Purpose
Cooperative studies support complete metastasectomy in osteosarcoma (OS). Pre-operative CT is used to identify and quantify metastases and can facilitate minimally invasive techniques. Here we assess the accuracy of pre-operative CT compared to findings at thoracotomy and its change over time.
Methods
We reviewed OS thoracotomies performed at our institution from 1996-2015. The number of metastases identified on pre-operative chest CT was compared to the number of metastases seen on pathology (both metastases with viable cells and non-viable, osteoid-only metastases).
Results
Eighty-eight patients underwent 161 thoracotomies with a median of 14 days (range, 1-85) between CT and surgery, a median of 2 CT-identified lesions (range, 0-15), and a median of 4 resected lesions (range, 1-25). In 56 (34.8%) cases, more metastases were found surgically than were seen on CT, and among these, 34 (21.1%) had a greater number of viable metastases. There was poor overall correlation between CT and pathology findings (Kendall Tau-b = 0.506), regardless of CT slice thickness, decade of thoracotomy, or total number of CT-identified lesions.
Conclusions
CT accuracy in pre-operatively quantifying OS pulmonary metastases has not improved in recent decades. Consequently, we recommend an open technique with direct lung palpation for complete identification and resection of OS pulmonary metastases.