Prediction of lung cancer spread and functional resectability by¹³³Xe radiospirometry

Abstract

Sixty-six patients with primary lung cancer who underwent thoracotomy were studied to determine the correlations among¹³³Xe radiospirometry, surgical procedures and histological extension of the lung cancer. Disturbance in the regional perfusion ($\dot Q$ per cent) was more prominent than disturbance of the regional ventilation ($\dot V$ per cent), as the pathological stage and t factor proceeded, while$\dot V$ per cent and$\dot Q$ per cent were disturbed almost equally in relation to the pathological n factor. Lobectomy was impossible in patients with a$\dot Q$ per cent of less than 33 per cent of the total, but low perfusion did not necessarily contraindicate surgery. The predicted post-operative FEV_1.0 was calculated according to the equation of (1-b/a × ($\dot V$ per cent or$\dot Q$ per cent)) × (preoperative FEV_1.0), where a and b were the number of subsegments in the lung lobes on the involved side and the resected lobe. The predicted and actually measured postoperative FEV_1.0 showed significant correlations (<0.001) in both equations. We conclude that$\dot Q$ per cent reflects a complex pattern of lung cancer spread more sensitively than does$\dot V$ per cent, and the significance of$\dot V$ per cent and$\dot Q$ per cent in terms of prediction of postoperative EFV_1.0 seems to be equivocal.