Imaging strategy and outcome following partial nephrectomy.

OBJECTIVES: The aim of this study was to analyze the outcomes of surveillance after partial nephrectomy (PN) in a single institution and the relevance of imaging studies in detecting recurrence.

MATERIAL AND METHODS: Retrospective study of 830 patients who underwent PN for localized renal cell carcinoma between 2007 and 2015 at a single institution. We studied the characteristics of recurrence according to pathological and clinical features and elaborated risk groups. The type and the total number of imaging studies performed during surveillance or until recurrence were evaluated. Outcomes of surveillance were analyzed.

RESULTS: There were 48 patients (5.8%) diagnosed with recurrence during median 36 [21-52] months follow-up, including local recurrence in 18 patients (37.5%) and metastasis in 30 patients (62.5%). Totally, 17/18 patients (94.4%) with local recurrence and 26/30 patients (86.6%) with metastasis were diagnosed within the first 36 months after PN. When studying the recurrence rate, and time-to-recurrence, 2 risk groups emerged. Patients with pathological characteristics (tumors with pT1b or higher or high-grade tumor or positive surgical margin status) or patients with anatomical characteristics (high or moderate R.E.N.A.L. score) or both had high recurrence rate. Chest x-ray and abdominal ultrasound detected 7.7% and 3.4% of all recurrences, respectively, whereas computed tomography scan and magnetic resonance imaging scan detected the rest. Of the 48 patients diagnosed with recurrence, 44 (91.6%) were suitable for secondary active treatment (systemic, surgery, and radiotherapy) including 26 (54.2%) suitable for metastasectomy. The rate of relapse after secondary treatment was 43.5% (16.6% for the local recurrence group and 60.7% for metastasis group).

CONCLUSION: Local recurrence emerges earlier than distant metastasis. Patients with any adverse pathological or anatomical features should be considered as high-risk group and followed closely in the first 36 months after PN with cross-sectional studies. Secondary active treatment is suitable for most patients, while surgical treatment fits fewer patients. Local recurrence is associated with increased rates of metastatic progression.