The effect of amifostine or IMRT to preserve the parotid function after radiotherapy of the head and neck region measured by quantitative salivary gland scintigraphy.
OBJECTIVE
In this retrospective study, two approaches to preserve the parotid function after radiotherapy (RT) were compared: application of the radioprotective agent amifostine during RT and parotid-sparing intensity-modulated radiotherapy (IMRT).


METHODS
Patients were qualified for this analysis if (1) both parotid glands received a radiation dose of >or=50Gy using conventional radiotherapy techniques (cRT) or if they received a parotid-sparing IMRT as alternative, if (2) salivary gland scintigraphies before and after RT were performed, and if (3) a normal parotid function was present before RT. Quantitative salivary gland scintigraphy was used to assess the parotid gland function.


RESULTS
Altogether 275 salivary gland scintigraphies of 100 patients were analyzed. The mean relative tracer uptake (DeltaU) of patients treated with cRT, cRT with amifostine and IMRT 1-12 months after RT was 0.59 (95%CI 0.54-0.65), 0.67 (95%CI 0.59-0.76), and 0.93 (95%CI 0.78-1.07), respectively. The mean relative DeltaU 13-47 months after RT was 0.40 (95%CI 0.32-0.49), 0.60 (95%CI 0.48-0.71), and 0.92 (95%CI 0.56-1.28). At 1-12 months after RT, ANOVA testing with post-hoc comparison using the Bonferroni correction showed a significant difference between IMRT and cRT (p<0.001) or IMRT and amifostine (p<0.01). The difference between amifostine and cRT was not significant during the first year. At 13-47 months after RT, the difference between cRT and amifostine was significant (p=0.02).


CONCLUSIONS
Our data suggest that both amifostine and IMRT are able to partially preserve the parotid function after radiotherapy. The effect of IMRT appeared to be much greater.
Rudat
Volker
V
Department of Radiation Oncology, University Hospital Hamburg-Eppendorf (UKE), Germany. volker.rudat@gmail.com
Münter
Mark
M
Rades
Dirk
D
Grötz
Knut A
KA
Bajrovic
Amira
A
Haberkorn
Uwe
U
Brenner
Winfried
W
Debus
Jürgen
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004999:Amifostine / Q000627:therapeutic use*; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging* / Q000528:radiation effects*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000627:therapeutic use*; D011877:Radionuclide Imaging; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D014987:Xerostomia / Q000517:prevention & control*
D011837:Radiation-Protective Agents; D004999:Amifostine