For the estimation of goiter volume, MR imaging has low intra- and interobserver variations. In contrast, the determination of tracheal dimensions using MR imaging has a high variability and, thus, is imprecise. Sonography significantly underestimates thyroid volume compared with MR imaging in patients with a large goiter.

Some patients with very large goiters (>150 mL) are not candidates for surgery. We evaluated the feasibility of high dose 131I in such patients. Twenty-three patients (2 men and 21 women; median age, 67 yr; range, 42-86 yr) with very large goiter (8 toxic) were treated with calculated high dose 131I [median, 2281 megabecquerels (61.6 mCi); range, 988-4620 megabecquerels (26.7-124.9 mCi)]. During the 12-month observation period, goiter reduction and tracheal anatomy were monitored by magnetic resonance imaging, and the respiratory capacity was monitored by pulmonary function tests. Five patients (22%) developed hypothyroidism. Thyroid volumes were at baseline, after 1 week, and after 1 yr [mean +/- SEM, 311 +/- 28, 314 +/- 26 (P = NS), and 215 +/- 26 (P < 0.01) mL]. The relative changes 1 week after therapy ranged from -14.1% to 15.3%. After 1 yr the mean size was reduced by 33.9% (range, 13.5-61.4%). Only the initial goiter size showed a significant negative correlation to the percent reduction. The smallest cross-sectional area of the trachea decreased 9.2% within 1 week after treatment, but eventually emerged with a 17.9% larger area [mean +/- SEM, 84.3 +/- 4.8, 75.5 +/- 5.1 (P < 0.01), and 98.2 +/- 6.0 (P < 0.01) mm2]. The inspiratory parameter, FIF50%, improved after an initial insignificant decline [baseline therapy, after 1 week, after 3 months, and after 1 yr (mean +/- SEM), 2.37 +/- 0.24, 2.20 +/- 0.21 (P = NS), 2.51 +/- 0.23 (P = NS), and 2.76 +/- 0.25 (P = 0.01) L/s]. FIF50% correlated significantly with the smallest cross-sectional tracheal area (baseline, 1 week, and 1 yr: r = 0.74; P < 0.001, r = 0.63; P < 0.005, and r = 0.46; P < 0.05). Changes in tracheal anatomy did not correlate with changes in either lung dynamics or goiter size. In conclusion, very large goiters can be reduced by a third, on the average, with high dose 131I therapy without any initial clinically significant tracheal compression. Tracheal cross-sectional area as well as pulmonary inspiratory capacity improve. No serious adverse effects are seen.

Most often thyroidectomy is recommended in patients with large goiters. However, high-dose (131)I therapy may be used in case of contraindications to surgery. Large goiters are often partially located in the mediastinum. The aim of this study was to evaluate the impact of (131)I therapy on the cervical and the substernal goiter volume, separately. Fourteen patients (median age, 69 years; range, 52-86 years) with a large multinodular goiter (three hyperthyroid) and with a substernal extension greater than 15 mL were included. T1-weighted magnetic resonance (MR) estimates of the thyroid volume in the cervical and substernal compartments were obtained before and 1 year after high-dose (131)I therapy. The total goiter volumes ranged from 182 to 685 mL. The median substernal volume was 66 mL (fraction of total volume, 17.6%; range, 8.0%-78.9%). One year after treatment, the median substernal goiter volume was reduced by 29.2% (range, -6.1%-59.4%, mean: 26.1% +/- 6.0%), and the cervical goiter volume by 30.3% (range, 6.0%-75.4%, mean, 35.6 +/- 5.6%) compared to baseline values; p = 0.25 for difference in a regional effect. The volume reduction was unrelated to initial substernal goiter size. Likewise, deterioration of the inspiratory capacity did not correlate with the magnitude of the substernal goiter extension. In conclusion, high-dose (131)I therapy seems as effective in reducing the substernal as the cervical goiter volume. However, because the overall effect is modest, this therapy should primarily be considered for the patient with a high surgical risk.

Summary.The absorption rate of rapid acting (soluble) insulin is slow from the subcutaneous tissue of the thigh compared to intramuscular injection into the thigh and s. c. injection into the abdominal wall. The aim of the study was to evaluate the impact of soluble insulin injected either intramuscularly into the thigh (IMT), s. c. into the abdominal wall (SCA) or s.c. into the thigh (SCT) on glycaemic control in Type 1 (insulin-dependent) diabetic outpatients treated with the basal bolus insulin delivery regimen. Fifty-five, C-peptide negative Type 1 diabetic outpatients were included in a randomised 3-month intervention study. The insulin doses were adjusted frequently by blinded observers based on the patients' self-monitored blood glucose values and reported hypoglycaemic episodes. The serum fructosamine value was within normal limits in three patients in the IMT group, in six patients in the SCA group and in none of the patients in the SCT group following the intervention period (p < 0.01). However, the difference in mean serum fructosamine values did not reach statistical significance (IMT: 1.24 retool/1 (95 % confidence interval; 1.17 to 1.31), SCA: 1.25 mmol/1 (1.18 to 1.32), SCT: 1.34 mmol/1 (1.26 to 1.41), (p = 0.09)). Blood glucose excursions were larger in the SCT group than in the SCA and IMT group from post-lunch to pre-dinner measurements and from pre-to post-dinner measurements. A higher number of measured low nocturnal blood glucose values (less than 4 mmol/1) was observed in the SCT group (34 of 85) than in the IMT (14 of 64) and SCA (21 of 81) group (p < 0.05). Three patients in the IMT group, two in the SCA group, and seven in the SCT group experienced severe hypoglycaemic episodes (p = 0.14). In conclusion s. c. injection of soluble insulin into the abdominal wall is preferable compared to s. c. injection into the thigh in the basal bolus insulin delivery regimen. Furthermore, soluble insulin injection s. c. into the thigh during daytime has important clinical implications for the development of nocturnal hypoglycaemia independently of the NPH insulin injection at bedtime. Key words: Insulin pharmacokinetics, intramuscular insulininjection, subcutaneous insulin injection, blood glucose control, nocturnal hypoglycaemia.The multiple insulin injection regimen (basal bolus insulin delivery regimen) is based on injections of soluble (rapid acting) insulin at mealtimes and injections of NPH (intermediate acting) insulin at bedtime. The purpose of this insulin regimen is to mimic the normal diurnal plasma insulin profile [1]. Thus, the purpose of the bolus component is to provide insulin delivery adequately timed to the absorption of the meal, whereas the purpose of the basal component is to provide adequate insulinisation during the night time and between meals. Obviously, insulin delivery depends on the absorption rate of the injected insulin and this has been demonstrated to vary considerably between different anatomical regions [2][3][4][5][6][7][8][9][10][11][12].It has been shown, that the p...

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