Low-Dose Computed Tomography-Guided Radiofrequency Ablation of Endophytic Recurrent Tumors in a Single Pediatric Kidney: Techniques, Radiation Dose, and Treatment Outcomes.

OBJECTIVE

To assess percutaneous radiofrequency ablation (RFA) techniques, radiation doses, and treatment outcomes for recurrent tumors of a single pediatric kidney.

MATERIALS AND

METHODS

Between August 2019 and January 2025, computed tomography (CT)-guided RFA was performed to treat six recurrent tumors in three children (one boy and two girls; median age at RFA, 12 years and 9 months) who had previously undergone unilateral nephrectomy for sarcoma or Wilm's tumor. All renal tumors (range, 1.6-3.3 cm; median, 2.3 cm) were endophytic and included five Bosniak III cysts and one solid tumor. An internally cooled electrode was used for treatment under general anesthesia. The RFA duration, ablation cycles, electrode repositioning, renal function change, dose-length product (DLP), and oncological outcomes were assessed. A paired t-test was used for statistical analysis.

RESULTS

All tumors were successfully treated in a single session. The median RFA duration was 16 minutes and 40 seconds (range, 7-36 minutes). The median number of RFA cycles and electrode repositions was 4.5 (range, 2-19) and 1 (range, 0-2), respectively. The median estimated glomerular filtration rate before and after RFA were 152.1 mL/min/1.73 m² (range, 107.2-183.4 mL/min/1.73 m²) and 110.7 mL/min/1.73 m² (range, 81.7-162.3 mL/min/1.73 m²), respectively (P = 0.040). The median DLP was 267.1 mGycm (range, 156.7-411.8 mGycm). The technical success and primary effectiveness rates were 100% (6/6). No local tumor progression was detected in any tumors for 1-66 months (median, 34.5 months).

CONCLUSION

Low-dose CT-guided RFA has the potential to treat recurrent endophytic renal tumors and may result in good treatment outcomes.