title: Technetium tc 99m-labeled red blood cells in the preoperative diagnosis of cavernous hemangioma and other vascular orbital tumors.
abstract: OBJECTIVE
  To evaluate technetium Tc 99m (99mTc) red blood cell scintigraphy as a diagnostic tool for orbital cavernous hemangioma and to differentiate between orbital masses on the basis of their vascularization.
  
  
  METHODS
  We performed 99mTc red blood cell scintigraphy on 23 patients (8 female and 15 male; mean age, 47 years) affected by an orbital mass previously revealed with computed tomography (CT) and magnetic resonance imaging (MRI) and suggesting cavernous hemangioma. In our diagnosis, we considered the orbital increase delayed uptake with the typical scintigraphic pattern known as perfusion blood pool mismatch. The patients underwent biopsy or surgical treatment with transconjunctival cryosurgical extraction when possible.
  
  
  RESULTS
  Single-photon emission tomography (SPET) showed intense focal uptake in the orbit corresponding to radiologic findings in 11 patients who underwent surgical treatment and pathologic evaluation (9 cavernous hemangiomas, 1 hemangiopericytoma, and 1 lymphangioma). Clinical or histologic examination of the remaining 22 patients revealed the presence of 5 lymphoid pseudotumors, 2 lymphomas, 2 pleomorphic adenomas of the lacrimal gland, 1 astrocytoma, 1 ophthalmic vein thrombosis, and 1 orbital varix.
  
  
  CONCLUSIONS
  The confirmation of the preoperative diagnosis by 99mTc red blood cell scintigraphy shows that this technique is a reliable tool for differentiating cavernous hemangiomas from other orbital masses (sensitivity, 100%; specificity, 86%) when ultrasound, CT, and MRI are not diagnostic. Unfortunately, 99mTc red blood cell scintigraphy results were positive in 1 patient with hemangiopericytoma and 1 patient with lymphangioma, which showed increased uptake in the lesion on SPET images because of the vascular nature of these tumors. Therefore, in these cases, the SPET images have to be integrated with data regarding clinical preoperative evaluation and CT scans or MRI studies. On the basis of our study, a complete diagnostic picture, CT scans or MRI studies, and scintigraphic patterns can establish the preoperative diagnosis of vascular orbital tumors such as cavernous hemangioma, adult-type lymphangioma, and hemangiopericytoma.
authors.affiliation: Department of Ophthalmology, University of Siena, Siena, Italy. enniopolito@virgilio.it
authors.forename: Ennio
authors.initials: E
authors.lastname: Polito
authors.forename: Luca
authors.initials: L
authors.lastname: Burroni
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pichierri
authors.forename: Antonio
authors.initials: A
authors.lastname: Loffredo
authors.forename: Angelo G
authors.initials: AG
authors.lastname: Vattimo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003937:Diagnosis, Differential; D004912:Erythrocytes / Q000000981:diagnostic imaging*; D005260:Female; D006392:Hemangioma, Cavernous / Q000098:blood supply / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009918:Orbital Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D011300:Preoperative Care; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D013670:Sodium Pertechnetate Tc 99m; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m