ImportanceProton radiation therapy (PRT) has reduced radiation-induced toxic effects, such as mucositis and xerostomia, over conventional photon radiation therapy, leading to significantly improved quality of life in patients with head and neck cancers. However, the prevalence of osteoradionecrosis (ORN) of the jaw following PRT in these patients is less clear.ObjectiveTo report the prevalence and clinical characteristics of ORN in patients with oral and oropharyngeal cancer (OOPC) treated with PRT.Design, Setting, and ParticipantsThis case series reports a single-institution experience (Memorial Sloan Kettering Cancer Center, New York, New York) between November 2013 and September 2019 and included 122 radiation therapy–naive patients with OOPC treated with PRT. Data were analyzed from 2013 to 2019.Main Outcomes and MeasuresClinical parameters, including sex, age, comorbidities, tumor histology, concurrent chemotherapy, smoking, comorbidities, and preradiation dental evaluation, were obtained from the medical record. Patients with clinical or radiographic signs of ORN were identified and graded using the adopted modified Glanzmann and Grätz grading system. Characteristics of ORN, such as location, clinical presentation, initial stage at diagnosis, etiology, time to diagnosis, management, and clinical outcome at the last follow-up, were also collected.ResultsOf the 122 patients (mean [SD] age, 63 [13] years; 45 [36.9%] women and 77 [63.1%] men) included in this study, 13 (10.6%) developed ORN following PRT during a median (range) follow-up time of 40.6 (<1-101) months. All patients had spontaneous development of ORN. At the time of initial diagnosis, grade 0, grade 1, grade 2, and grade 3 ORN were seen in 2, 1, 9, and 1 patient, respectively. The posterior ipsilateral mandible within the radiation field that received the full planned PRT dose was the most involved ORN site. At a median (range) follow-up of 13.5 (0.2-58.0) months from the time of ORN diagnosis, complete resolution, stable condition, and progression of ORN were seen in 3, 6, and 4 patients, respectively. The 3-year rates of ORN and death in the total cohort were 5.2% and 21.5%, while the 5-year rates of ORN and death were 11.5% and 34.4%, respectively.Conclusions and RelevanceIn this case series, the prevalence of ORN following PRT was found to be 10.6%, indicating that ORN remains a clinical challenge even in the era of highly conformal PRT. Clinicians treating patients with OOPC with PRT should be mindful of this complication.

Osteoradionecrosis (ORN) of the jaw is one of the most dreaded complications of head and neck radiation therapy. Despite the evolution of radiation treatment modalities, ORN continues to remain a therapeutic challenge and its etiopathogenesis still remains unclear. It is clinically characterized by exposed necrotic bone within the head and neck radiation field. Over the past years, several studies have reported on the definition, staging, incidence, etiology, and management of this oral complication. In this review, we summarize the literature on ORN and discuss our institutional experience and management strategies that aim to predict and mitigate risk for ORN.

Background Although metastatic involvement of bony sites including cranial bones is common in neuroblastoma (NB), mandibular metastases (MM) are uncommon, and specific outcomes have not been reported upon in the modern therapeutic era. Methods In this retrospective study, medical records on patients with MM from NB were reviewed. Statistical analysis was performed using the Kaplan‐Meier method. Results Of 29 patients, nine (31%) had MM at diagnosis, whereas in 20 (69%) MM were first detected at NB relapse at a median time of 26 (6‐89) months from diagnosis. Median maximal diameter of lesions was 3 (range 0.8‐4.9) cm. MM were unilateral in 83% of patients, with ascending ramus (55%) and mandibular body (38%) being the two most common sites. All patients received systemic chemotherapy, and 26 (93%) patients received radiotherapy to MM. At a median follow‐up of 37.3 (24.2‐219.5) months, eight of nine patients with MM at diagnosis did not experience mandibular progressive disease. Eighteen of 20 patients with MM at relapse received therapeutic radiotherapy; objective responses were noted in 78%. Seventy‐two percent (5/18) had not experienced relapse within the radiation field at a median of 12 (2‐276) months postradiotherapy. Dental findings at follow‐up after completion of NB therapy included hypodontia, hypocalcification of enamel, and trismus. Median 3‐year overall survival in patients with relapsed MM was 51 ± 12% months from relapse. Conclusion MM when detected at diagnosis is associated with a prognosis similar to that for other skeletal metastases of NB. Radiotherapy is effective for control of MM detected both at diagnosis and relapse. Significant dental abnormalities posttherapy warrant regular dental evaluations and appropriate intervention.

Intraoral radiation stents (IRS) are prosthetic devices that assist in the effective delivery of radiation to tumor tissues and aim to avoid unnecessary radiation to adjacent healthy tissues, thus limiting postradiotherapy toxicities. They are used to protect or displace vital structures, assist in positioning of the treatment beam for effective administration of radiotherapy, carry a radioactive material, shield healthy tissues of the oral cavity, and/or maintain the desired mouth opening during radiotherapy. With close collaboration between radiation oncologist and oral health care provider, several IRS can be fabricated by the latter for appropriate targeting and delivery of planned radiation dose and optimized treatment results. Modification of these IRS based on individual patient need is recommended to maximize prosthesis utility. The purpose of this review is to discuss the various types of IRS and highlight their clinical utility and benefits in patients receiving radiation therapy in the head and neck cancers.

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