Surgical management of metastatic adrenal tumors: Decision-making factors in imaging

Abstract

The present study aimed to clarify decision-making factors based on imaging for laparoscopic adrenalectomy (LA) or open adrenalectomy (OA) for adrenal metastasis (AM) based on our previous experience. From November 2003 to November 2006, 11 adrenalectomies were performed for AM for malignancies such as lung cancer, renal cell carcinoma (RCC) and breast cancer at Tokai University Hospital. A diagnosis of AM for these malignancies was suspected whenever a newly diagnosed adrenal mass was located, characterized by a basal computed tomography (CT) density superior to 10 Hounsfield units, strong or heterogeneous vascular enhancement following contrast injection and/or increasing size in sequential imaging studies. There was no evidence of extra-AM. The approach to surgical management using LA or OA was determined on the basis of CT and/or magnetic resonance imaging. The patients were reviewed every 2 or 3 months by physical examination and systemic CT. We analyzed the decision-making factors based on imaging for surgical management with LA or OA from the results of oncological outcome, imaging, intraoperative and pathohistological findings. In this study, 9 patients underwent 11 adrenalectomies (9 laparoscopic and 2 open procedures). Non-small cell lung cancer was the most common primary malignancy (5 adrenalectomies of 4 patients), followed by RCC (4 adrenalectomies of 4 patients) and breast cancer (2 adrenalectomies of 1 patient). The median tumor size for the LA group was 3.1±0.7 cm (range 2.1-4.3) and for the OA group, 6.1±0.8 cm (5.5 and 6.7 cm) (p=0.001). The operative time for the LA group was 127±42 min (range 90-215) and for the OA group, 224±47 min (190 and 257 min) (p=0.018). Blood loss for the LA group was 49±63 g (range 3-207) and for the OA group, 340±10 g (333 and 347 g) (p<0.001). No complications were noted and no conversion of LA to OA occurred. All 9 adrenal tumors selected for LA were removed safely without strong adhesion to the surrounding tissue. Two adrenal tumors removed by OA had a strong adhesion to the surrounding tissue. All 9 patients had complete resection, without capsular disruption and a negative margin in the pathological findings. No port-site and local recurrences occurred. No patients presented with local relapse or port-site metastasis. Disease-free survival rate for the LA group was 57% and for the OA group, 50% (p=0.661). LA is a less invasive treatment than OA for AM. However, for complete resection, OA should be selected for cases where resection by LA is difficult. Therefore, in the decision making towards the appropriate surgical management with LA or OA, it is important to closely assess pre-operative imaging. Imaging features supporting OA include no detection of fatty tissue between the tumor and proximal organs, tumors with an irregular contour, large tumors and tumors with a cystic component.