Patient demographics and tumour characteristics are summarized in Table 1.
Primary technical success was achieved in 100% of procedures (n=46/46).
Primary efficacy was achieved in 94% (43/46 tumours).   There was no statistically significant difference in mean pre-procedure creatinine and creatinine one month post-procedure [ 112 mm/l (52-792 mm/l) v 110 mm/l (53-748 mm/l), p = 0.75].
Median length of stay was one day (range 0-13 days).   Complications occurred after 8% of ablation procedures (4/50).
One patient had an intra-procedure pneumothorax that required a chest drain insertion.
The second patient had an intra-procedure haemothorax requiring a chest drain.
The third patient developed a perinephric collection at 3 months post ablation that resulted in ipsilateral mild hydronephrosis treated with image-guided drainage and antibiotic treatment as an inpatient on a second unscheduled admission.
One patient developed acute urinary retention post procedure.
Table 2 compares patient demographics, tumour size and periprocedural outcomes between RFA and MWA.
Primary efficacy was greater in the RFA group compared to the MWA group (p=0.02).
Larger median RCC diameter was associated with failed primary efficacy in the MWA group (3.8 cm vs 2.4 cm respectively, p= 0.045).
Overall survival and local tumour control within 9 years of IGTA are described in Figure 2 and 3, respectively.