title: Reduced hypothalamic blood flow after radiation treatment of nasopharyngeal cancer: SPECT studies in 34 patients.
abstract: To determine the effect of cranial irradiation on hypothalamic blood flow, we performed 44 regional cerebral blood flow studies with 99mTc hexamethyl propyleneamine oxime (HMPAO) single-photon emission CT (SPECT) on four normal volunteers and 34 patients with pathologically proved nasopharyngeal cancer. Twenty-three men and 15 women, 30-65 years old, were divided into four study groups: group 1 served as a control and consisted of four normal volunteers and six patients studied prior to cranial irradiation; group 2 patients had cranial irradiation half a year before the SPECT study (n = 12, one from group 1); group 3 patients were irradiated 1 year before the study (n = 13, three from group 1 and two from group 2); and group 4 patients were irradiated at least 5 years before SPECT imaging (n = 9). Six patients were studied twice. Quantification of the 99mTc-HMPAO brain SPECT studies was done separately by three radiologists to obtain the hypothalamus/occipital (H/O) and hypothalamus/parasagittal (H/P) ratios. Endocrinologic studies were performed in all cases and the hypothalamus-thyrotroph-thyroid, hypothalamus-gonadotroph-testis (ovary), hypothalamus-lactotroph, hypothalamus-somatotroph, and hypothalamus-corticotroph-adrenal axes were evaluated separately. We determined that regional hypothalamic blood flow was reduced after cranial irradiation in patients with nasopharyngeal cancer. The H/O ratio of groups 3 and 4 did not differ from that of group 2 (one-half year after cranial irradiation). The H/O ratio was significantly reduced 6 months and 1 year after cranial irradiation; mean +/- SD = 0.5801 +/- 0.0829 (p less than .025), 0.5725 +/- 0.0791 (p less than .01) versus 0.6477 +/- 0.0458 before cranial irradiation, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Radiology, National Taiwan University, Medical College and Hospital, Taipei, Republic of China.
authors.forename: P U
authors.initials: PU
authors.lastname: Chieng
authors.forename: T S
authors.initials: TS
authors.lastname: Huang
authors.forename: C C
authors.initials: CC
authors.lastname: Chang
authors.forename: P N
authors.initials: PN
authors.lastname: Chong
authors.forename: R D
authors.initials: RD
authors.lastname: Tien
authors.forename: C T
authors.initials: CT
authors.lastname: Su
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging; D004702:Endocrine Glands / Q000503:physiopathology / Q000528:radiation effects; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000098:blood supply* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D009778:Occipital Lobe / Q000098:blood supply; D015609:Organotechnetium Compounds; D010091:Oximes; D011832:Radiation Injuries; D012039:Regional Blood Flow / Q000528:radiation effects; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime