In the case of patients exposed to large amounts of radiation due to radiation therapy, such as cancer patients, special attention should be paid to the risk of implant failure.
A research team at Yonsei University, including Prof. Inho Cha (Oral and Maxillofacial Surgery, Yonsei University), revealed this as a result of examining the prognosis and risk factors of patients who had implants placed following receiving radiation therapy for head and neck cancer. This research paper was published in the August issue of the international journal ‘Head & Neck (IF: 3.821)’.
The relationship between implants and radiation exposure has been reported since the early 2000s.
Therefore, the research team evaluated 90 implants placed in 27 patients who received radiation therapy for head and neck cancer from 2008 to 2018.
The most common type of radiation therapy was intensity-controlled radiation therapy (IMRT) (23 patients, 85.2%), followed by concurrent chemoradiotherapy (44.4% (12 patients)) and 3D stereolithography. (3D-CRT) was 14.8% (4 patients).
As a result of the analysis, the radiation dose exposure standard that judged the success or failure of the implant was 38 gray (Gy).
If the radiation exposure was less than 38 gray, the implant survival rate for 3 years was 100%, but if the radiation exposure was 38 gray or more, the survival rate dropped to 44.2%. In addition, when the radiation exposure dose was less than 50 gray, the implant survival rate was 92%, but when the radiation exposure was 50 gray or more, the survival rate decreased significantly to 40.9%.
In particular, the timing of radiation therapy also had an effect. Patients who received radiation therapy before implant placement had a higher risk of implant failure than patients who received radiation therapy following placement.
“Exposure to high doses of radiation is highly likely to cause vascular damage, connective tissue fibrosis, and muscle and epithelial damage, leading to radioactive osteonecrosis. In order to prevent osteonecrosis, if possible, implant placement should be performed prior to receiving radiation therapy.
