Hypoxia Imaging and Adaptive Radiotherapy: A State-of-the-Art Approach in the Management of Glioma

Frontiers in Medicine

article

Michael Gérard¹  Jean-Sébastien Guillamo¹  Bernard Dubray⁴  Myriam Bernaudin¹  Juliette Thariat²  Samuel Valable¹  Aurélien Corroyer-Dulmont¹  Paul Lesueur¹  Solène Collet¹  Michel Chérel⁶  Mickael Bourgeois⁶  Dinu Stefan²  Elaine Johanna Limkin⁷  Cécile Perrio⁸ 

[1] Normandie Université, ISTCT/CERVOxy Group;Department of Radiation Oncology, Centre Lutte Contre le Cancer François Baclesse;Department of Neurology, Centre Hospitalier Universitaire de Nîmes;Département de Radiothérapie et de Physique Médicale, Laboratoire QuantIF–LITIS [EA 4108], Centre de Lutte Contre le Cancer Henri Becquerel, Université de Normandie;Department of Radiophysics, Centre Lutte Contre le Cancer François Baclesse;INSERM U1232 Centre de Recherche en Cancérologie et Immunologie Nantes Angers (CRCINA);Department of Radiotherapy, Université Paris-Saclay;Normandie Université, ISTCT/LDM-TEP Group

关键词: glioblastoma;    hypoxia;    imaging;    PET;    MRI;    radiation therapy;   

DOI  :  10.3389/fmed.2019.00117

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

Severe hypoxia [oxygen partial pressure (pO 2 ) below 5–10 mmHg] is more frequent in glioblastoma multiforme (GBM) compared to lower-grade gliomas. Seminal studies in the 1950s demonstrated that hypoxia was associated with increased resistance to low–linear energy transfer (LET) ionizing radiation. In experimental conditions, the total radiation dose has to be multiplied by a factor of 3 to achieve the same cell lethality in anoxic situations. The presence of hypoxia in human tumors is assumed to contribute to treatment failures after radiotherapy (RT) in cancer patients. Therefore, a logical way to overcome hypoxia-induced radioresistance would be to deliver substantially higher doses of RT in hypoxic volumes delineated on pre-treatment imaging as biological target volumes (BTVs). Such an approach faces various fundamental, technical, and clinical challenges. The present review addresses several technical points related to the delineation of hypoxic zones, which include: spatial accuracy, quantitative vs. relative threshold, variations of hypoxia levels during RT, and availability of hypoxia tracers. The feasibility of hypoxia imaging as an assessment tool for early tumor response to RT and for predicting long-term outcomes is discussed. Hypoxia imaging for RT dose painting is likewise examined. As for the radiation oncologist's point of view, hypoxia maps should be converted into dose-distribution objectives for RT planning. Taking into account the physics and the radiobiology of various irradiation beams, preliminary in silico studies are required to investigate the feasibility of dose escalation in terms of normal tissue tolerance before clinical trials are undertaken.

【 授权许可】

CC BY