-up time was 31 months (range, 1-120 months); ORN developed in 30 of the 402 patients (7.5%). The median time to develop ORN was 8 months (range, 0-71 months). Ten of the 30 ORN patients had exposed bone and received conservative management (grade 1), 9 had minor debridement (sequestrectomy, grade 2), 5 required hyperbaric oxygen (grade 3), and 6 patients had grade 4 ORN that required major surgery (including mandibulectomy or hemimandibulectomy, removal of necrotic bone from
Discussion
In this observational study of patients with stage T1-T2 oropharyngeal cancer, ORN developed in 30 of 402 patients (7.5%) during a median follow-up time of 31 months, and 6 (1.5%) eventually needed major surgical intervention. A fairly representative series on the incidence of ORN was reported by Reuther et al; the authors described a 8.2% rate of ORN in 830 patients during a 30-year period (8). This incidence seems consistent with our findings. In general, the incidence of ORN described in the
Conclusion
The overall ORN occurrence was relatively low among oropharyngeal cancer patients receiving radiation therapy, and most ORN patients could be treated conservatively. ORN was associated with the use of tobacco and alcohol and occurred more frequently in patients receiving higher prescription doses (≥70 Gy) to the primary cancer site. The dose-volume factor for the mandible seemed to play a significant role: the range between V50 and V60 saw the most significant differences between the ORN group
References (20)
- et al.
Lack of osteoradionecrosis of the mandible after intensity-modulated radiotherapy for head and neck cancer: likely contributions of both dental care and improved dose distributions
Int J Radiat Oncol Biol Phys
(2007) - et al.
Implications of radiation dosimetry of the mandible in patients with carcinomas of the oral cavity and nasopharynx treated with intensity modulated radiation therapy
Int J Oral Maxillofac Surg
(2005) - et al.
Correlation of osteoradionecrosis and dental events with dosimetric parameters in intensity-modulated radiation therapy for head-and-neck cancer
Int J Radiat Oncol Biol Phys
(2011) - et al.
Disease-control rates following intensity-modulated radiation therapy for small primary oropharyngeal carcinoma
Int J Radiat Oncol Biol Phys
(2007) - et al.
Osteoradionecrosis of the jaws as a side effect of radiotherapy of head and neck tumour patients: a report of a thirty year retrospective review
Int J Oral Maxillofac Surg
(2003) - et al.
Hyperbaric oxygen therapy in the treatment of radio-induced lesions in normal tissues: a literature review
Radiother Oncol
(2004) Osteoradionecrosis prevention myths
Int J Radiat Oncol Biol Phys
(2006)- et al.
Risk factors and dose-effect relationship for mandibular osteoradionecrosis in oral and oropharyngeal cancer patients
Int J Radiat Oncol Biol Phys
(2009) - et al.
The relationship between dental disease and radiation necrosis of the mandible
Oral Surg Oral Med Oral Pathol
(1980) - et al.
Radiation necrosis of the mandible: a 10 year study. Part I. Factors influencing the onset of necrosis
Int J Radiat Oncol Biol Phys
(1980)
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Conflict of interest: none.