Diagnostic imaging of lung cancer after heart transplantation

In heart transplant recipients pulmonary neoplasms are among the most frequent solid tumors; they have a rapid and aggressive course, and therefore require an early diagnosis. We describe the role that diagnostic imaging plays in different diagnostic moments of this disease.

We evaluated the incidence and diagnosis of lung cancer in patients who underwent heart transplants at our institution. Taking into account the few different diagnostic imaging techniques (chest X-ray, high-resolution computed tomography [CT], staging CT and CT-guided biopsy) used in standard surveillance protocols or indicated by clinical symptoms, we evaluated their diagnostic accuracy, their efficacy in tumor staging, and their impact on the therapeutic choices.

Seventeen neoplasms in a total of 712 patients were diagnosed (2.4%). In 16 of these 17 cases chest X-ray (routinely performed as follow-up in 11 cases, indicated by symptoms in 5 cases) was diagnostic. In another 11 cases chest X-ray was false positive. The diagnostic accuracy, sensitivity, specificity, positive and negative predictive value of chest X-ray was 98%, 91%, 98%, 50%, and 99%, respectively. Total-body CT correctly staged the tumors and provided information as to whether surgery was indicated or not (stage II or advanced).

Chest X-ray is still the surveillance radiological technique in heart transplant recipients. Considering its low specificity and sensitivity, we propose high-resolution CT imaging during follow-up to identify pulmonary lesions as soon as possible and enable a differential diagnosis with parenchymal inflammation. The use of CT-guided fine-needle biopsy and culture examinations permits to differentiate neoplastic from inflammatory parenchymal opacities. Use of CT in cancer staging is effective for subsequent treatment choices.