SPECT quantitation of cobalt-57-bleomycin to predict treatment response and outcome of patients with lung cancer.
Our hypothesis is that the concentration of 57Co-bleomycin (Co-bleo) in lung tumors reflects tumor cell kinetics and thus, prognosis. The relationship between the tumor concentration of Co-bleo measured in vivo by quantitative SPECT, response to chemotherapy and survival was investigated.


METHODS
Twenty patients with small-cell lung carcinoma (SCLC) and 49 patients with non-small-cell lung carcinoma (NSCLC) were studied. The concentration of Co-bleo was measured by SPECT in vivo in the tumor. The correlation between Co-bleo concentration in the tumor and the fraction of Co-bleo bound to DNA was investigated in an EMT6 murine tumor model and in samples of eight human tumors.


RESULTS
Tumors that did not respond to treatment showed a significantly higher Co-bleo concentration 8 hr after injection than tumors that responded (5.83% +/- 1.97% ID/cc * 10(-3) versus 2.55% +/- 1.23% ID/cc * 10(-3), p < 0.001). Values of Co-bleo concentration of 2.97% ID/cc * 10(-3) for SCLC and 2.72% ID/cc * 10(-3) for NSCLC were found to best separate patients into short- and long-term survival groups. In the EMT6 murine tumor model, a good correlation was found between the concentration of Co-bleo in the tumor and the fraction of Co-bleo bound to DNA (r = 0.75). In human tumor samples, a good correlation was found between DNA-bound Co-bleo measured in vitro and the concentration measured in vivo by SPECT (r = 0.85).


CONCLUSIONS
SPECT-measured Co-bleo concentration predicts the response to treatment and the outcome in patients with lung tumor by showing Co-bleo binding to DNA and tumor cell kinetics.
Even-Sapir
E
E
Department of Nuclear Medicine, Rambam Medical Center, Haifa, Israel.
Bettman
L
L
Iosilevsky
G
G
Milshtein
D
D
Frenkel
A
A
Kolodny
G M
GM
Ben-Haim
S
S
Israel
O
O
Front
D
D
D000368:Aged; D000369:Aged, 80 and over; D001761:Bleomycin / Q000031:analogs & derivatives; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000401:mortality; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality; D003037:Cobalt Radioisotopes; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate; D015899:Tomography, Emission-Computed, Single-Photon
D003037:Cobalt Radioisotopes; C030187:cobalt bleomycin; D001761:Bleomycin