Role of Tc-99m pertechnetate for remnant scintigraphy post-thyroidectomy.

PURPOSE OF THE REPORT: Current surgical techniques in patients with differentiated thyroid cancer can leave little or no remnant tissue. Coupled with favorable prognostic factors, this subgroup of patients might not require radioablative remnant ablation with Iodine-131 (I-131). Postoperative scanning may help to identify this subgroup, however low dose I-131 can lead to stunning and suboptimal response to ablative therapy. Iodine-123 (I-123) can be used but is expensive and supply can be limited. We investigate technetium-99m pertechnetate (pertechnetate) as a potential alternative for remnant scintigraphy post-thyroidectomy. MATERIALS AND METHODS: Seventy consecutive post-total-thyroidectomy patients were evaluated retrospectively. Preablative pertechnetate scans of the thyroid bed were viewed blindly then directly compared with postablative I-131 scans. RESULTS: For patients with unequivocally positive pertechnetate uptake, the sensitivity was 81% (patients), 61% (sites), and the PPV was high (100% patients, 95% sites). In patients with either definite or equivocal pertechnetate uptake, the sensitivity was 90% (patients), 68% (sites), and the PPV was also high (100% patients, 81% sites). CONCLUSIONS: Pertechnetate had reasonable correlation with postablative I-131 scans with a moderately high sensitivity and a very high PPV. A positive pertechnetate scan is therefore sufficient to guide progression to I-131 ablation in most patients. When the scan is equivocal or negative, diagnostic imaging with radioiodine may be required. Pertechnetate scintigraphy may be of particular benefit if it is considered desirable to avoid I-131 in post-thyroidectomy remnant imaging.

Black-white differences in risk of developing retinopathy among individuals with type 2 diabetes.

OBJECTIVE: To assess racial differences in risk of developing retinopathy among individuals with type 2 diabetes, after taking into account differences in the distribution of risk factors for retinopathy. RESEARCH DESIGN AND METHODS: The participants were 105 individuals with type 2 diabetes, aged 40-69 years, who had no evidence of retinopathy at the time of a diabetic eye disease screening project. After an average of 4 years of follow-up, the subjects were reevaluated using nonmydriatic funds photography. RESULTS: Retinopathy occurred more often among black than white participants (50 vs. 19%). This difference could not be explained by differences in risk factors for retinopathy or potential confounders (odds ratio [95% CI] 2.96 [1.00-8.78] after adjustment for level of glycosylated hemoglobin, systolic blood pressure, type of diabetes treatment, and sex). CONCLUSIONS: These results are consistent with the concept that racial differences in risk of developing retinopathy exist among individuals with type 2 diabetes and that these differences may be caused by differential (genetic) susceptibility to the adverse effects of increased levels of blood glucose and/or blood pressure. Discovery of the etiology of this differential susceptibility would allows us to identify and target secondary prevention efforts to individuals with type 2 diabetes who are at increased risk of retinopathy.

Progression of pseudovitelliform macular dystrophy.

Pseudovitelliform macular dystrophy is a dominantly inherited macular disorder. It is characterized by the presence of horizontally oval yellowish deposits within the maculas that are approximately one-third disc diameter in size. As classically described, progression of the lesions over a follow-up period of as long as six years has not been described and the prognosis for retention of good visual function is excellent. We report the ophthalmoscopic appearance of six eyes of three patients from a very subtle alteration of macular pigmentation to severe disruption of macular architecture, and demonstrate in one of our patients drastic deterioration in both ophthalmoscopic appearance and visual function over a three-year period of follow-up. The prognosis for retention of good vision in this disorder must include the possibility of the eventual development of severe visual impairment.

Diagnostic vitrectomy in metastatic breast carcinoma in the vitreous.

Pars plana vitrectomy was employed to establish the diagnosis of intraocular carcinoma in a 72-year-old woman with a history of breast carcinoma and cerebral astrocytoma. Cytologic study of the material obtained from the vitreous cavity established the diagnosis of metastatic breast carcinoma, and this was later confirmed by study of the eyes obtained postmortem. The clinical and cytologic features of the ocular metastasis of breast carcinoma are presented.

Optic neuropathy due to brain abscess.

A 26-year-old man went blind as part of a multifocal central nervous system disease. Bilateral optic nerve head pallor developed four weeks later. There had been no papilledema. In this setting, the appearance of optic atrophy without preceding papilledema in part led to the clinical diagnosis of severe disseminated encephalomyelitis. At autopsy multiple brain abscesses were found, including an area of inflammation within the chiasm.