No abstract

Basic recommendations for follow-up utilizing OPG/CPA results are as follows: Grade 1: Repeat studies in 12 months in the absence of specific focal TIAs or increase of bifurcation level bruit. Grade 2: Serial studies in 6 to 12 months in the absence of focal TIAs which provide their own indications for evaluation. If stability is established, 12-month interval testing is adequate. Grade 3: Serial studies in 3 to 6 months until a progression trend is established. Anticipation of major surgery with possible hypotension or severe blood loss is an indication for arteriography and possible endarterectomy. Grade 4: If repeat studies confirm grade 4 status, prophylactic carotid arteriography and endarterectomy should be seriously considered. If surgery is not employed, repeat OPG/CPA evaluation at 2 to 4 month intervals detects further progression toward total occlusion. Grade 5: Indications for arteriography in anticipation of surgery are tempered by the lower probability (30%) of a surgically correctable stenosis and the clinical status of the patient. In conclusion, we feel that OPG/CPA represents one valid means of noninvasively evaluating the presence and underlying hemodynamic significance of an asymptomatic bruit with sufficient reliability to justify angiography and prophylactic carotid endarterectomy on the basis of appropriate findings.

Medullary carcinoma (MC) of the thyroid, in contrast to papillary-follicular carcinoma, fails to concentrate iodine and thus has not been treated with radioactive iodine. We have successfully treated a 16-yr-old Mexican-American girl with residual MC after maximal thyroidectomy (Tx), utilizing radioiodine (131I) to deliver radiation to residual follicular cells in the tumor bed. Immediately after Tx, plasma thyrocalcitonin levels before and during calcium infusion were all elevated (640--1200 pg/ml). 131I (150 mCi) was administered 12 days after Tx after four daily im injections of bovine TSH. Three months after 131I therapy, thyrocalcitonin levels before and during calcium infusion were all normal (less than 50 pg/ml). Ten months after 131I therapy, thyrocalcitonin levels before and after iv pentagastrin were all normal (less than 60 pg/ml). These results suggest that parafollicular cells are radiosensitive, and that therapeutic levels of radiation can be delivered to these cells after Tx if iodine trapping by the remaining follicular cells is enhanced by high levels of circulating TSH. 131I may be the therapy of choice for MC after Tx, if disease has not spread beyond the area proximate to the thyroid gland.