BACKGROUND: The effect of ionizing radiation on the immune system during the treatment of malignant tumors has long remained a point of great interest. This issue is currently gaining importance, especially in connection with the advancing development and availability of immunotherapeutic treatment. During cancer treatment, radiotherapy has the ability to influence the immunogenicity of the tumor by increasing the expression of certain tumor-specific antigens. These antigens can be processed by the immune system, stimulating the transformation of naïve lymphocytes into tumor-specific lymphocytes. However, at the same time, the lymphocyte population is extremely sensitive to even low doses of ionizing radiation, and radiotherapy often induces severe lymphopenia. Severe lymphopenia is a negative prognostic factor for numerous cancer dia-gnoses and negatively impacts the effectiveness of immunotherapeutic treatment. AIM: In this article, we summarize the possible influence of radiotherapy on the immune system, with a particular emphasis on the impact of radiation on circulating immune cells and the subsequent consequences of this influence on the development of cancer. CONCLUSION: Lymphopenia is an important factor influencing the results of oncological treatment, with a com-mon occurrence during radiotherapy. Strategies to reduce the risk of lymphopenia consist of accelerating treatment regimens, reducing target volumes, shortening the beam-on time of irradiators, optimizing radiotherapy for new critical organs, using particle radiotherapy, and other procedures that reduce the integral dose of radiation.
- Klíčová slova
- Lymphocytes, antitumor immune response, particle radiotherapy, radiation-induced lymphopenia, radiosensitivity, stereotactic radiotherapy,
- MeSH
- ionizující záření MeSH
- lékařská onkologie MeSH
- lidé MeSH
- lymfopenie * MeSH
- radiační onkologie * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this study was to investigate the absorbed dose and the linear energy transfer (LET) of a scanning proton pencil beam at the Proton Therapy Center Czech, applied to phantoms containing metal implants. We investigated two different phantoms composed of commonly used metals with a known chemical composition. Two rectangular phantoms consisted of water-equivalent environment material with a 65 mm thickness surrounding the 2, 5, 10 and 15 mm inserts of grade-2 and grade-5 Titanium. Track-etched detectors (TEDs) were placed behind the phantoms to gather the data. The measured LET spectra behind the implants were compared with Monte Carlo simulations using the Geant4 toolkit, version 10.03.p01. The simulations were used to provide additional information regarding the contribution of each type of particles to the LET spectra (protons, alpha particles, deuteron, neutrons, photons, and electrons) and to estimate the LET spectra above the TED's detection threshold. We used two different beam energies to study the most pertinent irradiation scenarios, one in the Bragg curve plateau and one at the maximum. The measurement of the LET spectra behind phantoms irradiated with a proton beam in the plateau region of the Bragg curve led to the detection of numerous particles with a very high LET. Lateral dose enhancement at the border between implants and the plastic material was detected when the phantoms were exposed to a proton beam and the data were recorded in the Bragg peak maximum. In this area, the dose increased 13 times for grade-2 Ti and 12 times for grade-5 Ti. The performed experimental study highlights the effect of dental implants on the LET spectra and absorbed dose when a proton pencil beam is crossing high-density titanium.
- MeSH
- artefakty MeSH
- fantomy radiodiagnostické MeSH
- lidé MeSH
- lineární přenos energie MeSH
- metoda Monte Carlo MeSH
- protonová terapie * MeSH
- radiometrie MeSH
- titan * MeSH
- zubní implantáty * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- titan * MeSH
- zubní implantáty * MeSH
Measurements described in this article were carried out with the aim of evaluating risks of the patient exposure to secondary neutrons during treatment at the Proton Therapy Centre Prague. The neutron spectral fluence was measured by means of the extended Bonner sphere spectrometer (EBS). The article presents secondary neutron spectral fluences obtained by the EBS with passive thermoluminescent detectors, i.e. pairs of 6LiF and 7LiF chips. Measurements were performed in two positions: the first one behind the Nylon 6 phantom, and the second one close to the range shifter to evaluate their contribution to the generation of neutrons. Both the Nylon 6 phantom and the range shifter were irradiated with a pencil beam of protons 4 mm in diameter and the energy of 200 MeV. The results are supplemented with the values of effective dose derived from neutron spectral fluences.
Track-etched detectors (TED) have been used as linear energy transfer (LET) spectrometers in heavy ion beams for many years. LET spectra and depth-dose distribution of a carbon ion beam were measured behind polymethylmethacrylate degraders at Heavy Ion Medical Accelerator in Chiba, Japan. The measurements were performed along monoenergetic beam with energy 290 MeV u(-1) in different positions: (1) at beam extraction area, (2) at beginning, (3) maximum and (4) behind the Bragg peak region (0, 117, 147 and 151 mm of water-equivalent depth, respectively). The LET spectra inside and outside of the primary ion beam have been evaluated. TED record only heavy charged particles with LET above 8-10 keV µm(-1), while electrons and ions with lower LET are not detected. The Geant4 simulation toolkit version 4.9.6.P01 has been used to estimate the contribution of non-detected particles to absorbed dose. Presented results demonstrate the applicability of TED for microdosimetry measurements in therapeutic carbon ion beams.
- MeSH
- částice - urychlovače přístrojové vybavení MeSH
- dávka záření MeSH
- design vybavení MeSH
- elektrony MeSH
- kalibrace MeSH
- lineární přenos energie účinky záření MeSH
- mikrotechnologie metody MeSH
- počítačová simulace MeSH
- polymethylmethakrylát chemie MeSH
- radiometrie přístrojové vybavení MeSH
- těžké ionty * MeSH
- uhlík * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- polymethylmethakrylát MeSH
- uhlík * MeSH
Dose delivered outside the proton field during radiotherapy can potentially lead to secondary cancer development. Measurements with a 170-MeV proton beam were performed with passive detectors (track etched detectors and thermoluminescence dosemeters) in three different depths along the Bragg curve. The measurement showed an uneven decrease of the dose outside of the beam field with local enhancements. The major contribution to the delivered dose is due to high-energy protons with linear energy transfer (LET) up to 10 keV µm(-1). However, both measurement and preliminary Monte Carlo calculation also confirmed the presence of particles with higher LET.
- MeSH
- celková dávka radioterapie * MeSH
- design vybavení MeSH
- fantomy radiodiagnostické MeSH
- lidé MeSH
- lineární přenos energie MeSH
- metoda Monte Carlo MeSH
- neutrony MeSH
- plánování radioterapie pomocí počítače MeSH
- polymethylmethakrylát chemie MeSH
- protonová terapie škodlivé účinky MeSH
- protony * MeSH
- radiometrie přístrojové vybavení metody MeSH
- radioterapie škodlivé účinky MeSH
- reprodukovatelnost výsledků MeSH
- termoluminiscenční dozimetrie přístrojové vybavení metody MeSH
- vysokoenergetická radioterapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Rusko MeSH
- Názvy látek
- polymethylmethakrylát MeSH
- protony * MeSH
PURPOSE: The aim of this work was to prospectively analyze the outcome of combined hormonal treatment and radical radiotherapy in high risk non metastatic prostate cancer patients (T1=4, N0-1, M0). METHODS: Between April 2003 and December 2007 196 patients with high risk prostate cancer were treated with curative intent. The treatment consisted of 2-month neoadjuvant hormonal treatment (LHRH analog), radical radiotherapy (68-78 Gy, conformal technique) and an optional 2-year adjuvant hormonal treatment. RESULTS: The median follow up time was 59 months. Fiveyear overall survival was 86% and 5-year biochemical disease free survival (DFS) 70%. Factors found to be statistically significant relative to outcomes were Gleason score (p=0.017), initial PSA value (p=0.039) and adjuvant hormonal treatment (p=0.035). There was no significant association between radiotherapy dose or volume and biochemical DFS (bDFS). Late genitourinary and gastrointestinal toxicity was acceptable. CONCLUSION: Treatment combining hormonal therapy and radical radiotherapy can be recommended for this subgroup of prostate cancer patients. Adjuvant hormonal treatment should also be used.
- MeSH
- adenokarcinom mortalita patologie terapie MeSH
- antitumorózní látky hormonální terapeutické užití MeSH
- celková dávka radioterapie MeSH
- chemoradioterapie * MeSH
- dospělí MeSH
- konformní radioterapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- míra přežití MeSH
- nádory prostaty mortalita patologie terapie MeSH
- následné studie MeSH
- neoadjuvantní terapie MeSH
- prognóza MeSH
- prospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- staging nádorů MeSH
- stupeň nádoru MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antitumorózní látky hormonální MeSH
BACKGROUND: Low-grade gliomas WHO II (LGG) are mostly detected in patients with neurological symptomatology between 20 and 45 years of age very often as secondary epilepsy. We present two cases in which low-grade gliomas attacked neurological zones. Neurosurgical resection was subtotal because of the risk of the damage in neurocognitive functions in both these patients. After the operation, both patients were followed at neurosurgery department in regular intervals using different imaging methods (MRI, MRS and PET). After resections, the MRI detected the enlargement of the volumes of the tumor residua in both patients. PATIENTS AND METHODS: Owing to the risk of up-grading to high-grades glial tumors (overexpression of EGFR and VEGF), both patients were indicated for curative treatment by external beam radiotherapy combined with chemotherapy (Temodal®) and adjuvant chemotherapy. RESULTS: After the end of this treatment, the MRI proved considerable partial regressions in both patients. Moreover, three months later, the MRI did not prove any residual disease. CONCLUSION: Radiotherapy combined with the administration of Temodal should prolong the OS and TTP in patients with a high risk of up-grading of low-grade gliomas of the brain. Both the patients are in a follow-up program, also because of the risk of duplicite brain tumor.
- MeSH
- chemoradioterapie * MeSH
- dospělí MeSH
- gliom diagnóza chirurgie terapie MeSH
- kombinovaná terapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- supratentoriální nádory diagnóza chirurgie terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- kazuistiky MeSH
The authors describe an unusual case of a young adult patient with symptomatic tricuspid valve insufficiency as a late consequence of pulmonary valve balloon dilatation in childhood. Patient was successfully treated by tricuspid valve repair with neo-chordae implantation and a ring plasty. Two years after the operation the patient, an active sportsman, is asymptomatic with trace tricuspid regurgitation on the echo examination.
- MeSH
- dospělí MeSH
- katetrizace škodlivé účinky MeSH
- lidé MeSH
- mladý dospělý MeSH
- plicní chlopeň * MeSH
- stenóza pulmonální chlopně terapie MeSH
- trikuspidální insuficience etiologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
Spectral fluence of photoneutrons generated in the head of the radiotherapeutic linac Varian 2100 C/D was measured by means of the Bonner spheres spectrometer whose active detector of thermal neutrons was replaced by a track detector, i.e. a sandwich of four CR-39s with the boron radiator inserted between them. Measurements with different collimator settings showed that the fluence of photoneutrons was higher for the more open collimator.
- MeSH
- algoritmy MeSH
- částice - urychlovače * MeSH
- lidé MeSH
- neutrony * MeSH
- radiometrie přístrojové vybavení metody MeSH
- rentgenové záření * MeSH
- spektrofotometrie * MeSH
- vysokoenergetická radioterapie přístrojové vybavení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Mycotic aneurysm of the coronary artery occurs in less than 1% of patients with infective endocarditis and only few cases of successful treatment has been described in the literature. The paper presents a case of 64 years old man with infective endocarditis of the mitral valve, complicated with a development of mycotic aneurysm of the right coronary artery, who was successfully surgically treated.
- MeSH
- bakteriální endokarditida komplikace mikrobiologie MeSH
- koronární aneurysma diagnóza mikrobiologie chirurgie MeSH
- lidé středního věku MeSH
- lidé MeSH
- stafylokokové infekce diagnóza MeSH
- zánětlivé aneurysma diagnóza mikrobiologie chirurgie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- kazuistiky MeSH
