LONG-TERM OUTCOME OF RADIO FREQUENCY ABLATION FOR SMALL RENAL MASS504

20. Chawla SN, Crispen PL, Hanlon AL, Greenberg RE, Chen DYand Uzzo RG: The natural history of observed enhancingrenal masses: meta-analysis and review of the world liter-ature. J Urol 2006; 175: 425.

EDITORIAL COMMENT

RFA for renal masses with curative intent has become in-creasingly applied to manage small renal tumors, particu-larly in patients with significant comorbid conditions. Asgroups at more centers report their data, it appears that thismodality is durable in the properly selected patient, at leastup to 4 to 5 years after the procedure. Success is directlyrelated to tumor size and location. Tumors most successfullytreated are those that are exophytic, externally bordered byfat, not located in the hilum or near the ureter and less than4 cm.

In this study 16 patients with an initial biopsy of RCCwere treated, of whom 3 showed recurrence at a minimumfollowup of 3½ years. Although a number of benign lesionswere also treated and it is useful to report complications,only the patients with biopsy proven RCC are the appropri-ate cohort in which to determine oncological efficacy. Thus,of these patients with a minimum followup of 3½ years 80%were recurrence-free. It is important to report results withthe minimum followup rather than the average followup ofthe group when establishing a new treatment modality. It isalso important to note, particularly in patients with signif-icant comorbid conditions, how many actually survived theminimum followup, so that an oncological outcome can bereported.

This study along with others suggests that, as evidencecontinues to accumulate, this technique shows great prom-ise. However, for it to be accepted as a standard of care anumber of patients with a minimum followup of at least 5

years and preferably 10 years is required before the method

can take its place alongside partial nephrectomy as thestandard of care.

W. Scott McDougalDepartment of Urology

Massachusetts General HospitalBoston, Massachusetts

REPLY BY AUTHORS

We agree that longer and larger studies are needed beforeminimally invasive therapies such as RFA are consideredoncologically equivalent to extirpative therapies such as par-tial nephrectomy. To clarify our results, only 2, not 3, of the16 patients with renal cell carcinoma on initial biopsy hadrecurrence. One patient with a negative initial biopsy alsohad recurrence which later proved to be RCC on pathologicalreview after salvage laparoscopic nephrectomy. In addition,another patient with an initial negative biopsy was con-firmed to have RCC at repeat RFA. This patient did nottolerate the original session secondary to pain and under-went laparoscopic guided biopsy on completion of RFA. Thisbrought our total to 18 of 31 patients with pathologicallyconfirmed RCC, 3 of whom had recurrence.

We presented our data in this manner to not only describethe overall outcomes of a cohort of patients with solitaryrenal masses who received RFA, but also to be as transpar-ent as possible. We stress the importance of close followup ofeven those patients with a negative biopsy, since in ourcohort RCC was pathologically confirmed in 2 of 15 patientsand 1 had recurrence. Better techniques for subtyping renaltumors (eg serologic, genetic and/or radiographic) are re-quired to aid in selecting patients who need treatment anddetermining which of those may be most suitable for abla-

tive therapy.