Objective: To investigate the difference between preoperative radiologic tumor volume (RTV) and postoperative pathologic tumor volume (PTV) in patients who received nephrectomy for renal cell carcinoma (RCC).
Materials and methods: We reviewed 482 patients who underwent preoperative computed tomography (CT) within 4 weeks before radical or partial nephrectomy for renal cell carcinoma. RTV measured by a three dimensional rendering program was compared with PTV (π/6 x height x length x width) measured in surgical specimen according to pathologic tumor size and histologic subtype. Correlation of the inter-quartile range (IQR) of the RTV and Fuhrman nuclear grade was also investigated.
Results: There was a significant positive linear correlation between RTV and PTV (p < 0.001, r = 0.911), and the mean RTV and mean PTV were not significantly different (79.0 vs 76.9 cm3, p = 0.393). For pathologic tumor size (PTS) < 4 cm, the mean RTV was larger than the mean PTV (10.9 vs 7.1 cm3, p < 0.001). For a PTS of 4-7 cm, the mean RTV was larger than the mean PTV (56.0 vs 44.7 cm3, p < 0.001). However, for a PTS ≥ 7 cm, there was no statistical difference between RTV and PTV (p > 0.05). Among patients with clear cell RCC, the mean RTV was significantly larger than the mean PTV (p = 0.042), not for non-clear cell group (p = 0.055). As the quartile of the RTV increased, the Fuhrman grade also increased (p < 0.001).
Conclusions: RTV was correlated with PTV and pathologic grade. RTV was larger than the PTV for a tumor size 7 cm or less or in clear cell RCC. RTV may be useful to measure tumor burden preoperatively.