Purpose: While modern radiation therapy has achieved improved tumor control with advanced beam delivery and image-guidance technologies, normal tissue toxicity remains a grave concern in the clinic. This work aimed to develop a personal organ dose archive (PODA) system and demonstrate its potential use in the clinic to improve patient safety by tracking organ doses from both treatment delivery and imaging guidance procedures.
Methods: A prototype of PODA, which consisted of a patient database, a Monte Carlo dose engine, and a dose report and early warning module, was developed. A group of four pediatric patients was retrospectively registered in PODA in order to track their accumulated organ doses during radiotherapy. These patients have been previously identified to bear high imaging doses out of 4,832 patients who have received image-guided radiotherapy at our institution. Follow-up histories of 4-7 years were reviewed from the electronic medical record system to identify normal tissue toxicity after radiotherapy.
Results: Imaging doses to the organs-at-risk (OARs) for the group of 4 pediatric patients ranged between 0.4-1.8 Gy depending on imaging modality, imaging frequency, patient size, and relative location of the organ in the body. The inclusion of imaging dose pushed total dose towards OAR dose tolerance to varying extent. In two cases in the cochlea and the brain, the differences between total doses and tolerances were less than 3%. In another two cases, total doses to the lens and the brain exceeded OAR tolerances by 17% and 4%, respectively. Notably, three children out of this group developed late effects related to those organs.
Conclusion: A prototype of PODA has been developed, with preliminary results indicating a correlation between high cumulative doses to OARs and normal tissue complications. More evaluation is underway to ensure that PODA can serve as an independent safety assurance for patients undergoing radiotherapy.
Not Applicable / None Entered.