Introduction

Partial nephrectomy (PN) has been increasingly used for the treatment of small renal mass. However, percutaneous radiofrequency ablation (RFA) has been accepted as a minimally invasive treatment option. In this study, we evaluated the oncologic results, functional outcomes and complications after PN or percutaneous RFA for the treatment of small sized (4cm or less) Bosniak III or IV cystic renal lesions.

Methods

We retrospectively reviewed medical records of 135 patients who underwent PN (99) or RFA (36) for small sized (4cm or less) Bosniak III or IV cystic renal lesions between January 2009 and December 2014. After excluding patients with hereditary cystic disease or less than 12 months of follow-up, 128 (PN, 97; RFA, 31) patients remained for analysis. Pathologic characteristics, tumor violation during surgery, residual tumor, local recurrence and distant metastasis data were collected. Glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations and checked preoperatively, 1 month, 6 months, and 12 months postoperatively. All complications were graded by Clavien classification system.

Results

The median size of Bosniak III or IV cystic renal lesions was 2.6cm. Renal cell carcinoma (RCC) accounted for 86.6% (84/97) of patients in PN group. In RFA group, histologic subtype was identified in 32.3% (10/31) of patients, but 90.0% (9/10) of patients revealed RCC. One case of tumor violation occurred in PN group and 2 cases of residual cancer were observed in RFA group. But there were no local recurrence or distance metastasis in both groups during the median follow-up of 34.0 months. Compared with PN group, patients in the RFA group showed a small decrease of percent change of CKD-EPI GFR at 1 month (-13.6% vs -6.8%, p=0.039). Perioperative complication rate in PN group was 29.9% and 22.6% in RFA group. According to Clavien classification system, Grade IIIa complications rate was 4.1% in PN group and 6.5% in RFA group. There were no grade IIIb and IV complications

Conclusions

The results of our study indicated that percutaneous RFA showed comparable oncologic results and complications and better early preservation of renal functions than PN.

Funding

None