title: Decreased radiation doses to tongue with "stick-out" tongue position over neutral tongue position in head and neck cancer patients who refused or could not tolerate an intraoral device (bite-block, tongue blade, or mouthpiece) due to trismus, gag reflex, or discomfort during intensity-modulated radiation therapy.
abstract: OBJECTIVE
  To assess changes in oral cavity (OC) shapes and radiation doses to tongue with different tongue positions during intensity-modulated radiation therapy (IMRT) in patients with head and neck squamous cell carcinoma (HNSCC) but who refused or did not tolerate an intraoral device (IOD), such as bite block, tongue blade, or mouthpiece.
  
  
  RESULTS
  Tongue volume outside of OC was 7.1 ± 3.8 cm3 (5.4 ± 2.6% of entire OC and 7.8 ± 3.1% of oral tongue) in IMRT-S. Dmean of OC was 34.9 ± 8.0 Gy and 31.4 ± 8.7 Gy with IMRT-N and IMRT-S, respectively (p < 0.001). OC volume receiving ≥ 36 Gy (V36) was 40.6 ± 16.9% with IMRT-N and 33.0 ± 17.0% with IMRT-S (p < 0.001). Dmean of tongue was 38.1 ± 7.9 Gy and 32.8 ± 8.8 Gy in IMRT-N and IMRT-S, respectively (p < 0.001). V15, V30, and V45 of tongue were significantly lower in IMRT-S (85.3 ± 15.0%, 50.6 ± 16.2%, 24.3 ± 16.0%, respectively) than IMRT-N (94.4 ± 10.6%, 64.7 ± 16.2%, 34.0 ± 18.6%, respectively) (all p < 0.001). Positional offsets of tongue during the course of IMRT-S was -0.1 ± 0.2 cm, 0.01 ± 0.1 cm, and -0.1 ± 0.2 cm (vertical, longitudinal, and lateral, respectively).
  
  
  METHODS
  13 patients with HNSCC underwent CT-simulations both with a neutral tongue position and a stick-out tongue for IMRT planning (IMRT-N and IMRT-S, respectively). Planning objectives were to deliver 70 Gy, 63 Gy, and 56 Gy in 35 fractions to 95% of PTVs. Radiation Therapy Oncology Group (RTOG) recommended dose constraints were applied. Data are presented as mean ± standard deviation and compared using the student t-test.
  
  
  CONCLUSIONS
  IMRT-S for patients with HNSCC who refused or could not tolerate an IOD has significant decreased radiation dose to the tongue than IMRT-N, which may potentially reduce RT related toxicity in tongue in selected patients.
authors.affiliation: Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, USA.
authors.forename: Whoon Jong
authors.initials: WJ
authors.lastname: Kil
authors.affiliation: Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Kulasekere
authors.affiliation: Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, USA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Derrwaldt
authors.affiliation: Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, USA.
authors.forename: Jacob
authors.initials: J
authors.lastname: Bugno
authors.affiliation: Cleveland Veterans Affairs Medical Center, Cleveland, Ohio, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Hatch
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D005683:Gagging; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008397:Masks; D009055:Mouth / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects; D009064:Mouth Protectors; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D014055:Tomography, Emission-Computed / Q000379:methods; D014059:Tongue / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects; D014313:Trismus / Q000473:pathology
keywords: IMRT; customized immobilization mask; head and neck cancer; oral cavity; tongue position