Monitoring the chemotherapeutic response in primary lung cancer using 99mTc-MIBI SPET.
Prediction and evaluation of the response to chemotherapy (CTx) are important for the correct and cost-effective treatment of patients with primary lung cancer. Although fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is accepted as the most useful and accurate nuclear medicine technique for this purpose, its expense and limited availability restrict its use. Compared with PET agents, technetium-99m methoxyisobutylisonitrile (MIBI), which is used in nuclear oncology, is cheaper and available in any nuclear medicine clinic. With this in mind, in this study we aimed to evaluate the role of 99mTc-MIBI in monitoring the chemotherapeutic response in primary lung cancer. Twenty patients with primary lung cancer underwent 99mTc-MIBI single-photon emission tomography (SPET) at 15 min (early) and 3-4 h (delayed) after injection of the tracer. All patients underwent 99mTc-MIBI SPET study twice: before and after the 3rd cycle of CTx. Patients were divided into two groups, responders [R(+), n=10] and nonresponders [R(-), n=10], according to the change in tumour size on CT scan taken 2 weeks after the last cycle of the CTx. From the SPET images early and delayed tumour/lung ratios (ER and DR) were obtained before and after CTx. In the R(+) group, ER and DR decreased significantly after CTx, from 3.28+/-1.55 to 1.78+/-0.72 (P<0.04) and from 3.23+/-1.55 to 2.0+/-0.88 (P<0.05), respectively. However, in the R(-) group, while ER showed a slight and statistically insignificant increase after CTx (from 2.51+/-1.23 to 2.65+/-1.86), DR increased significantly, from 2.74+/-1.37 to 3.27+/-2.31 (P<0.03). The percentage decreases in ER and DR in the R(+) group after CTx was significantly higher than that in the R(-) group: 34.36%+/-26.7% vs -13.78%+/-27.58% (P<0.0002) and 29.45%+/-25.23% vs -18.58%+/-20.51% (P<0.0005), respectively. Using a decrease of > or =10% as a threshold for monitoring the chemotherapeutic response, 99mTc-MIBI had a sensitivity of 90% and a specificity of 100%. We found a positive correlation in 14 patients between ER and DR and survival: r=0.6754 and P=0.008, and r=0.5755 and P=0.031, respectively. Our results suggest that 99mTc-MIBI might be used in routine practice to monitor the chemotherapeutic response in patients with primary lung cancer, especially when PET is not available.
Yüksel
M
M
Department of Nuclear Medicine, Trakya University Medical Faculty, Edirne, Turkey. mahmuty@trakya.edu.tr
Cermik
T F
TF
Karlikaya
C
C
Salan
A
A
Cakir
E
E
Gültekin
A
A
Berkarda
S
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000188:drug therapy; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging* / Q000188:drug therapy; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi