Depreotide scanning in sarcoidosis: a pilot study.
OBJECTIVE
To determine whether sarcoidosis results in uptake on (99m)Tc-labeled depreotide (DP) scintigraphy and to generate preliminary data to guide the development of future trials exploring this imaging modality in sarcoidosis patients.


METHODS
Prospective cohort trial among a convenience sample of patients with sarcoidosis.


METHODS
Tertiary care medical center pulmonary clinic.


METHODS
Subjects in whom sarcoidosis has been diagnosed based on a biopsy revealing nonnecrotizing granulomas.


METHODS
Two hours after IV administration of (99m)Tc-DP, all patients underwent whole-body anterior and posterior planar imaging, followed by thoracic single-photon emission CT scanning. Images were interpreted by two nuclear medicine physicians who were blinded to the patient's clinical status.


RESULTS
The study cohort included 22 subjects (mean [+/- SD] age, 41.3 +/- 9.3 years; 40% female). Approximately half of the cohort had stage I disease determined by chest radiographs (CXRs). The results of (99m)Tc-DP scintigraphy were positive for sarcoidosis in 18 individuals (81.8%; 95% confidence interval, 59.7 to 94.8%). Of the four persons lacking (99m)Tc-DP uptake, all had normalized their CXRs since the time of presentation. In the entire sample, the intraclass correlation between radiographic stage determined by CXR vs that determined by (99m)Tc-DP scintigraphy was robust (kappa = 0.79; p = 0.0005). Among patients with positive (99m)Tc-DP scan findings, the correlation was stronger (kappa = 0.94; p < 0.0001). Flow rates and lung volumes were lower in patients with parenchymal activity on (99m)Tc-DP scintigraphy (mean FEV(1), 68.6 +/- 13.9% predicted vs 84.5 +/- 10.7% predicted, respectively [p = 0.012]; mean FVC, 74.0 +/- 16.0% predicted vs 88.4 +/- 12.7% predicted [p = 0.041]). (99m)Tc-DP scintigraphy correctly identified all sites of known nonpulmonary visceral involvement with sarcoidosis.


CONCLUSIONS
The results of (99m)Tc-DP imaging are often positive in sarcoidosis patients, and correlate with disease stage determined by CXR and pulmonary function. (99m)Tc-DP scintigraphy does not preclude the need for biopsy if this is indicated to confirm the diagnosis of sarcoidosis or to exclude the possibility of malignancy. (99m)Tc-DP scintigraphy merits further study in the evaluation and management of sarcoidosis.
Pulmonary and Critical Care Medicine Service, Walter Reed Army Medical Center, 6900 Georgia Avenue NW, Washington, DC 20307, USA. afshorr@dnamail.com
Andrew F
AF
Shorr
Donald L
DL
Helman
Christopher J
CJ
Lettieri
Jamie L
JL
Montilla
Robert S
RS
Bridwell
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010865:Pilot Projects; D011446:Prospective Studies; D012129:Respiratory Function Tests; D012507:Sarcoidosis / Q000000981:diagnostic imaging*; D013004:Somatostatin / Q000031:analogs & derivatives*; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; D013004:Somatostatin; C444119:technetium Tc 99m depreotide