PET/CT imaging in response evaluation of SCLC patients

Utility of Molecular Imaging with 2-Deoxy-2-[Fluorine-18] Fluoro-DGlucose Positron Emission Tomography (18F-FDG PET) for Small Cell Lung Cancer (SCLC): A Radiation Oncology Perspective

BACKGROUND AND OBJECTIVE

Although accounting for a relatively small proportion of all lung cancers, small cell lung cancer (SCLC) remains to be a global health concern with grim prognosis. Radiotherapy (RT) plays a central role in SCLC management either as a curative or palliative therapeutic strategy. There has been considerable progress in RT of SCLC, thanks to improved imaging techniques leading to accurate target localization for precise delivery of RT. Positron emission tomography (PET) is increasingly used in oncology practice as a non-invasive molecular imaging modality.

METHODS

Herein, we review the utility of molecular imaging with 2-deoxy-2-[fluorine-18] fluoro-Dglucose PET (18F-FDG PET) for SCLC from a radiation oncology perspective.

RESULTS

There has been extensive research on the utility of PET for SCLC in terms of improved staging, restaging, treatment designation, patient selection for curative/palliative intent, target localization, response assessment, detection of residual/recurrent disease, and prediction of treatment outcomes.

CONCLUSION

PET provides useful functional information as a non-invasive molecular imaging modality and may be exploited to improve the management of patients with SCLC. Incorporation of PET/CT in staging of patients with SCLC may aid in optimal treatment allocation for an improved therapeutic ratio. From a radiation oncology perspective, combination of functional and anatomical data provided by integrated PET/CT improves discrimination between atelectasis and tumor, and assists in the designation of RT portals with its high accuracy to detect intrathoracic tumor and nodal disease. Utility of molecular imaging for SCLC should be further investigated in prospective randomized trials to acquire a higher level of evidence for future potential applications of PET.

Diagnostic efficacy of PET and PET/CT for recurrent lung cancer: a meta-analysis

BACKGROUND

Lung cancer is one of the most common malignant tumors in the world, and is the leading cause of cancer-related mortality. Although there are no conclusive data to support the survival benefits of early detection or early treatment for recurrence, an early and accurate diagnosis of recurrence is critical to optimize therapy.

PURPOSE

To compare the diagnostic value of positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) using fluorine-18 deoxyglucose (18FDG) with conventional imaging techniques (CITs) for the detection of lung cancer recurrence.

MATERIAL AND METHODS

A meta-analysis was performed, with systematic searches conducted using PubMed and EMBASE databases (up to 31 December 2011). Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) values were calculated for 1035 patients reported in 13 articles. Summary receiver-operating characteristic curves (SROC) were also generated.

RESULTS

The pooled sensitivity (95% CI) for PET, PET/CT, and CITs were 0.94 (0.91-0.97), 0.90 (0.84-0.95), and 0.78 (0.71-0.84), respectively. The pooled specificity (95% CI) for PET, PET/CT, and CITs were 0.84 (0.77-0.89), 0.90 (0.87-0.93), and 0.80 (0.75-0.84), respectively. Regarding sensitivity, lower values were associated with CITs than PET (P = 0.000) and PET/CT (P = 0.005), and there was no significant difference between PET/CT and PET (P = 0.102). Regarding specificity, values for PET/CT and PET were significantly higher than for CITs (both P = 0.000), and there was no significant difference between PET/CT and PET (P = 0.273). In the SROC curves, a better diagnostic accuracy was associated with PET/CT than PET and CITs.

CONCLUSION

PET/CT and PET were found to be superior modalities for the detection of recurrent lung cancer, and PET/CT was superior to PET.