Dose to the inferior pharyngeal constrictor predicts prolonged gastrostomy tube dependence with concurrent intensity-modulated radiation therapy and chemotherapy for locally-advanced head and neck cancer.
OBJECTIVE
To determine if dose and/or dose-volume parameters to anatomic swallowing structures are predictive of gastrostomy tube (PEG) dependence from chemotherapy-intensity modulated radiotherapy (IMRT) in locally advanced head and neck cancer (LAHNC).


METHODS
A retrospective study was performed on 141 consecutive patients with LAHNC (squamous cell) treated with definitive chemoIMRT with weekly concurrent carboplatin and paclitaxel. Late dysphagia was assessed by length of PEG requirement. Analysis of IMRT dose was retrospectively performed for critical swallowing structures.


RESULTS
Approximately 62% of patients required PEG, the majority placed during treatment. Mean and median time for PEG was 7.7 and 4.4 months respectively (range 1.4-43.8). Only IMRT dose to the inferior constrictor was significantly associated with length of PEG. Mean dose (of individual mean doses) was 47 Gy for prolonged PEG use versus 41 Gy for PEG ⩽ 12 months. V40 to the inferior constrictor also correlated with PEG >12 months (p = 0.02) with a mean V40 of 48% versus 41% for PEG ⩽ 12 months.


CONCLUSIONS
IMRT dose to the inferior constrictor correlated with persistent dysphagia requiring prolonged PEG use. Maintaining mean inferior constrictor dose to ⩽ 41 Gy and V40 to ⩽ 41% may help minimize gastrostomy tube dependence.
Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, USA.
Gregory
G
Vlacich
Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, USA.
Daniel E
DE
Spratt
Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, USA.
Roberto
R
Diaz
Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, USA.
John G
JG
Phillips
Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, USA.
Jostin
J
Crass
Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, USA.
Chung-I
CI
Li
Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, USA.
Yu
Y
Shyr
Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, USA. Electronic address: anthony.cmelak@vanderbilt.edu.
Anthony J
AJ
Cmelak
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D005260:Female; D005774:Gastrostomy; D006258:Head and Neck Neoplasms / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010614:Pharynx / Q000528:radiation effects*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies
Dysphagia; Head and neck; IMRT; PEG dependence; Squamous cell carcinoma