Vinko Marković

Planning of 131I Therapy for Graves Disease Based on the Radiation Dose to Thyroid Follicular Cells

We evaluated the effects on the absorbed dose to thyroid follicular cells of self-absorption of 131I radiation (specifically, β-rays) in the follicular colloid. Methods: Thyroid follicles were modeled as colloid-filled spheres, containing a uniform concentration of 131I and surrounded by a concentric monolayer of cells. Assuming close packing of identical follicles, we used Monte Carlo simulation to assess the absorbed dose to follicular cells. Results: Because of β-ray self-absorption in colloidal spheres with radii larger than 50 μm, the absorbed dose to follicular cells is less than the average thyroid absorbed dose. Conclusion: For the same thyroid mass, radioiodine thyroid uptake, and effective half-life, patients with follicles with colloidal sphere radii of 100, 200, 300, and 400 μm should be administered 9%, 15%, 21%, and 30% more 131I, respectively, than patients with colloidal sphere radii of less than 50 μm, to yield the same absorbed dose to follicular cells.

Spirometric disorders in women with genital descensus

Background. We hypothesized that abnormalities in connective tissue, found in women with genital descensus, could impact their pulmonary function.

Izražajnost ciklina D1, RET i p27 u papilarnom mikrokarcinomu štitne žlijezde

Th e aim of the study was to determine the influence of RET, p27 and cyclin D1 on regional lymph node metastases in papillary microcarcinoma. The analysis included 70 patients with papillary thyroid microcarcinoma that underwent surgery at Split University Hospital Center between 1999 and 2001. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissue by the RET, p27 and cyclin D1 antibodies. Quantification was based on the intensity and distribution of nuclear staining, dividing tumors into those that showed expression (expressors) and those that showed no expression (non-expressors). Univariate analysis using χ²-test and Fisher exact test was performed with the level of statistical significance set at p<0.05. There was no statistically significant difference in the incidence of metastases according to the expression or non-expression of RET mutation (χ²-test: p=0.459; Fisher exact test: p=0.672). Among 25 cases with cyclin D1 expression, 6 had metastases, whereas only 2 of 45 cases with no cyclin D expression had metastases (χ²-test: p=0.014; Fisher exact test: p=0.021), indicating that the expression of cyclin D1 is not crucial for the development of metastases in lymph nodes. In contrast, analysis of p27 expression showed it to be significantly associated with lymph node metastasis because 3 of 45 patients with p27 expression had metastases, indicating a statistically significant correlation between p27 expression and lymph node metastases (χ²-test: p=0.093; Fisher exact test: p=0.124). This study confirmed the importance of the evaluation of RET, p27 and cyclin D1 expression and demonstrated the validity of their application in the assessment of microcarcinoma behavior.

Are we estimating the adverse effects of shock-wave lithotripsy on a faulty scale?

The adverse effect of shock-wave lithotripsy (SWL) for renal stones on blood pressure is currently defined as its post-treatment increase. On the contrary, we hypothesize that even mild, unilateral renal obstruction initiates an increase in blood pressure. Then, in absence of treatment-induced injury, the stone removal should decrease the blood pressure. We derived the formula to assess the expected change in the mean arterial pressure following relief of renal obstruction without affecting the kidney functions. The predictions were well replicated in the cohort of patients with renal stone treated with parenchyma-saving open surgery, with 6.4 mmHg decrease at 3 months. On the contrary, in SWL cohort, instead of the expected 4.7 mmHg decrease, the blood pressure was unchanged. In conclusion, the absence of decrease in blood pressure is a very common adverse effect of SWL, leading to an epidemiologically significant increase in the risk of arterial vascular events.

Dual ectopic thyroid gland: sonography and scintigraphy of lingual and sublingual thyroid.

Dual ectopic lingual and sublingual thyroid gland is an extraordinarily rare condition. We present 1 patient with subclinical hypothyroidism. The clinical examination revealed that the thyroid gland was not palpable in its usual cervical location, whereas ultrasonography confirmed an empty thyroid bed without any ectopic thyroid tissue in the rest of the neck. The final diagnosis of dual ectopic lingual and sublingual thyroid was established by ultrasound examination through the mouth floor and confirmed by scintigraphy and CT thereafter.

Preoperative Tc-99m-pertechnetate scan visualization of gross neck metastases from microcarcinoma papillare and another papillary carcinoma of tall cell variant scintigraphically presented like small warm nodule in Graves disease patient.

Purpose: Preoperative scintigraphic visualization of metastases from well-differentiated thyroid microcarcinoma in patients with Graves disease is extremely rare, as is the scintigraphic visualization of poorly differentiated thyroid carcinoma as a warm nodule. We present a patient with Graves disease and both of these rare entities. Case Report: A 47-year-old woman complained of a growing left-side neck mass and symptoms of thyrotoxicosis. On clinical examination, the thyroid was palpable without discernible nodularity, while the left side of the neck was occupied by 3 gross, painless nodules. She also had signs of thyrotoxicosis and biochemical parameters of Graves hyperthyroidism. Ultrasound examination showed moderately hypoechogenic thyroid with a small hypoechogenic nodule in the upper pole of the left lobe and 3 gross, almost normoechogenic nodules on the left side of the neck. On Tc-99m-pertechnetate pinhole scintigraphy there was a small, warm nodule in the upper pole of the left lobe and 3 gross metastatic nodules on the left side of the neck. Fine needle aspiration of the neck nodules was consistent with metastases from thyroid papillary carcinoma. After thyrostatic preparation a total thyroidectomy with left modified radical neck dissection was done. Results and Conclusion: Histopathologic examination disclosed 2 carcinomas in the left thyroid lobe. One of them was a tall cell variant of papillary carcinoma in the upper pole of the left lobe that measured 5 mm and corresponded to the small warm nodule, and the second one was a classic form of papillary microcarcinoma that measured 2 mm. Metastases accrued from the classic form of papillary microcarcinoma. Although the patient had 2 thyroid carcinomas, one with metastases and the other of more aggressive form, which is consistent with advanced stage and aggressiveness, she is now disease-free, 4 years after the operation and radioiodine ablation.

Determinants of 131I radiation dose to thyroid follicular cells

We argued that modeling the thyroid as composed of identical follicles, packed as inside the cubes that are aligned side to side is unrealistic since this leaves too much space between diagonal neighbors and in reality these spaces are occupied by relatively small follicles. This assumption leads to underestimation of self-absorption of 131I radiation in coloidal lumens of the thyroid follicles. We conclude that the degree of intrathyroidal inhomogeneity of 131I beta radiation dose may be larger than estimated by Hindie et al. due to close packing of follicles, which is especially important in cases of relatively large follicles.

Gastrointestinal Lymphorrhea Diagnosed by Exercise Lymphoscintigraphy

Lymphoscintigraphy is not considered as a first line diagnostic procedure in abdominal or thoracic lymphorrhea of various origin. We report a patient with lymphangiectasia in whom posttraumatic lymphorrhea was diagnosed by lymphoscintigraphy only after third attempt when we applied pushups exercise with the aim to raise venous pressure and thus provoke lymph backflow in ductus thoracicus and enteric lymphytics. Lymphorrhea was clearly visible in colon ascendens and colon transversum on 9h planar scintigram. We propose exercise lymphoscintigraphy with exercise tailored to individual patients possibility before each lymphoscintigram to enhance lymphorrhea detection in patients with suspected lymph leakage.

P2. VATS sentinel node biopsy reduces the need for systematic mediastinal lymphadenectomy in early stage NSCLC

Objective Systematic mediastinal lymphadenectomy is still essential for an adequate postoperative staging of non-small cell lung cancer (NSCLC). We tried to investigate the controversial role of sentinel node biopsy (SNB) in early stage NSCLC surgery using videothoracoscopic approach (VATS).

Huge intrathoracic goiter in an asymptomatic patient.

Chest radiography in a 59-year-old woman with a respiratory tract infection revealed a large sharply demarcated intrathoracic mass occupying almost half of the right hemithorax with tracheal deviation to the left (Figure 1). Clinical examination revealed multinodular goiter with substernal extension, precluding examination of the lower pole of the right thyroid lobe. Ultrasound confirmed a multinodular cervical goiter and substernal extension of the right thyroid lobe, with no ability to delineate its lower part. The serum thyrotropin was suppressed with normal serum thyroxine and triiodothyronine. Computed tomography showed a huge intrathoracic mass in the right hemithorax, which extended from the thoracic aperture to below the tracheal bifurcation, pushing the main bronchus caudally and the trachea to the left, but keeping its lumen preserved (Figure 2). Scintigraphy with I-131 confirmed the huge mass and intrathoracic expansion of the right thyroid lobe with partially preserved function (Figure 3(a) and (b)). To prevent lifelong thyrostatic therapy and future development of tracheal or other mediastinal structure compression, a prophylactic total thyroidectomy was performed through a right thoracotomy and cervicotomy. The resected intrathoracic mass measured 16 11 10 cm and weighed 710 g. The histological findings were compatible with a multinodular goiter without malignancy.