The value of gamma camera and computed tomography data set coregistration to assess Lewis Y antigen targeting in small cell lung cancer by (111)Indium-labeled humanized monoclonal antibody 3S193.
OBJECTIVE
To assess the value of data set coregistration of gamma camera and computed tomography (CT) in the assessment of targeting of humanized monoclonal antibody 3S193 labeled with indium-111 ((111)In-hu3S193) to small cell lung cancer (SCLC).


METHODS
Ten patients (6 male and 4 female; mean age+/-S.D., 60+/-4 years), from an overall population of 20 patients with SCLCs expressing Lewis Y antigen at immunohistochemical analysis, completed a four weekly injections of (111)In-hu3S193 and underwent gamma camera imaging. All had had, as part of their baseline evaluation, Fluorine18 fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Two readers in consensus retrospectively coregistered the gamma camera images with the CT component of the FDG PET/CT by automatic or manual alignment. The resulting image sets were visually examined and SCLC lesions targeting at coregistered gamma camera and CT was correlated side-by-side with the (18)F-FDG uptake.


RESULTS
A total number of 31 lesions from SCLC with a thoracic (n=13) or extrathoracic location (n=18) were all positive on FDG PET/CT. Coregistration of the gamma camera to the CT demonstrated targeting of antibody to all lesions >2 cm (n=20) and in a few lesions < or =2 cm (n=2), with no visualization of most lesions < or = 2 cm (n=9). No (111)In-hu3S193 uptake in normal tissues was observed.


CONCLUSIONS
Coregistration of antibody gamma camera imaging to FDG PET/CT is feasible and allows valuable assessment of (111)In-hu3S193 antibody targeting to SCLC lesions >2cm, while lesions < or =2 cm reveal a limited targeting.
Quaia
Emilio
E
Department of Radiology, Cattinara Hospital, University of Trieste, Strada di Fiume 447, 34149 Trieste, Italy. Electronic address: quaia@units.it.
Krug
Lee M
LM
Thoracic Oncology Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Pandit-Taskar
Neeta
N
Nuclear Medicine Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Nagel
Andrew
A
Nuclear Medicine Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Reuter
Victor E
VE
Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Humm
John
J
Nuclear Medicine Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
Divgi
Chaitanya
C
Division of Nuclear Medicine and Clinical Molecular Imaging, Hospital of the University of Pennsylvania, 3400 Spruce Street, Room Donner 116, Philadelphia, PA 19104, USA.
D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D005260:Female; D015902:Gamma Cameras; D049671:History, 18th Century; D006801:Humans; D007205:Indium Radioisotopes / Q000493:pharmacokinetics; D007983:Lewis Blood Group Antigens / Q000378:metabolism*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000276:immunology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D016499:Radioimmunotherapy / Q000379:methods*; D011877:Radionuclide Imaging; D055752:Small Cell Lung Carcinoma / Q000000981:diagnostic imaging* / Q000276:immunology / Q000628:therapy; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D051598:Whole Body Imaging
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C522039:Hu3S193 monoclonal antibody; D007205:Indium Radioisotopes; D007983:Lewis Blood Group Antigens; C094162:Lewis Y antigen