Delineation of lung cancer with FDG PET/CT during radiation therapy

• Published in: Radiation oncology (London, England) England), 2018-11, Vol.13 (1), p.219-219, Article 219
• Main Authors: Ganem, J, Thureau, S, Gardin, I, Modzelewski, R, Hapdey, S, Vera, P
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Cancer; Cancer therapies; Carcinoma, Non-Small-Cell Lung - diagnostic imaging; Carcinoma, Non-Small-Cell Lung - radiotherapy; Care and treatment; Clinical Trials as Topic; Computed tomography; Delineation; Diagnosis; Feasibility studies; Female; Fluorine; Fluorodeoxyglucose F18; Humans; Image Interpretation, Computer-Assisted - methods; Image processing; Lesions; Life Sciences; Lung cancer; Lung cancer, Non-small cell; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - radiotherapy; Lymph nodes; Lymphatic system; Male; Medical imaging; Medical personnel; Methods; Middle Aged; Nodes; Non-small cell lung carcinoma; Patients; perPET-RT; PET imaging; PET/CT; Physicians; Positron emission; Positron emission tomography; Positron Emission Tomography Computed Tomography - methods; Radiation; Radiation therapy; Radiotherapy; Radiotherapy Planning, Computer-Assisted - methods; Segmentation; Tomography; Tumors
• ISSN: 1748-717X; 1748-717X
• DOI: 10.1186/s13014-018-1163-2

To propose an easily applicable segmentation method (perPET-RT) for delineation of tumour volume during radiotherapy on interim fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with non-small cell lung cancer (NSCLC). Sixty-seven patients (51 primary tumours, 60 lymph nodes), from 4 prospective studies, underwent an FDG PET/CT scan during the fifth week of radiation therapy, using different generations of PET/CT. Per-therapeutic PET/CT scans were delineated in consensus by two experienced physicians leading to the gold standard threshold to be applied. The mathematical expression of Th , the optimal threshold to be applied as a function of the maximum standard uptake value (SUV ), was determined. The performance of this method (perPET-RT) was assessed by computing the DICE similarity coefficient (DSC) and was compared with 8 fixed threshold values and 3 adaptive thresholding methods. Th verified the following expression: Th  = A.ln(1/SUV ) + B where A and B were 2 constants. A and B were independent from the generation of PET/CT, but depended on the type of lesions (primary lung tumours vs. lymph nodes). PerPET-RT showed good to very good agreement in comparison to the gold standard. The mean and standard deviation of DSC value was 0.81 ± 0.13 for lung lesions and 0.78 ± 0.15 for lymph nodes. PerPET-RT showed a significant better agreement than the other segmentation methods (p