Sanguineti et al reported predictors of PEG tube dependency in a patient with oropharyngeal cancer after intensity modulated radiotherapy (IMRT).
The authors are from the University of Texas Medical Branch in Galveston, Johns Hopkins University, and San Raffaele Scientific Institute in Milan.
Patient selection: oropharyngeal cancer status post intensity modulated radiotherapy (IMRT)
Outcome: percutaneous endoscopic gastrostomy (PEG) tube dependence at 7 months
Predictors of PEG dependency:
(1) superior constrictor dose (SC D) mean in Gy (OR 1.003)
(2) larynx V50 (volume of larynx receiving a radiation dose >= 50 Gy) in percent (OR 1.042)
(3) symptomatic before IMRT (OR 3.6)
(4) female sex (OR 4.0)
where:
• The risk for V50 starts to shoot up after 40% in Figure 3. The cutoff of 92% is given on page 302.
• The SC D mean cutoff is given as 67.6 Gy on page 302.
The authors hypothesized that fibrosis of the constrictors and larynx are the main cause for the PEG tube dependency.
