title: In vivo dosimetry of high-dose-rate interstitial brachytherapy in the pelvic region: use of a radiophotoluminescence glass dosimeter for measurement of 1004 points in 66 patients with pelvic malignancy.
abstract: OBJECTIVE
  To perform the largest in vivo dosimetry study for interstitial brachytherapy yet to be undertaken using a new radiophotoluminescence glass dosimeter (RPLGD) in patients with pelvic malignancy and to study the limits of contemporary planning software based on the results.
  
  
  METHODS
  Sixty-six patients with pelvic malignancy were treated with high-dose-rate interstitial brachytherapy, including prostate (n = 26), gynecological (n = 35), and miscellaneous (n = 5). Doses for a total of 1004 points were measured by RPLGDs and calculated with planning software in the following locations: rectum (n = 549), urethra (n = 415), vagina (n = 25), and perineum (n = 15). Compatibility (measured dose/calculated dose) was analyzed according to dosimeter location.
  
  
  RESULTS
  The compatibility for all dosimeters was 0.98 +/- 0.23, stratified by location: rectum, 0.99 +/- 0.20; urethra, 0.96 +/- 0.26; vagina, 0.91 +/- 0.08; and perineum, 1.25 +/- 0.32.
  
  
  CONCLUSIONS
  Deviations between measured and calculated doses for the rectum and urethra were greater than 20%, which is attributable to the independent movements of these organs and the applicators. Missing corrections for inhomogeneity are responsible for the 9% negative shift near the vaginal cylinder (specific gravity = 1.24), whereas neglect of transit dose contributes to the 25% positive shift in the perineal dose. Dose deviation of >20% for nontarget organs should be taken into account in the planning process. Further development of planning software and a real-time dosimetry system are necessary to use the current findings and to achieve adaptive dose delivery.
authors.affiliation: Department of Radiation Oncology, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan. takayuki.nose@jfcr.or.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nose
authors.forename: Masahiko
authors.initials: M
authors.lastname: Koizumi
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshida
authors.forename: Kinji
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Junichi
authors.initials: J
authors.lastname: Sasaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Takuyo
authors.initials: T
authors.lastname: Kozuka
authors.forename: Kotaro
authors.initials: K
authors.lastname: Gomi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Oguchi
authors.forename: Iori
authors.initials: I
authors.lastname: Sumida
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Akira
authors.initials: A
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005833:Genital Neoplasms, Female / Q000532:radiotherapy; D006801:Humans; D049449:Luminescence; D008297:Male; D008875:Middle Aged; D010386:Pelvic Neoplasms / Q000532:radiotherapy*; D010502:Perineum; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011834:Radiation Monitoring / Q000295:instrumentation* / Q000379:methods; D011879:Radiotherapy Dosage; D012007:Rectum; D014521:Urethra; D014621:Vagina