Clinical value of gallium-67 SPECT scintigraphy in the diagnostic and therapeutic evaluation of retroperitoneal fibrosis: a prospective study.

摘要

Background. Gallium-67 ((67)Ga) scintigraphy may be useful in evaluating patients with retroperitoneal fibrosis (RPF), but a systematic assessment of its value is lacking. Objective. Prospective evaluation of the value of (67)Ga scintigraphy in assessing active RPF disease and in predicting treatment response. Methods. Thirty-four patients with nonmalignant RPF treated with tamoxifen underwent (67)Ga scintigraphy at baseline and - if baseline gallium scan was positive - at 3 months follow-up. Gallium scans were visually scored according to pathologic (67)Ga-uptake compared to normal bone marrow (67)Ga-uptake. Results were correlated with other (follow-up) measurements. Value of (follow-up) (67)Ga scintigraphy in predicting treatment response was also assessed. Results. Gallium scans were positive in 24 patients (71%). Mass thickness was greater in patients with positive gallium scan compared with patients with negative gallium scan (P = 0.006). Visual gallium score correlated with mass thickness (P = 0.006). Visual gallium score decreased significantly following tamoxifen treatment (P < 0.0001). Decrease in visual gallium score correlated with decreases in C-reactive protein and erythrocyte sedimentation rate (P = 0.019) and with decrease in mass thickness (P < 0.01). Positive predicting value (PPV) of positive baseline gallium scan was 0.71; PPV of negative follow-up gallium scan in patients with initial positive scan was 0.89. (67)Ga scintigraphy detected extra-abdominal involvement in one patient and recurrent active disease in two symptomatic patients with normal acute-phase reactants and stable residual mass. Conclusion. (67)Ga scintigraphy is useful in assessing (recurrent) activity of RPF disease and in evaluating treatment response in patients with initial positive gallium scan.