Xerostomia after radiotherapy. What matters--mean total dose or dose to each parotid gland?
OBJECTIVE
Xerostomia is a debilitating side effect of radiotherapy in patients with head and neck cancer. We undertook a prospective study of the effect on xerostomia and outcomes of sparing one or both parotid glands during radiotherapy for patients with squamous cell carcinoma of the head and neck.


METHODS
Patients with locally advanced squamous cell carcinoma of the head and neck received definitive (70 Gy in 2 Gy fractions) or adjuvant (60-66 Gy in 2 Gy fractions) curative-intent radiotherapy using helical tomotherapy with concurrent chemotherapy if appropriate. Group A received < 26 Gy to the left and right parotids and group B received < 26 Gy to either parotid.


RESULTS
The study included 126 patients; 114 (55 in group A and 59 in group B) had follow-up data. There were no statistically significant differences between groups in disease stage. Xerostomia was significantly reduced in group A vs. group B (p = 0.0381). Patients in group A also had significantly less dysphagia. Relapse-free and overall survival were not compromised in group A: 2-year relapse-free survival was 86% vs. 72% in group B (p = 0.361); 2-year overall survival was 88% and 76%, respectively (p = 0.251).


CONCLUSIONS
This analysis suggests that reducing radiotherapy doses to both parotid glands to < 26 Gy can reduce xerostomia and dysphagia significantly without compromising survival. Sparing both parotids while maintaining target volume coverage and clinical outcome should be the treatment goal and reporting radiotherapy doses delivered to the individual parotids should be standard practice.
Department of Radiation Oncology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. tribius@uke.uni-hamburg.de
S
S
Tribius
J
J
Sommer
C
C
Prosch
A
A
Bajrovic
A
A
Muenscher
M
M
Blessmann
A
A
Kruell
C
C
Petersen
M
M
Todorovic
P
P
Tennstedt
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D059186:Chemoradiotherapy, Adjuvant; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010039:Otorhinolaryngologic Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D010306:Parotid Gland / Q000528:radiation effects*; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D016019:Survival Analysis; D014987:Xerostomia / Q000209:etiology*