LIMITATIONS OF PET SCAN IN THE DETECTION OF DISTAL METASTASES OF BRONCHOPULMONARY CANCER

Introduction: Positron Emission Tomography (PET) scanning has become essential in staging bronchopulmonary cancer, offering superior accuracy in detecting both mediastinal lymph node involvement and distant metastases. However, despite its advantages, PET scanning has notable limitations in detecting distal metastases. Objective: To highlight the limitations of PET scanning in detecting distal metastases of bronchopulmonary cancer, particularly those located outside the standard acquisition field, through the presentation of two clinical cases. Methods: We present two cases of bronchopulmonary cancer where PET scanning failed to detect distal bone metastases. The first case involves a tibial metastasis in a patient with squamous cell carcinoma, while the second case presents a humeral metastasis in a patient with small cell carcinoma. Results: In both cases, PET scanning, which typically covers only from the base of the skull to the upper third of the thighs, missed the distal bone metastases that were later detected through other imaging modalities and confirmed by biopsy or additional testing. These metastases were located outside the standard PET acquisition field. Conclusion: While PET scanning remains a cornerstone in bronchopulmonary cancer staging, practitioners must be aware of its limitations, thorough clinical examination and patient history remain essential components in the detection of distal metastases.