Computer-navigated, stereotactic navigation for percutaneous radiofrequency ablation of osteoid osteomas: dose comparison and procedure times.

Purpose Treatment of medication-refractory osteoid osteoma is typically performed with minimally-invasive percutaneous techniques, such as radiofrequency ablation. Given the typically young age of the population of patients being treated, we sought to assess whether using a 3D CT guidance system reduces the number of required probe repositionings and the number of required CTs to validate probe positioning in order to reduce the radiation dosage to the patient. Methods We retrospectively reviewed the records of 19 patients who underwent procedures at our clinic amounting to a total of 27 ablations between 2012 and 2022. At the time of each procedure, the operating physician made the decision whether or not to use stereotactic navigation assistance. We analyzed the data using a Bayesian approach to elucidate possible differences between procedures conducted with or without navigation. Results Our results showed a statistically and clinically-significant administration of, on average, 200 mGy*cm greater radiation dosage to the patient when stereotactic navigation was used to guide RFA probe placement for ablation of osteoid osteomas compared with not using navigation assistance. There was a trend towards requiring one fewer probe repositioning with navigation assistance, however this was not statistically conclusive. There was no difference in the time required to achieve the target probe placement or in total procedure duration whether stereotactic navigation was used or not. Conclusion When utilizing a 3D-guided stereotactic navigation system, there is likely a learning phase before the potential benefits of such a system are realized. Additional radiation administration to the patient may result from the operator learning to properly use and trust the system. In our case, the data also likely reflect a bias in operator choice to use the navigation system when the lesions are more difficult to correctly target or multiple ablation positions are necessary, while choosing conventional imaging assistance for easily targetable tumors, which may conceal some of the benefit of using the navigation system.