3D/4D printing
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Standardem léčby lokálně či regionálně pokročilého karcinomu hrdla dělohy je definitivní chemoradioterapie, která kombinuje systémovou chemoterapii platinou se zevní radioterapií, kterou následuje intrakavitární, tzv. uterovaginální brachyterapie. Současným standardem brachyterapie karcinomu hrdla dělohy je MR navigovaná 4D-adaptivní brachyterapie. Díky MR navigaci je při každé frakci brachyterapie jasně patrný aktuální rozsah reziduálního nádorového postižení a pokrytí cílových objemů intrakavitární aplikací do dělohy. U více než třetiny pacientek však nejde cílové struktury pokrýt terapeutickou dávkou záření vzhledem k rozsahu onemocnění, aniž by bylo možné současně dodržet bezpečné dávkové limity na okolní zdravé tkáně. Ideálním řešením takové situace je využití možnosti intersticiální aplikace jehel do míst nepokrytých samotnou intrakavitární aplikací. Standardně dodávané aplikátory pro uterovaginální brachyterapii již intersticiální aplikaci obvykle umožňují, případně lze pro aplikaci intersticiálních jehel využít 3D tiskem vyrobené či upravené aplikátory. Cílem tohoto článku je ukázat praktický postup aplikace intersticiální brachyterapie v léčbě karcinomu hrdla dělohy ve Fakultní nemocnici v Hradci Králové.
The standard treatment for locally or regionally advanced cervical cancer is definitive chemoradiotherapy, which combines systemic cisplatin chemotherapy with external-beam radiotherapy followed by intracavitary, so-called uterovaginal brachytherapy. The current standard of brachytherapy for cervical cancer is MR-guided 4D-adaptive brachytherapy. Thanks to MR navigation, the current extent of residual tumor involvement and the coverage of target volumes by intracavitary application into the uterus is visible during each brachytherapy fraction. In more than a third of patients, however, it is impossible to cover the target structures with a therapeutic dose of radiation due to the extent of the disease, without observing safe dose limits for the surrounding healthy tissues simultaneously. The ideal solution to such a situation is to use the interstitial application of needles in places not covered by the pure intracavitary application. The standard supplied applicators for uterovaginal brachytherapy usually allow interstitial application or 3D-printed or modified applicators can be used for the application of interstitial needles. This article aims to show the practical procedure of using interstitial brachytherapy in the treatment of cervical cancer at the University Hospital in Hradec Králové.
BACKGROUND: Ultra high dose rate (UHDR) radiotherapy using ridge filter is a new treatment modality known as conformal FLASH that, when optimized for dose, dose rate (DR), and linear energy transfer (LET), has the potential to reduce damage to healthy tissue without sacrificing tumor killing efficacy via the FLASH effect. PURPOSE: Clinical implementation of conformal FLASH proton therapy has been limited by quality assurance (QA) challenges, which include direct measurement of UHDR and LET. Voxel DR distributions and LET spectra at planning target margins are paramount to the DR/LET-related sparing of organs at risk. We hereby present a methodology to achieve experimental validation of these parameters. METHODS: Dose, DR, and LET were measured for a conformal FLASH treatment plan involving a 250-MeV proton beam and a 3D-printed ridge filter designed to uniformly irradiate a spherical target. We measured dose and DR simultaneously using a 4D multi-layer strip ionization chamber (MLSIC) under UHDR conditions. Additionally, we developed an "under-sample and recover (USRe)" technique for a high-resolution pixelated semiconductor detector, Timepix3, to avoid event pile-up and to correct measured LET at high-proton-flux locations without undesirable beam modifications. Confirmation of these measurements was done using a MatriXX PT detector and by Monte Carlo (MC) simulations. RESULTS: MC conformal FLASH computed doses had gamma passing rates of >95% (3 mm/3% criteria) when compared to MatriXX PT and MLSIC data. At the lateral margin, DR showed average agreement values within 0.3% of simulation at 100 Gy/s and fluctuations ∼10% at 15 Gy/s. LET spectra in the proximal, lateral, and distal margins had Bhattacharyya distances of <1.3%. CONCLUSION: Our measurements with the MLSIC and Timepix3 detectors shown that the DR distributions for UHDR scenarios and LET spectra using USRe are in agreement with simulations. These results demonstrate that the methodology presented here can be used effectively for the experimental validation and QA of FLASH treatment plans.
Repairing and regenerating damaged tissues or organs, and restoring their functioning has been the ultimate aim of medical innovations. 'Reviving healthcare' blends tissue engineering with alternative techniques such as hydrogels, which have emerged as vital tools in modern medicine. Additive manufacturing (AM) is a practical manufacturing revolution that uses building strategies like molding as a viable solution for precise hydrogel manufacturing. Recent advances in this technology have led to the successful manufacturing of hydrogels with enhanced reproducibility, accuracy, precision, and ease of fabrication. Hydrogels continue to metamorphose as the vital compatible bio-ink matrix for AM. AM hydrogels have paved the way for complex 3D/4D hydrogels that can be loaded with drugs or cells. Bio-mimicking 3D cell cultures designed via hydrogel-based AM is a groundbreaking in-vivo assessment tool in biomedical trials. This brief review focuses on preparations and applications of additively manufactured hydrogels in the biomedical spectrum, such as targeted drug delivery, 3D-cell culture, numerous regenerative strategies, biosensing, bioprinting, and cancer therapies. Prevalent AM techniques like extrusion, inkjet, digital light processing, and stereo-lithography have been explored with their setup and methodology to yield functional hydrogels. The perspectives, limitations, and the possible prospects of AM hydrogels have been critically examined in this study.
- MeSH
- 3D tisk MeSH
- bioprinting metody MeSH
- buněčné kultury MeSH
- hydrogely * chemie MeSH
- lékové transportní systémy MeSH
- lidé MeSH
- techniky 3D buněčné kultury metody MeSH
- tkáňové inženýrství * metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Klíčová slova
- 4D tisk, zobrazování čtyřrozměrné,
- MeSH
- 3D tisk MeSH
- design s pomocí počítače * MeSH
- ortodontické aparáty * trendy MeSH
- ortodontické přístroje - design * MeSH
- zobrazování trojrozměrné MeSH
- Publikační typ
- rozhovory MeSH
... Price As. 3 or 4d. No. 2. Malaria in India, by Captain S. P. James, I.M.S. Price Re. 1-8 or 2s. 3d. ... ... Price As. 3 or 4d. No. 6. ... ... Price Re. 1-8 or 2s. 3d. No. 9. ... ... Price As. 14 or is. 4d. No. 13. Oriental or Delhi Sore, by Captain S. P. James, I.M.S. ... ... Published by and on sale at the Office of the Superintendent of Government Printing, India, Calcutta. ...
73 stran ; 30 cm
- Konspekt
- Lékařské vědy. Lékařství
- NLK Obory
- vojenské lékařství
- cestovní a tropická medicína
- NLK Publikační typ
- zápisky
- vědecké zprávy