Fast cancer uptake of 99mTc-labelled bombesin (99mTc BN1).
In human blood, breakdown of gastrin-releasing peptide and other bombesin-related peptides occurs in less than 15 min. This quick enzymatic cleavage might impair the diagnostic use of labelled bombesin (BN). 99mTc-labelled bombesin (99mTc BN1) was injected intravenously and dynamic uptake data were acquired for diagnosing 26 cancers of different origin: 15 breast, 3 prostate, 5 colo-rectal, 1 pancreas, 2 small cell lung cancers and 1 gastrinoma. Background subtracted tumour uptake data were plotted against time and fitted with known mathematical functions. Twenty-three out of 26 cancers showed rapid increase of radioactivity followed by a radioactivity plateau, with some oscillations around the average plateau value. The time to 80% of max activity (T80) was the reference parameter to measure and to compare the uptake speeds. The slowest T80 was 7 min in one T1b breast cancer, gastrinoma reached T80 in 5 min and node-positive prostate cancers in 2 min. N+ breast cancers showed T80 at 3.62 +/- 0.75 min, N- breast cancers at 5.5 +/- 0.88 min (p < 0.02). When all the tumours were considered, N+ tumours showed T80 at 2.68 +/- 1.03 min and N- cancers at 5.5 +/- 0.82 min. In all the cancer types, the uptake of 99mTc BN was faster than 10 min. This result shows the ability of 99mTc BN to image tumours. The faster uptake by N+ versus N- cancers probably depends on the higher blood flow in N+ cancers.
Scopinaro
F
F
Department of Scienze Radiologiche, University "La Sapienza", Rome, Italy. francesco.scopinaro@uniroma1.it
Di Santo
G P
GP
Tofani
A
A
Massari
R
R
Trotta
C
C
Ragone
M
M
Archimandritis
S
S
Varvarigou
A D
AD
D001839:Bombesin / Q000031:analogs & derivatives*; D001943:Breast Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D018288:Carcinoma, Small Cell / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D003110:Colonic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D015408:Gastrinoma / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008175:Lung Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D008297:Male; D009367:Neoplasm Staging; D009369:Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000378:metabolism*; D015609:Organotechnetium Compounds; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D018004:Receptors, Bombesin / Q000378:metabolism; D012004:Rectal Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D012039:Regional Blood Flow
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D018004:Receptors, Bombesin; D001839:Bombesin