Radiation Oncology/Toxicity/Dysphagia

Dysphagia

MDACC; 2012 PMID 20646872 -- "Candidate dosimetric predictors of long-term swallowing dysfunction after oropharyngeal intensity-modulated radiotherapy." (Schwartz DL, Int J Radiat Oncol Biol Phys. 2010 Dec 1;78(5):1356-65.)
- Dose volume constraints for anterior oral cavity (V30 < 65% and V35 < 35%) and superior sub-region of the superior phayngeal constrictor (V55 < 80% and V65 < 30%) were predictive for swallowing dysfunction.

UC Davis; 2010 (2002-9) PMID 20231073 -- "Evaluating the role of prophylactic gastrostomy tube placement prior to definitive chemoradiotherapy for head and neck cancer." (Chen AM, Int J Radiat Oncol Biol Phys. 2010 Nov 15;78(4):1026-32.)
- Retrospective. 70 pts with prophylactic G-tube prior to RT, 50 without. All treated with chemo/RT.
- Median weight loss during RT: 19 lbs (GT) vs 43 lbs (no GT). 32% of pts without prophylactic G-tube required GT placement at median of 33 days from start of RT. At 6 months, median weight change -4% (GT) vs -7% (no GT). G-tube dependence at 6 months and 12 months 41% and 21% (GT) vs 8% and 0% (no GT).
- Conclusion: prophylactic G-tube effective at preventing acute weight loss and need for IV hydration, but associated with significantly higher rates of late esophageal toxicity.

Alabama; 2010 PMID 19467801 -- "Dosimetric factors associated with long-term dysphagia after definitive radiotherapy for squamous cell carcinoma of the head and neck." (Caudell JJ, Int J Radiat Oncol Biol Phys. 2010 Feb 1;76(2):403-9. Epub 2009 May 19.)
- Retrospective. 83 patients, definitive IMRT
- Predictors for PEG tube dependence and aspiration: mean larynx dose >41 Gy, larynx V60 >24%, inferior pharyngeal constrictor V60 >12%
- Predictors for pharyngoesophageal stricture: superior pharyngeal constrictor V65 >33%, middle pharyngeal constrictor V65 > 75%
- Conclusion: Dose to larynx and pharyngeal constrictors predicted long-term swallowing complications

Harvard; 2008 (2004-2006) PMID 18468812 -- "Dose to larynx predicts for swallowing complications after intensity-modulated radiotherapy." (Caglar HB, Int J Radiat Oncol Biol Phys. 2008 Nov 15;72(4):1110-8. Epub 2008 May 28.)
- Retrospective. 96 patients with H&N cancers, 85% definitive RT vs 15% postop RT. Induction chemo 29% vs. concurrent chemo 61%. Median F/U 10 months
- Outcome: Clinically significant aspiration 32% and stricture 37%. No aspiration if mean larynx dose <48 Gy or mean inferior pharyngeal constrictor dose <54 Gy. No stricture if mean inferior pharyngeal constrictor dose <54 Gy; smoking correlated significantly.
- Conclusion: Aspiration and stricture common side effects; dose limits established for larynx and inferior pharyngeal constrictors

Erasmus University Medical Center; 2007 (Netherlands)(2000-2005) PMID 17714815 -- "Dysphagia disorders in patients with cancer of the oropharynx are significantly affected by the radiation therapy dose to the superior and middle constrictor muscle: a dose-effect relationship." (Levendag PC, Radiother Oncol. 2007 Oct;85(1):64-73. Epub 2007 Aug 21.)
- 81 patients with SCC of oropharynx. 23% severe late dysphagia. Mean F/U 1.5 years IMRT and 4 years 3D-CRT
- Outcome: steep dose-effect relationship between mean dose to constrictor muscles and severe dysphagia. 70 Gy probability 40%, 50 Gy probability 20%, 22 Gy probability 2%. For each additional 10 Gy after 55 Gy, probability of dysphagia increases by 19%
- Conclusion: Dose-effect between dose and swallowing complaints observed

U. Michigan; 2004 PMID 15590174 -- "Dysphagia and aspiration after chemoradiotherapy for head-and-neck cancer: which anatomic structures are affected and can they be spared by IMRT?" (Eisbruch A, Int J Radiat Oncol Biol Phys. 2004 Dec 1;60(5):1425-39.)
- 26 pts treated with RT + gemcitabine. Prospective swallowing assessment with videofluoroscopy, endoscopy, and CT.
- Dysphagia/Aspiration Related Structures (DARS) include: pharyngeal constrictor muscles, supraglottic and glottic larynx.
- IMRT was able to reduce the V50(Gy) of the DARS.