About 26 000 patients are treated per year with radiotherapy for non-malignant diseases in the Czech Republic. Approximately 75% of them are treated on X-ray therapy units and most of these patients undergo radiotherapy of heel spurs. The evaluation of radiation exposure of these patients was based on measured organ doses and on data from clinical practice. Collective effective doses for particular diagnoses were calculated in order to compare doses resulting from different diagnoses treated on X-ray therapy units. The collective effective dose from radiotherapy of heel spurs in the Czech Republic in 2013 was evaluated to 77 manSv. It represents 25.6% of the total collective effective dose for all diagnoses of radiotherapy for non-malignant diseases treated on X-ray therapy units.
- MeSH
- celková dávka radioterapie MeSH
- fantomy radiodiagnostické * MeSH
- kritické orgány účinky záření MeSH
- lidé MeSH
- monitorování radiace metody MeSH
- ostruha kosti patní radioterapie MeSH
- plánování radioterapie pomocí počítače metody MeSH
- radiační expozice analýza MeSH
- rentgenová terapie metody MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
In radiotherapy, radiochromic films can be used for verification of delivery of dose distributions calculated by treatment planning systems. The main objective of this work was to compare three different techniques for evaluation of dose distributions for prostate cancer treatment plans using radiochromic EBT3 films. These techniques are: red channel evaluation taking into account only a response of irradiated film (R), red channel evaluation taking into account a response of unirradiated and irradiated film (Rcor) and multichannel evaluation in FilmQA software (RGB). Also comparison between film and MatriXX measurement was performed. Comparison showed that gamma analysis passing rates strongly depend on evaluation technique and on a model of scanner for digitizing films. The highest gamma passing rates were obtained with red channel evaluation taking into account a response of unirradiated and irradiated film using Epson V750 scanner (Rcor) and multichannel evaluation in FilmQA using Epson 11000XL scanner.
- MeSH
- algoritmy MeSH
- celková dávka radioterapie MeSH
- fantomy radiodiagnostické * MeSH
- filmová dozimetrie přístrojové vybavení metody MeSH
- kalibrace MeSH
- lidé MeSH
- nádory prostaty radioterapie MeSH
- plánování radioterapie pomocí počítače metody MeSH
- radioterapie s modulovanou intenzitou metody MeSH
- záření gama MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- srovnávací studie MeSH
PURPOSE: To characterize stray radiation around the target volume in scanning proton therapy and study the performance of active neutron monitors. METHODS: Working Group 9 of the European Radiation Dosimetry Group (EURADOS WG9-Radiation protection in medicine) carried out a large measurement campaign at the Trento Centro di Protonterapia (Trento, Italy) in order to determine the neutron spectra near the patient using two extended-range Bonner sphere spectrometry (BSS) systems. In addition, the work focused on acknowledging the performance of different commercial active dosimetry systems when measuring neutron ambient dose equivalents, H(∗)(10), at several positions inside (8 positions) and outside (3 positions) the treatment room. Detectors included three TEPCs--tissue equivalent proportional counters (Hawk type from Far West Technology, Inc.) and six rem-counters (WENDI-II, LB 6411, RadEye™ NL, a regular and an extended-range NM2B). Meanwhile, the photon component of stray radiation was deduced from the low-lineal energy transfer part of TEPC spectra or measured using a Thermo Scientific™ FH-40G survey meter. Experiments involved a water tank phantom (60 × 30 × 30 cm(3)) representing the patient that was uniformly irradiated using a 3 mm spot diameter proton pencil beam with 10 cm modulation width, 19.95 cm distal beam range, and 10 × 10 cm(2) field size. RESULTS: Neutron spectrometry around the target volume showed two main components at the thermal and fast energy ranges. The study also revealed the large dependence of the energy distribution of neutrons, and consequently of out-of-field doses, on the primary beam direction (directional emission of intranuclear cascade neutrons) and energy (spectral composition of secondary neutrons). In addition, neutron mapping within the facility was conducted and showed the highest H(∗)(10) value of ∼ 51 μSv Gy(-1); this was measured at 1.15 m along the beam axis. H(∗)(10) values significantly decreased with distance and angular position with respect to beam axis falling below 2 nSv Gy(-1) at the entrance of the maze, at the door outside the room and below detection limit in the gantry control room, and at an adjacent room (<0.1 nSv Gy(-1)). Finally, the agreement on H(∗)(10) values between all detectors showed a direct dependence on neutron spectra at the measurement position. While conventional rem-counters (LB 6411, RadEye™ NL, NM2-458) underestimated the H(∗)(10) by up to a factor of 4, Hawk TEPCs and the WENDI-II range-extended detector were found to have good performance (within 20%) even at the highest neutron fluence and energy range. Meanwhile, secondary photon dose equivalents were found to be up to five times lower than neutrons; remaining nonetheless of concern to the patient. CONCLUSIONS: Extended-range BSS, TEPCs, and the WENDI-II enable accurate measurements of stray neutrons while other rem-counters are not appropriate considering the high-energy range of neutrons involved in proton therapy.
- MeSH
- dávka záření MeSH
- fantomy radiodiagnostické MeSH
- fotony MeSH
- neutrony MeSH
- protonová terapie přístrojové vybavení metody MeSH
- protony MeSH
- radiometrie přístrojové vybavení metody MeSH
- spektrální analýza přístrojové vybavení metody MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
The purpose of this work was an evaluation of organ doses and effective doses from three verification techniques in Image-Guided Radiotherapy: from kilovoltage (kV) cone beam computed tomography (CBCT) scans, from two orthogonal kV images and from two orthogonal megavoltage (MV) images for two different treatment sites: pelvis and head and neck (H&N). For comparison reasons, organ doses and effective doses from prostate and H&N radiotherapy were also evaluated. Measurements of organ doses were performed in a male anthropomorphic Rando phantom by means of thermoluminescent dosemeters. In this investigation, measured organ doses from one CBCT scan, from two MV images and from two kV images of pelvis represent typically 1-6, 1-10 and 0.05-1 %, respectively, of organ doses resulting from one fraction of prostate radiotherapy. The maximum effective doses from CBCT scans, kV images and MV images of pelvis are 5.6, 0.8 and 11.9 mSv, respectively.
- MeSH
- celková dávka radioterapie MeSH
- fantomy radiodiagnostické MeSH
- hlava radiografie MeSH
- krk radiografie MeSH
- lidé MeSH
- nádory prostaty radiografie radioterapie MeSH
- pánev radiografie MeSH
- počítačová tomografie s kuželovým svazkem MeSH
- radioterapie řízená obrazem MeSH
- termoluminiscenční dozimetrie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cílem studie bylo zavedení detekce bodové mutace na 12. kodonu prvního exonu Ki-ras genu u nemocných s adenokarcinomem pankreatu použitím tří modifikací polymerázové řetězové reakce a následným restrikčním štěpením (PCR-RFLP) naamplifikovaných produktů. K detekci byly využity tři dvojice primerů generujících artefaciální místo pro restrikční enzymy s pouze jednou alelickou formou. Použitím dvoustupňové PCR-RFLP a dvou modifikací jednostupňové PCRRFLP bylo vyšetřeno 12 DNA vyizolovaných ze solidních tumorů (5), pankreatických sekretů (6) a z lymfocytů periferní krve (1) u pacienta s generalizováným stadiem onemocnění. Studie podává srovnání použitých metod k detekci mutace na Ki-ras genu a kloní se k závěru, že dvoustupňová PCR-RFLP analýza vzhledem ke své citlivosti je vhodnou metodou pro detekci bodových mutací bez použití oligonukleotidových hybridizací a sekvenace DNA.
Present study was undertaken to detect Ki-ras point mutation at codon 12 in pancreatic adenocarcinomas (CaP) using the polymerase chain reaction-restriction fi"agment lengths polymorphism (PCR-RFLP). Three modifications of PCR-RFLP were performed with a mismatched primers creating a recognition site with only one allelic form (wild or mutated). Using two-step PCR-RFLP and two modifications of one-step PCR-RFLP we examined 5 resected adenocarcinomas of pancreas, 6 pancreatic juices and one DNA sample from peripheral blood of patient with generalized stadium of CaP. We compare all techniques and conclude, that the very sensitive two step PCR-RFLP is a suitable method for detection point mutations and eliminates the need for either oligonucleotide hybridization or DNA sequencing.
- MeSH
- lidé MeSH
- nádory jater diagnóza MeSH
- nádory žlučových cest diagnóza MeSH
- Check Tag
- lidé MeSH
- MeSH
- lidé MeSH
- nádory žlučových cest MeSH
- terapie ultrafialovými paprsky MeSH
- Check Tag
- lidé MeSH
- MeSH
- bodová mutace genetika MeSH
- dospělí MeSH
- genetické markery MeSH
- lidé MeSH
- nádory slinivky břišní diagnóza MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
