title: Changes in salivary gland function after radiotherapy of head and neck tumors measured by quantitative pertechnetate scintigraphy: comparison of intensity-modulated radiotherapy and conventional radiation therapy with and without Amifostine.
abstract: OBJECTIVE
  The aim of this study was to compare changes in salivary gland function after intensity-modulated radiotherapy (IMRT) and conventional radiotherapy (RT), with or without Amifostine, for tumors of the head-and-neck region using quantitative salivary gland scintigraphy (QSGS).
  
  
  METHODS
  A total of 75 patients received pre- and post-therapeutic QSGS to quantify the salivary gland function. In all, 251 salivary glands were independently evaluated. Changes in the maximum uptake (DeltaU) and relative excretion rate (DeltaF) both pre- and post-RT were determined to characterize radiation-induced changes in the salivary gland function. In addition, dose-response curves were calculated.
  
  
  RESULTS
  In all groups, maximum uptake and relative excretion rate were reduced after RT (DeltaU <or=0 and DeltaF <or=0). The reduction was significantly lower for IMRT than for conventional RT. For the parotid glands, the reduction was smaller for the IMRT-low than for the IMRT-high group. For the Amifostine-high and the conventional group the difference was significant only for one parameter (DeltaU, parotid and submandibular glands, p < 0.05). In contrast to this, the difference between the Amifostine-low and the conventional group was always significant or at least showed a clear trend for both changes in U and F. In regard to the endpoint "reduction of the salivary gland excretion rate of more than 50%," the dose-response curves yielded D50-values of 34.2 +/- 12.2 Gy for the conventionally treated group and 36.8 +/- 2.9 Gy for the IMRT group. For the Amifostine group, an increased D50-values of 46.3 +/- 2.3 Gy was obtained.
  
  
  CONCLUSIONS
  Intensity-modulated RT can significantly reduce the loss of parotid gland function when respecting a certain dose threshold. Conventional RT plus Amifostine prevents reduced salivary gland function only in the patient group treated with <40.6 Gy.
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany. m.muenter@dkfz.de
authors.forename: Marc W
authors.initials: MW
authors.lastname: Münter
authors.forename: Simone
authors.initials: S
authors.lastname: Hoffner
authors.forename: Holger
authors.initials: H
authors.lastname: Hof
authors.forename: Klaus K
authors.initials: KK
authors.lastname: Herfarth
authors.forename: Uwe
authors.initials: U
authors.lastname: Haberkorn
authors.forename: Volker
authors.initials: V
authors.lastname: Rudat
authors.forename: Peter
authors.initials: P
authors.lastname: Huber
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.forename: Christian P
authors.initials: CP
authors.lastname: Karger
mesh_terms: D000328:Adult; D000368:Aged; D004999:Amifostine / Q000627:therapeutic use; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000528:radiation effects; D011837:Radiation-Protective Agents / Q000627:therapeutic use; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012469:Salivary Glands / Q000000981:diagnostic imaging / Q000528:radiation effects*; D012472:Salivation / Q000528:radiation effects; D013670:Sodium Pertechnetate Tc 99m; D014987:Xerostomia / Q000000981:diagnostic imaging / Q000209:etiology
chemical_list: D011837:Radiation-Protective Agents; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m; D004999:Amifostine