title: Human neoplasm pH and response to radiation therapy: P-31 MR spectroscopy studies in situ.
abstract: Thirty-five human neoplasms from various sites and of various histologic types and stages were examined with phosphorus-31 magnetic resonance spectroscopy in situ. The tumors included 13 squamous cell carcinomas of the head and neck (lymph nodes), eight Hodgkin lymphomas, six non-Hodgkin lymphomas, four carcinomas of the breast, one melanoma, one sarcoma, one neuroblastoma, and one mucoepidermoid sarcoma of the salivary glands. Thirty-four of the neoplasms had normal to slightly alkaline pH before irradiation. During fractionated radiation therapy, the pH stayed in a range of from near neutral to alkaline and rose to 7.6-8.0 at several time points of radiation therapy for some tumors. These results suggest that most tumor cells in human neoplasms are well oxygenated and that only a negligible fraction are chronic hypoxic cells. The fluctuating alkaline pH during radiation therapy occurred regardless of the responsiveness of the treated tumors.
authors.affiliation: MR Research Center, Cleveland Clinic Foundation, OH 44106.
authors.forename: T C
authors.initials: TC
authors.lastname: Ng
authors.forename: A W
authors.initials: AW
authors.lastname: Majors
authors.forename: S
authors.initials: S
authors.lastname: Vijayakumar
authors.forename: N J
authors.initials: NJ
authors.lastname: Baldwin
authors.forename: F J
authors.initials: FJ
authors.lastname: Thomas
authors.forename: I
authors.initials: I
authors.lastname: Koumoundouros
authors.forename: M E
authors.initials: ME
authors.lastname: Taylor
authors.forename: S F
authors.initials: SF
authors.lastname: Grundfest
authors.forename: T F
authors.initials: TF
authors.lastname: Meaney
authors.forename: R R
authors.initials: RR
authors.lastname: Tubbs
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000532:radiotherapy; D004307:Dose-Response Relationship, Radiation; D006689:Hodgkin Disease / Q000175:diagnosis* / Q000532:radiotherapy; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000532:radiotherapy; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D011879:Radiotherapy Dosage