[Radioiodine therapy of functional autonomy of the thyroid gland. Treatment results in view of pretreatment scintigraphic diagnosis and early response of triiodothyronine levels to treatment]. / Die Radiojodtherapie der funktionellen Schilddrüsenautonomie. Behandlungsergebnisse unter Berücksichtigung der Autonomieform und des frühen posttherapeutischen Trijodthyroninspiegels.

AIM: The goal of this retrospective study was to evaluate the results of radioiodine therapy of thyroid autonomy with respect to the underlying scintigraphic pattern, administered I-131 doses and pretherapeutic Tc-99m and I-131 uptake. Furthermore, early post-therapeutic free triiodothyronine (FT3) levels were measured during the first 6 weeks after radioiodine therapy with respect to a FT3-increase. PATIENTS AND METHODS: Thyroid autonomy in 632 patients was followed for at least 3 months (mean 10.9 months). The patients were divided into several groups based on scintigraphic pattern of unifocal (UA), a multifocal (MFA), a focal/disseminated (FDA) and a disseminated (DA) autonomy. The early effects of therapy on thyroid function were assessed by evaluation of FT3 values of 786 patients during the 1st, 2nd, 3rd, 4th and 6th week after therapy. RESULTS: Successful elimination of thyroid autonomy as defined by normalization of FT3 and TSH levels was observed in 92.1% (582/632) of the patients. In 2.2% (14/632) of the patients, immunogenic hyperthyroidism following I-131 therapy was observed. There was no significant difference in the success rates in patients with UA and MFA of 94.9% and 96.1%, respectively, using similar target doses based on the amount of autonomous tissue. The success rate in MFA (96.6%) was similar if target dose was calculated based on the volume of the whole thyroid gland. Compared to MFA (96.6%), however, FDA and DA were associated with significantly lower success rate with 82.7% and 75.5%, respectively, although the target doses were not significantly different. Considering the quantitative Tc-99m uptake prior to therapy, there was no significant difference in the success rate for Tc-99m uptake < or = 3% and > 3%, while the success rate in patients with I-131 uptake of < or = 50% was significantly higher (p = 0.032) than in those with an uptake of > 50%. The determination of FT3 levels during the first 6 weeks after radioiodine therapy revealed a dependence of the FT3 decrease and FT3 increase on the scintigraphic pattern and thyroid function. Patients with FDA and DA with hyperthyroidism showed an increase of FT3 (> 2 to 14.7 pmol/l) in 11 to 18% of the cases, during the first 2 weeks after therapy which occurred significantly more frequently in patients with FDA and DA than in UA and MFA. A similar increase in FT3 level in patients with FDA and DA compared to patients with UA and MFA was observed in 317 patients with euthyroid pretherapeutic hormone levels. A decrease in FT3 level following radioiodine therapy was observed significantly more often and earlier in patients with UA and MFA with hyperthyroid values than in patients with FDA and DA during the first 6 posttherapeutic weeks. Concerning patients with euthyroid FT3 levels, the decrease in FT3 level was observed significantly more frequently in patients with UA and MFA only after 6 weeks following radioiodine therapy. CONCLUSION: In contrast to the multifocal autonomy (MFA), the target dose of 150 to 200 Gy based on total thyroid volume did not result in a comparably high success rate of approximately 95% in disseminated and focal/disseminated types of thyroid autonomy. Therefore, an increase of target dose of 200 to 300 Gy is recommended. The transient FT3 increase particularly observed in FDA and DA in the first weeks following radioiodine therapy makes short-term controls of thyroid function necessary, especially in patients with cardiac risk, in order to initiate necessary therapy.

[Occurrence of immune hyperthyroidism after radioiodine therapy of autonomous goiter]. / Zum Auftreten einer Immunhyperthyreose nach Radiojodtherapie von Schilddrüsenautonomien.

AIM: The goal of the study was to examine the prevalence of Graves' disease following I-131 treatment of autonomous goiter with special regard to pretreatment scintigraphic patterns. PATIENTS AND METHOD: Pre- and posttreatment in-vitro and in-vivo parameters were studied in 375 consecutive patients treated with I-131 therapy for nodular or diffuse autonomous goiter. All patients included were within ambulant control for at least 2.5 months following treatment. According to the pretreatment Tc-99m pertechnetate scan 59% (220/375) had multifocal (MF), 23% (86/375) unifocal (UF), 10% (38/375) mixed focal-disseminated (FD) and 8% (31/375) disseminated (D) scintigraphic patterns. RESULTS: In 93.9% (352/375), the autonomous tissue was totally, in 2.1% (8/375) partially and in 1.6% (6/375) insufficiently eliminated. In 2.4% (9/375) a relapse of hyperthyroidism was observed 2 to 10 months following I-131 therapy. In 8 patients a relapse of hyperthyroidism was accompanied or followed by an elevation of the previously non-elevated TSH-receptor antibody (TRAb) level and in 1 patient by an TRAb increase to the upper borderline range implicating Graves' disease. With the prevalence of Graves' disease following I-131 therapy a statistically significant difference in pretreatment Tc-99m pertechnetate scintigraphic patterns was found: 0% of unifocal (0/86) or multifocal (0/220), however 18% (7/38) of focal-disseminated and 7% (2/31) of disseminated scintigraphic patterns. From the 366 patients without relapse of hyperthyroidism 2 (MF) had elevated pre- and posttreatment TRAb levels and 3 (D) had elevated TRAb levels for the first time after I-131 therapy. CONCLUSION: There is a low overall prevalence (2.4%) of Graves' disease following I-131 therapy for nodular or diffuse autonomous goiter. However, the prevalence of posttreatment Graves' disease is highly dependent upon pretreatment scintigraphic patterns exhibiting focal-disseminated or disseminated patterns.

[Experimental studies of healing and antigenicity of sterilized bone transplants]. / Experimentelle Untersuchungen zur Einheilung und Antigenität von sterilisierten Knochentransplantaten.

UNLABELLED: The aim of our study was to observe the incorporation and induced immune response of sterilized bone allografts. We performed an orthotopical tibial segment transplantation using two different inbred rat strains. We compared irradiated (25 kGy), autoclaved (134 degrees C) and cryopreserved (-80 degrees C) bone grafts. The observation took place 6 and 12 weeks post-operatively. RESULTS: The incorporation of irradiated grafts took longer than cryopreserved transplants. Autoclaved grafts were not incorporated and only bridged by new callus formation. A cell-mediated immune response against the cryopreserved grafts could be demonstrated. Irradiated grafts induced a major immune response; autoclaved grafts did not. CONCLUSION: There seems to be a correlation between loss of antigenicity and failure of graft incorporation. Therefore, it seems probable, that some bone antigenicity is necessary for the induction of cellular mechanisms during graft incorporation.

[Bone healing--an immunoreactive process?]. / Die Knochenheilung--ein immunreaktiver Vorgang?

Cell mediated immune reactions, demonstrated by leukocyte migration assay and histological analysis of spleen and lymph nodes, could be observed after fresh autografting of cortical segments in rats. The detected immune answer showed a bone-specific reaction pattern. In consideration of the temporal correlation of the observed immune reactions and the histological signs of graft incorporation, a connection of bone healing and immune system may be possible.