Delineation of lung cancer with FDG PET/CT during radiation therapy.
Radiat Oncol
; 13(1): 219, 2018 Nov 12.
Article
in En
| MEDLINE
| ID: mdl-30419929
OBJECTIVES: 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). MATERIAL AND METHODS: 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 Thopt, the optimal threshold to be applied as a function of the maximum standard uptake value (SUVmax), 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. RESULTS: Thopt verified the following expression: Thopt = A.ln(1/SUVmax) + 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 < 0.001), except for one of the adaptive thresholding method ADT (p = 0.11). CONCLUSION: On the database used, perPET-RT has proven its reliability and accuracy for tumour delineation on per-therapeutic FDG PET/CT using only SUVmax measurement. This method may be used to delineate tumour volume for dose-escalation planning. TRIAL REGISTRATION: NCT01261598 , NCT01261585 , NCT01576796 .
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Radiotherapy Planning, Computer-Assisted
/
Carcinoma, Non-Small-Cell Lung
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Positron Emission Tomography Computed Tomography
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Lung Neoplasms
Type of study:
Observational_studies
Limits:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Radiat Oncol
Journal subject:
NEOPLASIAS
/
RADIOTERAPIA
Year:
2018
Document type:
Article
Affiliation country:
France
Country of publication:
United kingdom