Non-small cell lung cancer after surgery and chemoradiotherapy: follow-up and response assessment

The imaging techniques in patients treated for lung cancer may be challenging to interpret. Radiologists are often asked to evaluate computed tomography (CT) scans after surgery, and this interpretation requires an understanding of both the timing and type of the surgical procedure. However, follow-up strategies are still not well defined. The assessment of tumor response to chemoradiotherapy relies on a tight integration of CT and clinical findings. Positron emission tomography-computed tomography (PET-CT) with fluorodeoxyglucose may help to exclude tumor recurrence when the sole CT scan is equivocal. More efforts are needed to validate the tools for volumetric tumor measurement in routine practice and to demonstrate their superiority compared to the Response Evaluation Criteria in Solid Tumors (RECIST). Familiarity with the assessment of lung cancer perfusion is also important because of the increasing use of cytostatic therapy. In this review, we outlined the imaging assessment of tumor recurrence after surgery and the role of CT, magnetic resonance imaging, and PET-CT in the follow-up after chemotherapy, radiotherapy, and radiofrequency ablation.