Bone and gallium scans in postradiotherapy osteonecrosis of the jaw

Abstract

The role of radiographic and nuclear imaging in evaluation of postradiotherapy osteonecrosis of the jaw was studied. Patients who had received imaging at diagnosis and following hyperbaric oxygen therapy were studied. Radiographic changes did not correlate with the clinical status of patients. All bone scans were abnormal at the time of diagnosis of osteonecrosis, but remained abnormal following changes in the clinical status of patients. Thus, the bone scan may aid in the detection of osteonecrosis. Gallium uptake did not aid i diagnosis, but did correlate with clinical findings following treatment. Persisting positive gallium scans may indicate the need for surgery following hyperbaric oxygen therapy.

Bilateral osteoradionecrosis of the jaw – A rare case report

“…ORN typically advances during the first 6-12 months after RT. [4,17,21,[23][24][25][26][27][28] Berger and Symington reported two late presentations, one 45 years after a radium implant, and another 38 years after external beam treatment. [28] Although there are various risk factors, but the dental extractions immediately before or after RT are considered to be the main triggering factor of osteoradionecrosis.…”

“…[4,5,29] The first method to prevent either future tooth extractions or ORN should occur previously to the beginning of the oncotherapy, by performing an adaptation of the oral environment to decrease the infection. [1,3,6,10,23] In this case, this adjustment was carried out, however, caries eventually evolved, largely compromising the tooth structure and oral health. Another important factor for extracting questionable teeth is a lack of motivation which may lead poor oral hygiene required for dental maintenance, which may cause infections, increasing, thus, the risk of ORN.…”

Near infrared spectroscopy: A diagnostic tool to evaluate effects of radiotherapy in the mandible?

“…Thus, the conditions necessary for gallium uptake may not be present and it may not be of diagnostic value for osteoradionecrosis. However, gallium scans did correlate with clinical findings following treatment, suggesting that persisting positive gallium scans may indicate the need for surgery following conservative treatment [18].…”

“…Although radiographic images are extensively used, they require a substantial alteration in mineral content and extensive involvement of the bone, which only occurs in later stages, and therefore they underestimate the extent of radiation-damaged bone, and do not correlate with the clinical status of patients [17,18]. Computer tomography (CT) scans have similar limitations as traditional radiographs for the mandible or maxilla, but can be helpful in temporal bone osteoradionecrosis [33].…”

“…But an increased uptake of 99m Tc-MDP has been seen at sites of radiotherapy (showing as 'hot' or 'black' spots on the image) during and immediately following treatment [1,40]. Osteoradionecrosis is also marked by an increased rate of uptake and total uptake of 99m Tc-MDP relative to adjacent bone [18,35]. Furthermore the scans remained altered even after successful treatment.…”