Chondroblastoma treatment by radiofrequency thermal ablation: Initial experience and implementation.

PURPOSE

To present our experience on the implementation of radiofrequency thermal ablation (RFA) for the treatment of chondroblastoma.

MATERIALS AND METHODS

This case series includes 12 patients (10 males) with chondroblastoma using RFA under CT guidance. Tumours were located in the humeral head (3), femoral head (2), distal femoral epiphysis (4), tibial epiphysis (2) and calcaneus (1). Tumour size ranged from 12 to 60 mm (median: 33 mm). According to tumour size and location, monopolar electrode's active tip ranged from 1 to 3 cm. Dry and perfused ablation mode was used to treat smaller (6) and larger (6) lesions, respectively. Cementation was also made in 5 cases. Technical success was considered if the tumour was treated according to the protocol and complete ablation was achieved. Clinical success was assessed according to a visual analogue scale.

RESULTS

Technical success was achieved in 11 of 13 cases (83%) afters the first treatment. After a second treatment in the 2 failed cases, pain control was achieved in all cases eventually (100% of clinical success). Follow-up MRI demonstrated resolution of oedema in all cases, as well as a necrotic area extending beyond the outer edge of the lesion in all cases except one. Radiography or CT showed stability of the lesions, with increased sclerosis and no cortex collapse. In one case, a 4 cm shortening of the humerus was observed at the end of skeletal development (7 years after treatment). In another case, early hip osteoarthritis was developed (15 years after treatment). No other long-term complications were observed.

CONCLUSION

Successful treatment of chondroblastoma can be achieved by RFA. Cementoplasty adds strength to the ablated bone in weight bearing areas. MRI hallmarks associated with clinical success were resolution of bone marrow edema, and area of necrosis extending beyond the tumour edge. Radiography and CT proved to be useful in demonstrating cortex integrity.