A Comparative Study Between Planar Ga-67, TI-201 Images, Chest X-Ray, and X-Ray CT in Inoperable Non-Small Cell Carcinoma of the Lung
Authors: AHMAD M. RAGHEB, ABDEL-HAMEED H. ELGAZZAR, ALY K. IBRAHIM, EZZATT HIGAZI, ABDEL-RAHMAN MAHMOUD, KHALID EL-SALEH, YOUSEF T. OMAR, HUSSEIN M. ABDEL-DAYEM
Journal: Clinical Nuclear Medicine (1995)

Seventy patients with newly diagnosed, pathologically proven inoperable non-small cell lung cancer (NSCLC) had planar Ga-67, TI-201, chest x-ray, and chest CT imaging performed. Tumor/Normal tissue background (T/B) ratio was calculated for 62 Ga-67 and 55 TI-201 scintigraphy studies and comparisons were made between Ga-67 and TI-201 Imaging results regarding T/B ratios, site of lesion, and histologic type. The impact of the images on the initial knowledge of the extent of the tumor and on the radiotherapy (RT) planning was evaluated for each patient. For primary lesions, Ga-67 imaging results were positive in 94% (66 of 70 patients) versus 71% (50 of 70 patients) for TI-201 scans (P < 0.005) and the T/B ratio was > 1.5 in 74% (46 of 62 patients) for Ga-67 versus 36% (20 of 55 patients) for TI-201 (P < 0.0001). For centrally located lesions, sensitivity for Ga-67 was 100% (53 of 53 patients) versus 74% (39 of 53 patients) for TI-201 (P < 0.0005) and the T/B ratio > 1.5 in 84% (38 of 45 patients) for Ga-67 versus 38% (15 of 40 patients) for TI-201 (P > 0.001). For peripheral lesions, sensitivity of Ga-67 was 76% (13 of 17 patients) versus 64% (11 of 17) for TI-201 (P > 0.05) and the T/B ratio was < 1.5 in 47% (8 of 17 patients) for Ga-67 versus 33% (5 of 15 patients) for TI-201 (P < 0.05). The sensitivity of Ga-67 for squamous cell carcinoma was 92% (37 of 40 patients) versus 75% (30 of 40 patients) for TI-201 (P < 0.05). For adenocarcinoma Ga-67 sensitivity was 94% (15 of 16 patients) versus 69% (11 of 16 patients) for TI-201 (P < 0.05). For undifferentiated carcinoma, Ga-67 sensitivity was 100% (14 of 14 patients) versus 64% (9 of 14 patients) for TI-201 (P > 0.005). Mediastinal involvement as assessed by CT, Ga-67, and TI-201 was present in 89%, 51%, and 10%, respectively (P < 0.0001). For determination of the local extent of the tumor compared to the chest x-ray, Ga-67 scintigraphy added more information in 49% (34 of 70 patients) versus 27% (19 of 70 patients) for TI-201 (P < 0.005). When compared to CT, Ga-67 scintigraphy gave additional information in 4% (3 of 70 patients) of the patients versus 3% (2 of 70 patients) for TI-201 imaging. For the purpose of radiation therapy planning, if based on chest x-ray findings, Ga-67 scintigraphy was necessary for proper planning in 54% (38 of 70 patients) versus 27% (19 of 70 patients) for TI-201 imaging. If treatment planning was based on CT, Ga-67 scintigraphy added more information in 19% (13 of 70 patients) versus only 3% (2 of 70 patients) for TI-201 imaging. We conclude that Ga-67 scintigraphy is more useful than TI-201 imaging in the initial evaluation of NSCLC. Both are inferior to x-ray CT imaging for staging purposes and determining the local extent of the disease. Gallium-67 scintigraphy was necessary in some patients for proper radiation therapy treatment planning and adds more useful information to the x-ray CT imaging. Thaillum-201 imaging did not add more information to Ga-67 scintigraphy in any patient.