Multimodality Image-Guided Cryoablation for Inoperable Tumor-Induced Osteomalacia

Area of Science:

• Endocrinology
• Oncology
• Nephrology
• Bone Metabolism

Background:

• Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by FGF23-secreting phosphaturic mesenchymal tumors (PMTs).
• Surgical resection is curative but often precluded by patient comorbidities or tumor location.
• Alternative treatments are needed for patients unsuitable for surgery.

Purpose of the Study:

• To evaluate the efficacy and safety of cryoablation for treating inoperable PMTs causing TIO.
• To assess the impact of cryoablation on FGF23 levels, phosphate, and vitamin D metabolism.
• To determine the clinical outcomes in patients undergoing cryoablation for TIO.

Main Methods:

• Three patients with confirmed TIO and inoperable PMTs underwent tumor cryoablation.
• One patient received prior tumor embolization due to tumor size and vascularity.
• Treatment success was defined by normalization of serum phosphate and FGF23 levels.

Main Results:

• Cryoablation led to a rapid decrease in plasma FGF23 within 24 hours post-procedure.
• Serum phosphate normalized by post-procedure day 3, with increased renal tubular reabsorption.
• Significant improvements in 1,25(OH)2 vitamin D levels and clinical symptoms (pain, weakness) were observed.

Conclusions:

• Cryoablation is an effective and potentially safer alternative to surgery for TIO patients with inoperable tumors.
• The procedure rapidly normalizes key hormonal and metabolic markers associated with TIO.
• Cryoablation offers a viable treatment option for patients with challenging tumor characteristics or significant medical comorbidities.