Oxygen-Guided Radiation Therapy.
Int J Radiat Oncol Biol Phys
; 103(4): 977-984, 2019 03 15.
Article
em En
| MEDLINE
| ID: mdl-30414912
ABSTRACT
PURPOSE:
It has been known for over 100 years that tumor hypoxia, a near-universal characteristic of solid tumors, decreases the curative effectiveness of radiation therapy. However, to date, there are no reports that demonstrate an improvement in radiation effectiveness in a mammalian tumor on the basis of tumor hypoxia localization and local hypoxia treatment. METHODS AND MATERIALS For radiation targeting of hypoxic subregions in mouse fibrosarcoma, we used oxygen images obtained using pulse electron paramagnetic resonance pO2 imaging combined with 3D-printed radiation blocks. This achieved conformal radiation delivery to all hypoxic areas in FSa fibrosarcomas in mice.RESULTS:
We demonstrate that treatment delivering a radiation boost to hypoxic volumes has a significant (P = .04) doubling of tumor control relative to boosts to well-oxygenated volumes. Additional dose to well-oxygenated tumor regions minimally increases tumor control beyond the 15% control dose to the entire tumor. If we can identify portions of the tumor that are more resistant to radiation, it might be possible to reduce the dose to more sensitive tumor volumes without significant compromise in tumor control.CONCLUSIONS:
This work demonstrates in a single, intact mammalian tumor type that tumor hypoxia is a local tumor phenomenon whose treatment can be enhanced by local radiation. Despite enormous clinical effort to overcome hypoxic radiation resistance, to our knowledge this is the first such demonstration, even in preclinical models, of targeting additional radiation to hypoxic tumor to improve the therapeutic ratio.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
/
Radioterapia Guiada por Imagem
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Int J Radiat Oncol Biol Phys
Ano de publicação:
2019
Tipo de documento:
Article