Reply to: Radiological Experience Needed When Assessing PET/CT Imaging

I would like to thank the Author/s for their interest in my article [1]. A study that triggers a stimulating discussion with colleagues can contribute to standardizing diagnostic approaches and improving healthcare. Lung nodule management, when a preoperative histologic diagnosis is impossible, will always generate some perplexity with regard to the choice of whether to pursue an aggressive or a conservative management approach. Based on this, I wish to put forward the following considerations:

No patient in our study showed a radiological image which would have allowed us to establish the benign or malignant nature of the lesion through changes in nodular characteristics. A single pulmonary nodule was discovered accidentally with computerized tomography (CT), and its topography contraindicated the CT-guided needle biopsy (CTNB) or video-assisted thoracoscopy (VAT). In this clinical situation, follow-up CT of the thorax should be avoided as it may delay the diagnosis of lung cancer. Thin-section CT imaging, contrary to high resolution CT and conventional CT used in our study, highlights the localization and the morphological aspects of a small lesion, offering a presumptive diagnosis. However, only a mass biopsy with a histopathologic evaluation will confirm the suspicion aroused by the CT images. This correlation was better explained by Park et al. 2 for ground-glass opacities (GGO) which constituted 7.2 % of lesions in our experience. VAT or CTNB are the main diagnostic modalities for peripheral solitary small lung mass. Shimizu et al. 3 reported a CTNB diagnostic yield in a GGO-preponderant group of 35.2 % for nodules smaller than 1 cm and of 50 % for nodules with diameters of 1.1–1.5 cm. In the solid-preponderant group, the diagnostic yield was 62.5 % for nodules smaller than 1 cm and 75 % for 1.1–1.5 cm nodules. If VAT or CTNB is impossible owing to the central lung location of the lesion, the surgeon can choose between open biopsy or CT follow-up. I am of the opinion that the latter choice inhibits the preclinical diagnosis of primary or secondary lung cancer, which is necessary for radical surgical treatment and a good prognosis. 18-Fluorine fluorodeoxyglucose positron emission tomography with computerized tomography (18F‐FDG PET/CT) can contribute to characterizing the malignant solitary nodule and should thus reduce the doubts of patients concerning the necessity of a minithoracotomy. I agree that an exchange of communications and of information between different medical professionals is the ideal method to obtain good results in bronchogenic carcinoma. The thoracic surgeon is the main person responsible for the patient, because he/she must take the final decision for surgery and determine the surgical approach. In my opinion, the thoracic surgeon must be familiar with and be able to read radiological images (CT, PET/CT) along with carrying out the bronchoscopy, as this can reduce intraoperative and postoperative complications.

I hope that the different practices highlighted in this discussion may prompt a comparative study between ¹⁸F‐FDG PET/CT and thin-section CT imaging in solitary lung nodule management.

References

• 1 Divisi D, Di Tommaso S, Di Leonardo G, Brianzoni E, De Vico A, Crisci R. 18-fluorine fluorodeoxyglucose positron emission tomography with computerized tomography versus computerized tomography alone for the management of solitary lung nodules with diameters inferior to 1.5 cm.  Thorac Cardiovasc Surg. 2010;  58 422-426
• 2 Park C M, Goo J M, Lee H J, Lee C H, Chun E J, Im I G. Nodular ground-glass opacity at thin-section CT: histologic correlation and evaluation of change at follow-up.  Radiographics. 2007;  27 (2) 391-408
• 3 Shimizu K, Ikeda N, Tsuboi M, Hirano T, Kato H. Percutaneous CT-guided fine needle aspiration for lung cancer smaller than 2 cm and revealed by ground-glass opacity at CT.  Lung Cancer. 2006;  51 (2) 173-179