| Autor: |
Tyvin Rich, MD, Dongfeng Pan, PhD, Mahendra Chordia, PhD, Cynthia Keppel, PhD, David Beylin, MS, Pavel Stepanov, MS, Mira Jung, PhD, Dalong Pang, PhD, Scott Grindrod, PhD, Anatoly Dritschilo, MD |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
International Journal of Particle Therapy, Vol 7, Iss 4, Pp 11-18 (2021) |
| Druh dokumentu: |
article |
| ISSN: |
2331-5180 |
| DOI: |
10.14338/IJPT-D-20-00036.1 |
| Popis: |
Purpose: Proton therapy precisely delivers radiation to cancers to cause damaging strand breaks to cellular DNA, kill malignant cells, and stop tumor growth. Therapeutic protons also generate short-lived activated nuclei of carbon, oxygen, and nitrogen atoms in patients as a result of atomic transmutations that are imaged by positron emission tomography (PET). We hypothesized that the transition of 18Oto 18Fin an 18O-substituted nucleoside irradiated with therapeutic protons may result in the potential for combined diagnosis and treatment for cancer with proton therapy. Materials and Methods: Reported here is a feasibility study with a therapeutic proton beam used to irradiate H218O to a dose of 10 Gy produced by an 85 MeV pristine Bragg peak. PET imaging initiated >45 minutes later showed an 18F decay signal with T1/2 of ~111 minutes. Results: The 18Oto 18F transmutation effect on cell survival was tested by exposing SQ20B squamous carcinoma cells to physiologic 18O-thymidine concentrations of 5 μM for 48 hours followed by 1- to 9-Gy graded doses of proton radiation given 24 hours later. Survival analyses show radiation sensitization with a dose modification factor (DMF) of 1.2. Conclusions: These data support the idea of therapeutic transmutation in vitro as a biochemical consequence of proton activation of 18Oto 18F in substituted thymidine enabling proton radiation enhancement in a cancer cell. 18O-substituted molecules that incorporate into cancer targets may hold promise for improving the therapeutic window of protons and can be evaluated further for postproton therapy PET imaging. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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