Scintigraphic prediction of resistance to radiation and chemotherapy in patients with lung carcinoma: technetium 99m-tetrofosmin and thallium-201 dual single photon emission computed tomography study.
BACKGROUND
Various prognostic markers for lung carcinoma have been proposed, but to the authors' knowledge none is noninvasive and convenient for clinical use. The current study examined the utility of several radiotracers for the prediction of multidrug resistance (MDR) and radioresistance in patients with lung carcinoma.


METHODS
Thirty patients with untreated lung carcinoma underwent a dual isotope single photon emission computed tomography (SPECT) scan at 10 minutes and 120 minutes after the injection of technetium-99m ((99m)Tc)-tetrofosmin ((99m)Tc-TF) (370 megabecquerels [MBq]) and thallium-201 ((201)TlCl) (111 MBq). Retention of each tracer was evaluated semiquantitatively. Using radiation and chemotherapy (cisplatin plus etoposide), the patients either were treated sequentially (n = 12) or concurrently (n = 18). The relation between therapeutic response and retention of each tracer was analyzed. The detectability of radioresistance was examined.


RESULTS
In patients treated with sequential therapy, the response to radiation was predicted by (99m)Tc-TF retention, whereas (201)Tl retention was found not to be predictive. Regardless of whether the sequential or concurrent protocol was applied, 14 of 18 tumors with high (99m)Tc-TF retention (>/= 15%) exhibited a favorable response to chemoradiotherapy whereas all 12 tumors with low (99m)Tc-TF retention (</= 15%) did not respond to the therapy. In contrast, (201)Tl retention was not found to be a predictive factor.


CONCLUSIONS
The employed SPECT method is a useful tool for the in vivo prediction of radioresistance, P-glycoprotein (P-gp), and non-P-gp MDR in lung carcinoma. Low (99m)Tc-TF retention serves as a strong predictor of therapeutic resistance. High (99m)Tc-TF retention implies a favorable response. (201)Tl did not appear to be a predictive factor but is required for localization of the lesion on SPECT imaging.
Fukumoto
M
M
Department of Radiology, Kochi Medical School, Kochi, Japan.
Yoshida
D
D
Hayase
N
N
Kurohara
A
A
Akagi
N
N
Yoshida
S
S
D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging* / Q000628:therapy; D002945:Cisplatin / Q000627:therapeutic use; D003131:Combined Modality Therapy; D018432:Drug Resistance, Multiple; D004358:Drug Therapy; D005260:Female; D006801:Humans; D007700:Kinetics; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D008297:Male; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011379:Prognosis; D011836:Radiation Tolerance; D011878:Radiotherapy; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D013794:Thallium Radioisotopes; C078700:technetium tc-99m tetrofosmin; D002945:Cisplatin