OBJECTIVES: To compare the effects of different irradiators on the establishment of osteoradionecrosis of jaw model (ORNJ) to explore an ideal modeling method. METHODS: A total of 33 adult SD rats were included and randomly divided into three groups according to the radiation equipment, namely, the blank control (CN, 3 rats), group A (linear accelerator irradiation, 15 rats), and group B (small-animal irradiator irradiation, 15 rats). Groups A and B were irradiated with daily fractions of 7, 8, and 9 Gy for 5 days and further divided into three subgroups as follows: group A RESULTS: At 3 weeks after dental extractions, complete gingival healing was found in the regions of dental extractions in groups A CONCLUSIONS Small-animal irradiator irradiation is an ideal device for establishing ORNJ model.
Animals ; Mandible ; Molar ; Osteoradionecrosis/etiology* ; Rats ; Rats, Sprague-Dawley ; X-Ray Microtomography

OBJECTIVETo investigate the preventive effect of low-intensity ultrasound on osteoradionecrosis of jaws (ORNJ).

METHODSTwenty-five canines were randomly divided into experimental group (n=20) and control group (n=5). The canines in experimental group received radiation exposure, and then were randomly subdivided into group A (n=10) and group B (n=10). Control group did not undergo radiotherapy. One month after radiotherapy, the fourth mandibular premolars of all animals were extracted. Group B was immediately treated by low-intensity ultrasound for twenty days, group A and control group did not receive any treatment. Two months after tooth extraction, the formation of ORNJ was determined and the occurrence rate of ORNJ was compared between group A and B. The microstructure of the mandible and changes in microvascular density in group A and B were evaluated and compared with those of control group.

RESULTSAll animals in group B and group A developed ORNJ after prophylactic ultrasound was applied for twenty days. Although the imaging examination of bony density of group A and B were lower than normal animals in control group, bone density in group B was significantly better than group A. Micro-CT showed that the trabecular bone volume fraction, trabecular thickness, bone surface/bone volume and trabecular number in group B were respectively (0.187±0.029)%, (0.160±0.039) µm, (12.536±2.558)/mm, (1.227±0.192)/mm, which were all greater than group A [(0.103±0.014)%, (0.069±0.013) µm, (5.598±0.731)/mm, (0.522±0.064)/mm)] (P<0.05).

CONCLUSIONSAlthough the preventive application of low intensity ultrasound can not prevent the formation of ORNJ, but can significantly improve the symptoms of ORNJ.

Animals ; Bone Density ; radiation effects ; Dogs ; Jaw Diseases ; etiology ; prevention & control ; Mandible ; Osteoradionecrosis ; prevention & control ; Radiation Injuries, Experimental ; Random Allocation ; Tooth Extraction ; Ultrasonic Therapy ; methods ; X-Ray Microtomography

Nasopharyngeal cancer (NPC) is a common malignancy affecting Asian countries, especially the Chinese population. Treatment regimes and results have improved over the years with better overall survival outcome data. Radiotherapy with or without chemotherapy is successful in many patients. Local recurrences are treated with nasopharyngectomy or another course of radiotherapy. The upper cervical spine and skull base can also be involved in NPC patients. Possible aetiologies are osteoradionecrosis, chronic infection and tumour invasion. This article reviews the NPC involvement of C1-2 due to the various pathologies as well as the diagnostic and surgical treatment strategies. Three clinical cases that were surgically treated are discussed along with a review of the current literature.
Adult ; Aged ; Bone Neoplasms ; secondary ; Carcinoma ; Cervical Vertebrae ; drug effects ; radiation effects ; China ; Female ; Humans ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; diagnosis ; surgery ; Osteomyelitis ; diagnosis ; etiology ; surgery ; Osteoradionecrosis ; etiology ; Recurrence ; Spinal Fractures ; etiology ; Treatment Outcome

OBJECTIVETo investigate the incidence of radiation-induced maxillary malignancy after radiotherapy for head and neck cancer.

METHODSA total of 273 patients who suffered from osteoradionecrosis after radiotherapy for head and neck cancer were evaluated. Among them, 6 patients were presented with carcinoma and sarcoma arising from maxillary area after radiotherapy.

RESULTSRadiation-induced maxillary cancers happened at a rate of 2.2% in the patients with osteoradionecrosis. There were no statistically significant differences in age, sex and the time interval between the radiotherapy and the cancer occurrence.

CONCLUSIONSRadiation-induced malignancy after radiotherapy for head and neck cancer is mainly located in maxilla, presenting as squamous cell carcinoma or sarcoma of the maxillary sinus.

Adolescent ; Adult ; Aged ; Female ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Incidence ; Jaw Neoplasms ; etiology ; Male ; Middle Aged ; Neck ; diagnostic imaging ; Neoplasms, Radiation-Induced ; Osteoradionecrosis ; etiology ; Radiography ; Radiotherapy ; adverse effects ; Retrospective Studies ; Young Adult

Postradiation nasopharyngeal necrosis is an important late effect of radiotherapy that affects prognosis in patients with nasopharyngeal carcinoma. In the present study, we reviewed the clinical and imaging features of 67 patients with pathologically diagnosed postradiation nasopharyngeal necrosis who were treated at Sun Yat-sen University Cancer Center between June 2006 and January 2010. Their clinical manifestations, endoscopic findings, and imaging features were analyzed. Early nasopharyngeal necrosis was limited to a local site in the nasopharyngeal region, and the tissue defect was not obvious, whereas deep parapharyngeal ulcer or signs of osteoradionecrosis in the basilar region was observed in serious cases. Those with osteoradionecrosis and/or exposed carotid artery had a high mortality. In conclusion, Postradiation nasopharyngeal necrosis has characteristic magnetic resonance imaging appearances, which associate well with clinical findings, but pathologic examination is essential to make the diagnosis.
Adult ; Aged ; Carcinoma ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; radiotherapy ; Nasopharynx ; pathology ; radiation effects ; Necrosis ; Osteoradionecrosis ; diagnosis ; etiology ; Radiation Injuries ; diagnosis ; etiology ; Radiotherapy, Intensity-Modulated ; adverse effects