In a single-institution study reported in the Journal of Clinical Oncology, Watson et al identified risk factors for osteoradionecrosis of the jaw and developed a classification system for the condition in patients receiving radiation therapy for head and neck cancer.
Study Details
The study involved 2,732 consecutive patents with head and neck cancer treated with curative-intent intensity-modulated radiation therapy (IMRT; ≥ 45 Gy) from 2011 to 2017 at Princess Margaret Cancer Centre in Toronto.
Key Findings
Osteoradionecrosis was detected in 219 (8%) of 2,732 consecutive patients.
Factors significantly associated with a higher risk of osteoradionecrosis were primary oral cavity cancer (risk score coefficient [RSC] = 1.7), primary oropharyngeal cancer (RSC = 1.4), an IMRT dose of ≥ 60 Gy (RSC = 1.3), current or former smoking (RSC = 0.4), and stage III to IV periodontal condition (RSC = 0.4). The high-risk group had a sum of risk score coefficient values of ≥ 3.5; the low-risk group had a sum of < 3.5. Osteoradionecrosis occurred in 12.7% of high-risk patients vs 3.1% of low-risk patients (P < .001), with the model having a receiver operating characteristic of area under the cure of 0.71.
According to the investigators, “Existing osteoradionecrosis systems overclassified serious osteoradionecrosis events [ie, jaw fracture or requiring jaw resection] and failed to recognize maxillary osteoradionecrosis. A novel osteoradionecrosis classification system, ClinRad, was proposed on the basis of vertical extent of bone necrosis and presence/absence of exposed bone/fistula. The system detected serious osteoradionecrosis events in 5.7% of patients and statistically outperformed existing systems.” The ClinRad system demonstrated good concordance in Cox modeling, yielding the highest concordance statistic across all systems (area under the curve = 0.73).
The investigators concluded, “We identified risk factors for osteoradionecrosis and proposed a novel osteoradionecrosis classification system on the basis of vertical extent of bone necrosis and presence/absence of exposed bone/fistula. It outperformed existing systems in depicting the seriousness of osteoradionecrosis and may facilitate clinical care and clinical trials.”
Erin E. Watson, DMD, MSHc, of the Department of Dental Oncology, Princess Margaret Cancer Centre, Toronto, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.
