title: Oxygenated and reoxygenated tumors show better local control in radiation therapy for cervical cancer.
abstract: The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO(2)) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high-dose rate intracavitary irradiation. The pO(2) was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO(2) before radiation therapy was 17.3 +/- 10.8 mm Hg. The 3-year local control rates of patients with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO(2) was 23.6 +/- 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.
authors.affiliation: Research Center Hospital of Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.forename: T
authors.initials: T
authors.lastname: Ohno
authors.forename: S
authors.initials: S
authors.lastname: Kato
authors.forename: Y
authors.initials: Y
authors.lastname: Niibe
authors.forename: S
authors.initials: S
authors.lastname: Morita
authors.forename: H
authors.initials: H
authors.lastname: Tsujii
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001918:Brachytherapy / Q000379:methods; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D011336:Probability; D016016:Proportional Hazards Models; D011879:Radiotherapy Dosage; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*
chemical_list: D010100:Oxygen