Prospective evaluation to establish a dose response for clinical oral mucositis in patients undergoing head-and-neck conformal radiotherapy.
OBJECTIVE
We conducted a clinical study to correlate oral cavity dose with clinical mucositis, perform in vivo dosimetry, and determine the feasibility of obtaining buccal mucosal cell samples in patients undergoing head-and-neck radiation therapy. The main objective is to establish a quantitative dose response for clinical oral mucositis.


METHODS
Twelve patients undergoing radiation therapy for head-and-neck cancer were prospectively studied. Four points were chosen in separate quadrants of the oral cavity. Calculated dose distributions were generated by using AcQPlan and Eclipse treatment planning systems. MOSFET dosimeters were used to measure dose at each sampled point. Each patient underwent buccal sampling for future RNA analysis before and after the first radiation treatment at the four selected points. Clinical and functional mucositis were assessed weekly according to National Cancer Institute Common Toxicity Criteria, Version 3.


RESULTS
Maximum and average doses for sampled sites ranged from 7.4-62.3 and 3.0-54.3 Gy, respectively. A cumulative point dose of 39.1 Gy resulted in mucositis for 3 weeks or longer. Mild severity (Grade </= 1) and short duration (</=1 week) of mucositis were found at cumulative point doses less than 32 Gy. Polymerase chain reaction consistently was able to detect basal levels of two known radiation responsive genes.


CONCLUSIONS
In our sample, cumulative doses to the oral cavity of less than 32 Gy were associated with minimal acute mucositis. A dose greater than 39 Gy was associated with longer duration of mucositis. Our technique for sampling buccal mucosa yielded sufficient cells for RNA analysis using polymerase chain reaction.
Narayan
Samir
S
Department of Radiation Oncology, University of California Davis Medical Center, Sacramento, CA, USA.
Lehmann
Joerg
J
Coleman
Matthew A
MA
Vaughan
Andrew
A
Yang
Claus Chunli
CC
Enepekides
Danny
D
Farwell
Gregory
G
Purdy
James A
JA
Laredo
Grace
G
Nolan
Kerry
K
Pearson
Francesca S
FS
Vijayakumar
Srinivasan
S
D000199:Actins / Q000235:genetics; D004261:DNA Replication / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D009061:Mouth Mucosa / Q000473:pathology / Q000528:radiation effects; D018579:Patient Selection; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D044469:Racial Groups; D011877:Radionuclide Imaging; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D013280:Stomatitis / Q000000981:diagnostic imaging* / Q000453:epidemiology*
D000199:Actins; D012337:RNA, Ribosomal, 18S; D012313:RNA