Clinical Diagnostic Imaging Study of Osteoradionecrosis of the Jaw: A Retrospective Study

Abstract

Radiation therapy (RT) plays a significant role in the management of head and neck malignancies. This study aimed to review the clinical symptoms and various imaging findings of osteoradionecrosis (ORN) and provide a clinical perspective on the development of ORN. The retrospective cohort was composed of 57 sites in 54 patients who had a history of RT and suspected ORN and 48 sites in 45 patients who were confirmed to have ORN. Image analyses included computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET)/CT, bone scintigraphy, and single-photon emission CT (SPECT). The irradiated tissue was damaged by RT, and the extent of damage was correlated with clinical symptoms. The bone marrow showed sclerotic changes and the devitalized bone showed bone resorption after invasive stimulation. Chronic trismus and pathological fracture are considered severe conditions, typically occurring in the last stage of ORN. Furthermore, neurological symptoms were an important sign of tumor recurrence, since diagnostic imaging was difficult. The possible treatment options vary depending on the stage of ORN. We speculate that bone sclerosis reactions and bone resorption are sequential reactions that seem to be protective measures of the bone to radiation injury.

Challenges in the Radiological Diagnosis of Osteoradionecrosis of the Jaw in Head and Neck Cancer Patients

“…Diagnostic imaging studies revealed long-term RT-related bone marrow deterioration on MRI, and sclerotic changes in 82% of the bone marrow on CT. In the same study, PET/CT and SPECT were confirmed to be beneficial in the diagnosis of ORNJ, with PET/CT revealing the involvement of the tissue surrounding the affected bone and SPECT recognizing ORNJ' s tracer uptake (101).…”

“…The ORNJ genesis process includes hypovascularization, hypoxia, and fibrosis that are brought on by abnormal bone marrow changes in addition to bone sclerosis brought on by RT-induced damage (7,44,88,101). Additionally, fibrosis and inflammation in the nearby masticatory muscles may cause one of the signs of ORNJ, trismus (111).…”

“…Furthermore, it could be challenging to distinguish between the involvement of the soft tissues and the bones when osteomyelitis is present. In cases where it is difficult to make an exact distinction, incisional biopsy is recommended for a definitive diagnosis of tumor recurrence (100,101). However, the biopsy procedure must be as minimally invasive as possible to avoid the formation of a fistula.…”

Factors Associated with Treatment Outcomes and Pathological Features in Patients with Osteoradionecrosis: A Retrospective Study

“…CT imaging is indispensable for diagnosis and treatment planning for patients with ORN [ 5 , 15 ]. As irradiated bone is in a chronic inflammatory state, osteolysis, osteosclerosis, and sequestration are commonly observed [ 14 , 37 , 38 ]. Cortical disruption and/or disorganization of the trabeculation characterize osteolysis.…”

“…Osteosclerosis is characterized by increased bone density. Miyamoto et al described the mechanism by which radiation damage affects osteocytes and activates osteoblasts, leading to reactive bone consolidation, particularly in the cancellous bone area [ 38 ]. The inhibition and destruction of both osteoblastic and osteoclastic mechanisms also cause sequestration.…”