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PARTIAL VOLUME EFFECT CORRECTION IN PET/CT WITH 11C-METHIONINE FOR THE PATIENTS WITH LUNG LESIONS

 

Tlostanova M.S., Chipiga L.A.

Purpose. To evaluate the impact of partial volume effect (PVE) on the diagnostic information obtained from PET/CT examinations with 11C-methionine for the differential diagnostics of lung lesions.

Material and methods. PET/CT with 11C-methionine was performed for 52 patients with malignant tumors, 9 patients with benignant lesions and 50 patients with inflammations. Patients and phantom NEMA IEC PET Body were scanned on the PET/CT Discovery 690 with the same clinical protocol for lung. The patient scan was performed in 15-20 minutes after injection of 300 MBq/m2 of 11C-methionine. Recovery coefficients (RC), maximum standardized uptake values (SUVmax) in the images and SUVmax corrected by RC (SUVcorrect) as well as their relative differences were estimated for each patient. The impact of lesion size on the SUV, sensitivity, specificity, diagnostic accuracy, positive and negative prognostic values.

Results. Lesion size of patients with malignant tumors was significantly lower (15.4 ± 0.95 mm, 12 mm median) (p<0,0001) compared to the size benignant lesions and inflammations (21.7 ± 0.95 mm, 20 mm median) respectively. The maximum underestimation of SUVmax by 65% on average (22-65%) was determined for lesions of 8-12 mm size. The overestimation of SUVmax by 1-6% (p≥0.05) was determined for the lesions of 22-37 mm size. Sensitivity, specificity, diagnostic accuracy, positive and negative prognostic values of method for SUVmax>2.3 vs SUVcorrect>3.1 were 82.7% vs 84.6%, 66.1% vs 94.9%, 73.4% vs 90.0%, 68.2% vs 93.6%, 81.3% vs 87.5% respectively. Sensitivity of PET/CT with 11C-methionine was 70.4% and specificity was 100% (area under the curve 0.80) for patients with lesions of 8-12 mm and SUVmax>2.1. Sensitivity increased to 96.3%, and specificity remained 100% (area under the curve 0.99) for SUVcorrect>2.7.

Conclusion. PVE correction method significantly increased the diagnostic information of PET/CT with 11C-methionine for the differential diagnostics of lung lesions.

 

Granov Russian Research Center of Radiology and Surgical Technologies. Saint Petersburg, Russia.

Keywords: PET/CT, 11С-methionine, lung lesion, standardized uptake values, recovery coefficients, partial volume effect, NEMA IEC PET Body phantom.

 

Corresponding author:  Tlostanova M.S., e-mail: Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript

 

For citation: Tlostanova M.S., Chipiga L.A. Partial volume effect correction in PET/CT with 11C-methionine for the patients with lung lesions. REJR 2021; 11(3):107-119. DOI: 10.21569/2222-7415-2021-11-3-107-119.

Received:        30.04.21 Accepted:       30.08.21