The utility of gallium-68 DOTATOC PET/CT in lymphangioleiomyomatosis

Abstract

Somatostatin receptor functional imaging is of limited utility as an imaging biomarker in LAM, but other PET/CT modalities may be of use https://bit.ly/3l6BVZp.

FIGURE 1

Qualitative and quantitative assessment of ⁶⁸Ga-DOTA-TyI³-octreotide (DOTATOC) positron emission tomography (PET)/computed tomography (CT) in lymphangioleiomyomatosis (LAM). a) Axial thoracic CT image at the level of the carina in a patient with mild LAM (forced expiratory volume in 1 s (FEV₁): 99% of predicted; diffusing capacity of the lung for carbon monoxide (D_LCO): 88% of predicted) demonstrates occasional scattered thin-walled cysts. c) No increased tracer uptake evident on the axial fused ⁶⁸Ga-DOTATOC PET/CT image (maximum standardised uptake value (SUV_max) window range 0–5). b) A separate patient with severe LAM (FEV₁: 36% of predicted; D_LCO: 25% of predicted) has innumerable cysts demonstrated on this axial thoracic CT image at the level of the aortic arch. d) No increased pulmonary tracer uptake evident on ⁶⁸Ga-DOTATOC PET/CT. Dashed line: sample region of interest demonstrated on PET images panels c and d. e) Semiquantitative SUV_max measures of pulmonary ⁶⁸Ga-DOTATOC uptake in lungs of patients with LAM and controls. f) Target to background ratio for each lobe calculated by dividing the lobar SUV_max by the mediastinal blood pool SUV_max in lungs of patients with LAM and controls. Each dot represents an individual patient. Data are presented as mean±sd. LAM, n=4; control; n=4. ns: nonsignificant. *: p<0.05, unpaired Student's t-test.