During implementation of the total skin electron treatment, using six-dual-field technique, at radiotherapy department a large number of measurements are needed. To assess depth dose curve required ...by clinicians and dose uniformity over a whole treatment plane, combinations of different irradiation parameters are used (electron energy, beam angle, scatterers). Measurements for each combination must be performed. One possible way to reduce number of measurements is to model the treatment using the Monte Carlo simulation of electron transport. We made a simplified multiple-source Monte Carlo model of electron beam and tested it by comparing calculations and experimental results. Calculated data differs less than 5 percent from measurements in the treatment plane. During the treatment patient can be approximated using cylinders with different diameters and orientations. We tried to model the depth dose variations in the total skin electron treatment not just around the body cross-section (simplified to cylinders of different diameters), but also along the body to account for the variations in body curvature longitudinally. This effect comes down to the problem of modeling distribution in different cylinders, but varying the longitudinal orientation of those cylinders. We compared Monte Carlo calculations and film measurements of depth dose curves for two orientations of the cylindrical phantom, which were the simplest for experimental arrangement. Comparison of the results proved accuracy of the model and we used it to calculate depth dose curves for a number of other cylinder orientations.
It is often presumed that the main role of hormone binding to albumins and binding proteins (BPs) is to reduce oscillating levels of free hormone molecules and to transport steroid hormones.
This ...paper is an attempt to define possible consequences of hormone molecules binding to carrier proteins in circulation.
Binding to albumins and BPs prevents exact and quick control of hormone actions. Hormones without significant protein binding govern vital and fast acting regulatory mechanisms (blood glucose or calcium) in which any added inertia might be dangerous. In the presented model, the added inertia for a partially bound hormone (H) is defined as: H
bound/H
free. Values, calculated from the reported data, range from 0.4 for GH to more than 2000 for T
4. In comparison to albumins, high-affinity BPs make more stable reserve that would cover periods of low or no hormone secretion. At the same time, hormone molecules are taken away from the blood level control and thus might be considered sequestrated.
For hormones without protein binding, the well-perfused areas of the body, or the areas with increased capillary permeability, would be more exposed, making an uneven distribution among target tissues. For the hormone that binds blood proteins, places of secretion and tissue perfusion become unimportant, since the hormone is being liberated anywhere in the circulation (i.e., for strongly bound IGFs, IGF binding proteins do not just stabilize proinsulin actions of IGF-1, but also make all parts of body to be under the same exposure to liberated IGFs, an important feature to promote a symmetrical bone growth).
Estrogens are known to stimulate liver secretion of different BPs. A possible explanation is that in the follicular phase there is a small initial mass of granulosa cells, and it takes time to saturate free estrogen carriers, before the normal free hormone level can be reached and FSH secretion inhibited. Less inert peptide inhibin might suppress FSH before free estrogens reach the required level. Without inhibin suppression, an increased FSH level with an increased number of growing follicles can be expected. Estrogens increased production of BPs augments inertia of the estrogen loop and possibly modulates the FSH/estrogen negative feedback.
We report on a 62-year-old HIV-negative male patient with Kaposi sarcoma. After 8 years of treatment of smaller localized skin lesions with surgery and local radiotherapy, the patient developed ...extensive lesions of the whole skin. The extent of the lesions required the administration of the total skin electron therapy (TSET). Until then, TSET had been used at our Department only for the treatment of mycosis fungoides. The dose delivered was 30 Gy higher than in a conventional radiotherapy treatment, where doses are usually between 8 and 24 Gy. Six months after the TSET therapy, the lesions completely regressed, except for two large facial lesions, which were surgically removed. Major side effects were mild erythema and hyperpigmentation of the skin. Erythema disappeared a month after the therapy.
Maligne bolesti su jedan od vodećih uzroka smrtnosti djece u Europi i Americi. Posljednjih desetak godina učinjen je bitan napredak kako u dijagnostici tako i u njihovom liječenju, naročito u ...liječenju malignih limfoma. Uvođenjem novih metoda liječenja (nove kombinacije citostatika, zračenja, kirurškog zahvata, monoklonskih antitijela te transplantacije koštane srži) i u ovih bolesnika danas je moguće postići visok postotak dugotrajnih remisija i izlječenja.
Inverted papilloma is an epithelial neoplasm of the lateral nasal wall and adjacent sinuses characterized by a marked propensity for recurrence and a significant association with carcinoma. In this ...retrospective study we present 31 cases treated by our departments between 1982 and 1999. The aim was to compare our results to those of other authors especially regarding surgical management. The male to female ratio of these patients was 2:1 and most patients were in the 6th and 7th decades of life. Conservative surgery was used in most cases as the initial treatment. The overall recurrence rate was low and there were 3 cases associated with carcinoma. We conclude that the results of conservative surgery in selected cases are comparable to those using radical methods. A review of the literature is presented and particular attention is dedicated to the literature concerning analysis of p53 expression, HPV and Epstein-Barr infection and apoptosis in inverted papilloma.
Radioterapija ima objedinjavajuću ulogu u kurativnom liječenju raka dojke. Nakon poštednog operativnog zahvata intraduktalnog ili invazivnog karcinoma dojke, radioterapija jamačno produžuje razdoblje ...bez lokoregionalnih znakova bolesti i poboljšava izglede sačuvanja dojke. Nakon mastektomije pažljivo izabranih bolesnica, lokoregionalna radioterapija će smanjiti mogućnost recidiva i produljiti srednje preživljenje. Budući je danas timski pristup liječenju raka dojke vrlo poželjan, liječnici u timu imaju veliku odgovornost pa osim svoje struke moraju imati uvid i u struke drugih kolega, kao što su principi radioterapije, kriteriji selekcije, tehnike, rezultate i nuspojave zračenja itd. Cilj ovog rada je upoznavanje čitatelja s temeljnim znanjima o radioterapiji i radiobiologiji, te radioterapijskom liječenju raka dojke, danas najčešće zloćudne bolesti u žena. S poboljšanim tehnikama planiranja i provođenja zračenja došlo je do značajnih dostignuća u smanjenju lokalnog recidiva, preživljenju bez znakova bolesti, te, možda, i ukupnom preživljenju, bez uzrokovanja većih oštećenja na normalnom tkivu.
Aim. Analysis of the expression of genes encoding IL-1 alpha , IL-1 beta , IL-2, IL-5, IL-10, INF gamma , and TNF alpha cytokines in peripheral blood mononuclear cells (PBMC) of patients undergoing ...postmastectomy radiotherapy. Methods. Freshly isolated PBMC collected from fifteen patients before, during, and at the end of irradiation treatment were studied by a reverse transcription-polymerase chain reaction (RT-PCR). Results. IL-1 alpha , IL-2, IL-5, and INF gamma gene transcripts were rarely or never detectable, whereas IL-10 expression was often observed in the pre-treatment samples. Most importantly, TNF alpha transcripts were detected in over 45% of the patients after irradiation treatment. In 20% of the patients co-expression of both TNF alpha and IL-1 beta genes were observed. Conclusion. These data, obtained by taking advantage of a sensitive technique closely reflecting in vivo events, suggest that systemic monocyte activation could take place in therapeutically irradiated patients.
Rak dojke najčešća je maligna bolest u žena. Ranom dijagnostikom i sve uspješnijim liječenjem invazivnog raka dojke postignut je značajan pad mortaliteta, produljenje preživljenja i poboljšanje ...kvalitete života bolesnica. Postupak s neinvazivnim rakom dojke međutim povezan je s nekim dvojbama i sviješću o problemu predijagnosticiranja i pretjeranog liječenja nekih bolesnica. U tekstu koji slijedi multidisciplinarni tim stručnjaka donosi prve hrvatske smjernice čija je svrha standardizacija i optimalizacija kriterija i postupaka dijagnostike, liječenja i praćenja bolesnica s neinvazivnim rakom dojke u Republici Hrvatskoj.
Multipli primarni tumori koji se javljaju kod istog bolesnika, metakrono ili sinkrono, relativno su rijedak događaj s porastom učestalosti posljednjih desetljeća. Cilj je ovog istraživanja utvrditi ...njihovu učestalost kod bolesnika liječenih hospitalno u Zavodu za radioterapijsku onkologiju Klinike za onkologiju Medicinskog fakulteta Sveučilišta u Zagrebu, KBC Zagreb u periodu od 2003. do 2009. godine. Učestalost je multiplih malignih tumora u navedenom periodu bila 2,4%. Od ukupno 103 bolesnika 97 je imalo dva, a 6 tri primarna tumora. Metakronih je tumora bilo 88, a sinkronih 20. Učestalost im je bila veća kod žena nego kod muškaraca, a i pojavljivali su se ranije kod žena nego kod muškaraca. Najčešće su kombinacije prvog i drugoga metakronog tumora kod muškaraca bile: rak prostate-maligni tumor probavnog sustava (osobito rak rektuma i debelog crijeva) i obrnutim redoslijedom te hematološke zloćudne bolesti-maligni tumor probavnog sustava; a kod žena: rak dojke-rak kontralateralne dojke i hematološke zloćudne bolesti (osobito ne-Hodgkinov limfom)-rak dojke. Valja očekivati da će učestalost bolesnika s višestrukim primarnim tumorima rasti, i zbog programa ranog otkrivanja tumora i zbog uspješnijeg liječenja i dužeg očekivanog trajanja života.
