Technetium-99m Methoxyisobutylisonitrile Chest Imaging of Lung Cancer: Relation to Patient Prognosis and Chemotherapy Response

Objective: The purpose of this preliminary study was to evaluate retrospectively the relation between chemotherapy response and survival time using technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) uptake in lung cancer (small and nonsmall-cell carcinoma) and to detect the expression of multidrug resistance (mdr)-mediated P-glycoprotein (Pgp).

Design: Retrospective study on cases who have been diagnosed as lung cancer

Setting: The study group comprised 8 small-cell lung cancer (SCLC) and 6 nonsmall-cell lung cancer (NSCLC) (1 adenocar­cinoma, 5 epidermoid carcinomas) cases. All cases were male, ages 49 to 68 years.

Interventions: Fourteen patients with lung cancer, prior to admin­istration of chemotherapy (for SCLC cisplatin 60 mg/m2, etoposide 120 mg/m2 [3 days], for NSCLC cisplatin 50 mg/m2, mitomycin 6 mg/m2, Ifosfamide 3000 mg/m2 or cisplatin 20 mg/m2, vinorelbine 30 mg/m2 [1st and 8£^ days]), were enrolled in this study to undergoTc-99m MIBI chest imaging, including single photon emis­sion computed tomography (SPECT) and planar imaging and com­puted tomograhy (CT), applied just before and subsequent to the 3rtl chemotherapy. Response to chemotherapy was assessed accord­ing to WHO’s criteria; completed response (CR) and partial response (PR) were defined as good responses, nonresponse (NR) and progressive diseesa (PDR) were defined as poor responses. Tumor uptake ratio (TUR) was calculated from a formula taking into account total counts in the regions of interest (ROI) over the tumor and total counts in the contralateral normal lung tissue.

Measurements and results: Thirteen of the 14 (92%) cases (6 NSCLC and 7 SCLC) could be detected by visual interpretation of Tc-99m MIBI chest SPECT images. Four patients for each can­cer group completed chemotherapy. One of 4 with SCLC (25%) and 3 of 4 with NSCLC (75%) were good responders to chemotherapy. There was a significant positive correlation between tumor uptake ratio (TUR) and survival time (r= 0.73, p=0.036). The value of Tc-99m MIBI in predicting response to chemotherapy could not be demonstrated statistically. This result was possibly due to the small number of patients in the series.

Conclusion: Tc-99m MIBI chest images have the potential to predict patient survival time and prognosis in patients with lung cancer.