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SIR 2025
Pediatric Interventions
Traditional Poster
Usama Anwar, MBBS (he/him/his)
Research Fellow
Boston Children's Hospital, Department of Interventional Radiology, United States
Gulraiz Chaudry, MD
Pediatric Interventional Radiologist
Boston Children's Hospital, United States
Horacio M. Padua, Jr., MD
Pediatric Interventional Radiologist
Children's Hospital Boston, United States
Raja Shaikh, MBBS
Pediatric Interventional Radiologist
Boston Children's Hospital, United States
To report MRI findings of changes seen in aneurysmal bone cysts (ABC) after percutaneous cryoablation treatment.
Materials and Methods:
This study retrospectively reviewed 21 aneurysmal bone cysts patients treated with cryoablation at a tertiary pediatric hospital between March 2017 and December 2023. The pre-treatment and serial post-treatment MRIs were reviewed. Several pre-determined MRI features of the lesion were evaluated. The evolution of post-treatment characteristics along with the timeline for each of these changes was recorded. Descriptive analyses were performed using IBM Statistical Package for Social Sciences SPSS v 29.0.0.0 (241).
Results:
The study evaluated 21 patients (14.4 years ± 4.7, 11 females). Early post-cryoablation MRI changes include paradoxical increase in the perilesional edema and enhancement, which appear on average 7.7 months (Range: 1-16 months) after the initial cryoablation. This is followed by gradual resolution of cystic areas at 12.4 months (Range: 1-28 months) after the initial treatment. Later changes include improved cortical integrity at 11.3 months (Range: 1-35 months), edema resolution at 11.9 months (Range: 1-38 months), and greater than 75% lesion replacement with organized fibrous tissue by 15 months (Range: 1-28 months). Lesion volume decreased from an average pre-treatment volume of 106.7 cm³ (range: 2.21 - 450.96 cm³) to 35.1 cm³ (range: 0.46 - 160.29 cm³) at final follow-up MRI. Bone remodeling and noticeable ossification are latest to appear in the sequence of post treatment changes. During post treatment evolution there is intralesional enhancement of the fibrous tissue, which should not be mistaken for recurrence, or persistence of ABC.
Conclusion:
This study details the expected MRI changes and their respective timeline for evolution following image guided percutaneous cryoablation in aneurysmal bone cysts. These features can be included in effective response assessment to the treatment to help guide further management in patients with aneurysmal bone cysts.