title: CT manifestation in the pararectal area following fast neutron radiotherapy.
abstract: Sixty-four pelvic CT studies of 38 patients with pelvic malignancies were obtained at various times (21 to 678 days) following fast neutron radiotherapy. Multiple scans (2 to 3) were available in 19 cases. Fractionated neutron radiotherapy was delivered over four to seven weeks to a total dose of 54 Gy to 60 Gy photon equivalent. Radiation-induced changes on CT were symmetrical thickening of the perirectal fascia (87%), widening of the presacral space (82%), and thickening of the walls of the bladder and rectum (21% and 11%, respectively). Serial CT studies showed that these changes became stable after 12 weeks from radiotherapy in 13 of 14 patients (93%). CT manifestations of radiation-induced changes in the pararectal area were rather regular and would be easy to differentiate from local recurrence or secondary disease.
authors.affiliation: Department of Radiology, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ohtomo
authors.forename: W P
authors.initials: WP
authors.lastname: Shuman
authors.forename: B R
authors.initials: BR
authors.lastname: Griffin
authors.forename: G R
authors.initials: GR
authors.lastname: Stewart
authors.forename: G E
authors.initials: GE
authors.lastname: Laramore
authors.forename: A A
authors.initials: AA
authors.lastname: Moss
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005214:Fast Neutrons / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010386:Pelvic Neoplasms / Q000532:radiotherapy*; D010388:Pelvis / Q000000981:diagnostic imaging / Q000528:radiation effects; D012007:Rectum / Q000000981:diagnostic imaging* / Q000528:radiation effects; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000528:radiation effects