Detection of the sentinel node in breast carcinoma using method of a single subcutaneous injection of radiopharmaceutical

The objective of this work is retrospective evaluation of results of the intraoperative detection of sentinel node in breast carcinoma after a single subcutaneous injection of radiopharmaceutical (RF) within a two-day protocol. From May/2001 to June/2002, lymphoscintigraphy of the sentinel node (SN) and its subsequent radioguided intraoperative detection (RGS) was performed in 43 women having stage T1-T2, N0 breast carcinoma. The static scans in the anterior and relevant lateral projections were performed using a gamma camera at approximately 30-minute intervals after the subcutaneous administration of 15 MBq 99mTc Senti-Scint, until the SN was displayed. The localization of the SN was marked on the overlying skin with a water-resistant permanent marker in 1-2 projections. RGS was accessed within 18-24 hours after the injection of the RF and all patients underwent an axillary dissection. The SN was detected in all patients, and in all cases was localized in the ipsilateral axilla. In 26 patients (60%), no metastatic process was found either in the SN or in any other axillary node. However, in one node, deposits of the carcinoma were detected in surrounding fatty tissue with propagation along the vessels and nerve. In 16 patients (37%), metastases in the SN were proved, in 7 cases (16%), a metastatic process was proved at the same time even in further lymph nodes. A number of false negative findings (5.8%) is consistent with the literature data. The method fails in the detection of intramammary localized SNs.

Improved prediction of therapeutic absorbed doses of radioiodine in the treatment of thyroid carcinoma

We proposed an alternative to a monoexponential model of radioiodine kinetics to obtain a more accurate estimate of absorbed doses to postsurgical thyroid remnants. We suggested that part of the difference between the predicted and the actually absorbed therapeutic doses of (131)I, usually explained by radiation damage of thyroid cells, can be attributed to errors resulting from inadequate sampling of data and oversimplified modeling.

METHODS

A standard monoexponential model and alternative biphasic model (incorporating both radioiodine uptake and clearance) were used on 2 sets of patient data to fit time-activity measurements after administration of diagnostic and therapeutic activities of radioiodine. One set of data consisted of 633 records of routine measurements, and the second set consisted of 71 prospectively collected records with measurements performed more frequently and for a longer time. The time-activity curves derived from the 2 models were used to calculate residence times for diagnostic and therapeutic activities of (131)I, and the respective residence times were compared using the paired t test. Errors of fitting and prediction of therapeutic time-activity data were also calculated.

RESULTS

With both models, a statistically significant difference (P < 0.01) was found between residence times after diagnostic administration of (131)I and residence times after therapeutic administration of (131)I. However, the effects of biphasic modeling and of improved sampling substantially reduced the difference (P < 0.01). Errors of fitting and prediction were smaller with the biphasic model than with the monoexponential model (P < 0.01).

CONCLUSION

The biphasic model more accurately predicts (131)I kinetics when applied to measurements in the short interval after diagnostic administration of radioiodine. The minimum requirement for the biphasic model is measurement twice a day at intervals > 6 h for at least 3 d after administration.

In vitro autoreactivity against skin in rheumatoid arthritis: are peripheral blood mononuclear cells of patients with rheumatoid arthritis able to lyze autologous keratinocytes?

An in vitro skin explant model was originally developed to predict the occurrence and severity of acute graft-versus-host disease in allogeneic hematopoietic stem cell transplants. In previous studies we reported that peripheral blood mononuclear cells of patients with rheumatoid arthritis were able to induce graft-versus-host-like histopathological changes when co-cultured in vitro with autologous skin explants. The aim of the present study was to verify if observed skin damage was really of autoimmune origin. Using a 51chromium release cytotoxic assay we found that peripheral blood mononuclear cells of patients lyzed autologous keratinocytes (n=5 patients with rheumatoid arthritis) but not autologous lymphoblasts (n=4 with rheumatoid arthritis, n=8 patients with juvenile idiopathic arthritis). No specific lysis of keratinocytes or lymphoblasts was observed in healthy controls (n=15). We hypothesize that autologous peripheral blood mononuclear cells might recognize similar autoantigen(s) expressed on epidermal cells, which gives rise to an autoimmune response in the synovium.

Positive thyroid cancer scintigraphy using technetium-99m methoxyisobutylisonitrile

The aim of the study was to evaluate the possibility of detecting thyroid cancer recurrences without the need for withdrawal of thyroid suppressive treatment. Upper-body or whole-body scintigraphy was performed in a group of 200 patients evaluated for differentiated thyroid cancers in 1993 and 1994 using technetium-99m sestamibi. Scans were performed 20-30min following i.v. administration of 500MBq of 99mTc-methoxyisobutylisonitrile (MIBI). Bone and lung metastases were detected with very high sensitivity and specificity, with a very high predictive value of negative results and a somewhat lower predictive value of positive results. The sensitivity and specificity of findings in the neck were lower but the predictive value of negative results was high. Whole-body scans with 99mTc-MIBI are a useful tool in the follow-up of patients with differentiated thyroid cancer, for the detection of distant metastatic lesions.

Positive thyroid cancer scintigraphy using 99Tcm-tetrofosmin (Myoview): a preliminary report

99Tcm-tetrofosmin imaging was performed in 23 thyroid cancer patients and compared with whole-body 131I scans, neck ultrasonography and plasma thyroglobulin levels. Of 22 patients with differentiated thyroid cancer, 8 showed identical images on 131I scan and tetrofosmin; 1 patient with medullary cancer had identical images with 99Tcm-DMSA and 99Tcm-tetrofosmin, the findings being confirmed by sonography. The potential usefulness of 99Tcm-tetrofosmin imaging in the follow-up of thyroid cancers is discussed.

Osteocalcin in congenital adrenal hyperplasia

Osteocalcin in the serum reflects bone turnover. It is known that prolonged therapy with glucocorticoids inhibits bone turnover. The aim of this study was to evaluate the osteocalcin level in children with congenital adrenal hyperplasia treated by glucocorticoids and mineralocorticoids and to assess the influence of 1,25(OH)2D3. The subjects were 75 children with congenital adrenal hyperplasia, aged 1-18 years, treated with glucocorticoids and mineralocorticoids in substitution doses from birth. These children demonstrated low levels of osteocalcin and alkaline phosphatase, whereas calcium and phosphate were in the normal ranges. Despite these abnormalities, no osteoporosis was detectable and a normal growth rate was confirmed, most probably because of higher levels of androgens; 17-OH progesterone averaged 11.8 nmol/l. After treatment with 1,25(OH)2D3, the osteocalcin levels increased, followed later by increases of alkaline phosphatase and bone isoenzyme.

[Development of various technical modifications in diagnostic sonography of the thyroid gland and their possible clinical applications]

The authors evaluate twenty-five years application of ultrasound in the diagnosis of thyrroid disease focused on the technical development and closely associated possibilities of morphological and functional interpretations of sonographic findings. They discuss future perspectives of the use of ultrasound in thryology, in particular duplex sonography and coloured coded Doppler sonography. Attention is devoted to perspectives aimed aspiration biopsy under sonographic control and extension of its indications. They discuss the possible asset of further in this country so far not applied modifications of diagnostic sonography in thyrology, incl. the development of mathematical and statistical methods of evaluation of the echogenity and echotexture of thyroid tissue.

[Subclinical hypothyroidism]

Subclinical hypothyroidism was detected in 5.7% of 853 patients referred for ambulatory examination to a department in Prague. In patients referred with a mild degree of subclinical hypothyroidism with an evaluated level of thyrotropic hormone in serum (TSH) no significant deviations of serum thyroxine and triiodothyronine (T4 and T3) were found nor different values of the Achilles tendon reflex time, as compared with patients with normal thyroid function. In case of a more marked grade of subclinical hypothyroidism with an elevated TSH level without stimulation the patients have on average significantly lower T4 vales, significantly longer Achilles tendon reflex times and preejection stage of left ventricular contraction, and of Rodbard's Q-Kd interval (Q-Kd) than euthyroid patients. The values are, however, still within the reference range for normal function and in individual cases cannot be decisive for establishment of the diagnosis. The authors discuss the differential diagnosis and views on treatment of this disease.

Analysis of the 1,4-benzodiazepines by methods based on hydrolysis

The analytical applications of the hydrolysis of 1,4-benzodiazepines to the corresponding benzophenone derivatives are reviewed according to the analytical methods used for their final determination. The scope and limitations of the individual methods for the hydrolysis products are discussed: Colour reactions, photometry, fluorimetry, thin-layer chromatography, gas chromatography and high-performance liquid chromatography. Published data on the kinetic parameters and mechanisms are summarized in an attempt to explain the problems involved in exploiting this reaction for analytical applications.