IS COMPUTERIZED TOMOGRAPHY RELIABLE FOR DETECTING TUMOR NUMBER AND ADRENAL GLAND INVOLVEMENT IN PATIENTS WITH RENAL CELL CANCER? A MULTICENTER STUDY

Abstract

Abstract

Introduction: Renal cell cancer (RCC) represents the fifth most common cancer in men, with a rising

incidence. Computerized tomography (CT) remains the most appropriate imaging modality to diagnose renal

malignancies. Preoperative CT imaging provides to differentiate benign from malignant lesions, to assess

tumor size, tumor localization, tumor number, to identify lymph node and/or distant metastasis, adrenal gland

involvement, and to predict the presence of thrombus of the vena cava. Tumor number and the adrenal gland

involvement are the most important factors for surgical planning. In this regard, reliable radiographic

guidelines to assess the tumor number and the adrenal gland involvement preoperatively allow the surgeon to

select patients for partial nephrectomy or adrenal sparing procedures. In this study we examined preoperative

abdominal CT findings for tumor number and adrenal gland involvement. Subsequently these findings were

compared to histopathological results to determine the accuracy of CT in the diagnosis of tumor number and

adrenal involvement as well as establish parameters to ensure further accurate diagnosis.

Materials and Methods: We investigated 198 patients with RCC who were treated with radical

nephrectomy and ipsilateral adrenalectomy at five different medical centers from 2000 to 2004 retrospectively.

The mean age in the patients was 57.3 (15-86) years. Eighty-two of the patients were female, 116 were male.

Mean ages of the male and female patients were 58.1 and 57.7 years, respectively. Renal masses diagnosed with

contrast enhanced abdominal CT imaging. Also, tumor localization, tumor number, lymph node and adrenal

gland involvement were assessed preoperatively. All the patients underwent radical nephrectomy and

ipsilateral adrenalectomy. We assessed the accuracy of preoperative abdominal CT findings for identifying

tumor number and adrenal gland involvement compared with postoperative histopathological results.

Results: Mean tumor size was 8.0±3.6 (2-23) cm. At the end of the histopathological examination, Stage 1,

2, 3, and 4 tumors were detected in 72 (36.4%), 74 (37.4%), 49 (24.7%) and 3 (1.5%) patients, respectively.

Adrenal gland involvement was detected in 13 patients (6.5%) with histopathological examination. While

preoperative CT demonstrated adrenal gland involvement in 7 patients, histopathology reports confirmed only

in 4 patients. CT demonstrated a sensitivity of 30.8%, specificity of 98.4%, positive predictive value of 57.1%,

and negative predictive value of 95.2% for adrenal gland involvement. There was no significant difference

between upper pole tumors and other regions tumor with regard to adrenal gland involvement. While CT was

demonstrated unifocal tumor in 188 patients, histopathology reports were detected in 180 patients. CT

demonstrated a sensitivity of 20%, specificity 95.7%, positive predictive value of 20%, and negative predictive

value of 95.7% for detecting tumor multifocality.

Conclusion: In the light of our results, preoperative abnormal CT findings are less reliable for detecting

tumor multifocality and adrenal gland involvement. According to histopathological examination, preoperative

CT findings missed adrenal gland involvement and multifocal tumor in 4.7% and 4.3% of the patients.

Although, CT is more reliable diagnostic method for adrenal gland involvement and tumor multifocality,

either sophisticated radiological techniques or specific marker should be needed.