Risk profile for osteoradionecrosis of the mandible in the IMRT era

Abstract

BackgroundThe risk for osteoradionecrosis (ORN) of the mandible is positively related to bone volume exposed to > ~ 60 Gy. We hypothesized that in combined treatment, surgery may also be a risk factor.Patients and methodsThe impact of mandibular surgery on ORN in locally disease-free IMRT cohorts was retrospectively analyzed.ResultsBetween October 2002 and October 2013, 531 of 715 patients with oral cavity cancer (OCC), mesopharyngeal cancer (MC), or salivary gland tumor were treated with the mandible bone exposed to ~ > 60 Gy (mean follow-up, 38 months; 7–143 months). Of the 531 patients, 36 developed ORN (7 %; 1.5 % with grade 3–4). The ORN rate in definitive IMRT MC (16/227) and in postoperative IMRT OCC patients with no mandibular surgery (3/46) was 7 % each; in OCC patients with mandibular surgery the rate was 29 % (15/60, p = 0.002). Marginal or periosteal bone resection was found to be a high risk factor (39 %, vs. 7 % followed by segmental or no resection, p < 0.0001).ConclusionMarginal or periosteal bone resection of the mandible was identified as the highest ORN risk factor in our IMRT cohort.

The prevalence and risk factors associated with osteoradionecrosis of the jaw in oral and oropharyngeal cancer patients treated with intensity-modulated radiation therapy (IMRT): The Memorial Sloan Kettering Cancer Center experience

“…In a similar study from our institution, only 2 out of 168 patients developed ORN, with a median follow-up of 37.4 months [14]. However, recent studies with larger patient sample have reported higher prevalence of ORN; 21/334 (6.3%) and 36/531 (6.8%) patients developing ORN in patients treated with IMRT at a median follow-up of 31 months in patients treated for T1/T2 and mean follow-up of 38 months, respectively [23, 24]. …”

Outcomes of oral cavity cancer patients treated with surgery followed by postoperative intensity modulated radiation therapy

“…This is consistent with other recent reports exploring IMRT for oral cavity cancers, or the incidence of ORN in patients treated with IMRT for head and neck cancers. [19, 20] Studer et al recently reported 17% incidence of ORN in patients with oral cavity cancers treated with postoperative IMRT who received >60 Gy to the mandible. [19] A recent SEER medicare analysis of jaw complications in patients treated for oral cancers showed that patients treated with non-IMRT had 17% even rate compared to 14% in patients treated with IMRT.…”

Comparison of mean radiation dose and dosimetric distribution to tooth-bearing regions of the mandible associated with proton beam radiation therapy and intensity-modulated radiation therapy for ipsilateral head and neck tumor

“…Osteoradionecrosis (ORN) remains a potentially serious complication following radiotherapy, even in the era of IMRT 8, 10, 22 . ORN is defined as an area of exposed bone greater than 1 cm in size in an area previously irradiated that failed to heal over a period of 3–6 months, and may require resection of the necrotic segment(s) of the jaw.…”

“…Reported incidence of ORN ranges from 6.3–6.8% of patients with oral and oropharyngeal cancer treated with IMRT. 8, 10 . High radiation dose and jaw trauma due to dental extraction remain major risk factors for this complication 10, 23–26 .…”

“…8, 10 . High radiation dose and jaw trauma due to dental extraction remain major risk factors for this complication 10, 23–26 . Radiation doses >60 Gy to the bone is significantly linked to the risk of developing ORN and mean doses > 40Gy were predictive of increased subsequent dental events 25, 27 .…”