title: Evaluation of radiotherapeutic response in non-small cell lung cancer patients by technetium-99m MIBT and thallium-201 chloride SPET.
abstract: The purpose of this study was to investigate the relationship between technetium-99m hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) accumulation in tumours and response to radiotherapy in non-small cell lung cancer patients in comparison with the findings obtained using thallium-201 chloride (201Tl). Simultaneous dual single-photon emission tomography (SPET) imaging with 600 MBq 99mTc-MIBI and 111 MBq 201Tl was performed in 31 patients with biopsy- or sputum cytology-proven lung cancer. SPET images were acquired 15 min (early) and 2 h (delayed) after injection, and the early ratio, delayed ratio and retention index were measured. The tumours were classified into two groups on the basis of follow-up computed tomography (CT): responders (at least 50% reduction in tumour size) and non-responders (little or no change in tumour size). The mean (+/-SD) values of early ratio, delayed ratio and retention index using 99mTc-MIBI SPET were 3.0+/-1.1, 2.7+/-1.0 and -9.5+/-12.7, respectively, in responders and 2.4+/-0.7, 2.0+/-0.5 and -18.4+/-9.0, respectively, in non-responders. The corresponding values using 201Tl chloride SPET were 3.7+/-1.0, 4.7+/-1.5 and 24.2+/-22.1 in responders and 3.3+/-1.2, 4.0+/-1.3 and 20.4+/-20.5 in nonresponders. Using 99mTc-MIBI, the delayed ratio and retention index in responders were significantly higher than those in non-responders (P<0.01 and P<0.05, respectively). The results of this study indicate that patients with higher delayed ratio and retention index values using 99mTc-MIBI SPET are likely to respond better to radiotherapy than those with lower values. 99mTc-MIBI SPET may give an indication of the short-term response to radiotherapy in patients with non-small cell lung cancer.
authors.affiliation: Department of Radiology, Kagawa Medical University, Kagawa, Japan. nisiyosi@kms.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nishiyama
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Fukunaga
authors.forename: T
authors.initials: T
authors.lastname: Kiuchi
authors.forename: K
authors.initials: K
authors.lastname: Satoh
authors.forename: H
authors.initials: H
authors.lastname: Takashima
authors.forename: M
authors.initials: M
authors.lastname: Ohkawa
authors.forename: M
authors.initials: M
authors.lastname: Tanabe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D012542:Scattering, Radiation; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi