Study Treatment Period (Year from- to) IMRT/ non IMRT: No of Patients Primary in oro pharynx IMRT/non IMRT patients Constrictors outlined as OAR? Decreased dose to constrictors with IMRT vs. CRT? % with RTOGGrade 2 or above dysphagia Video-fluroscopy to assess dysphagia Questionnaire based or rated dysphagia evaluation? Swallowing function benefit with constrictors sparing? SIGN Evidence Level Dirix et al. [27] 2006-2008 42 55 12 34 Yes Yes <5% No No No 2 Anand et al. [31] 2002-2004 62 0 10 0 Yes (only 4 patients for comparison) Yes* 12.7% at 6 months No Yes Yes 3 Bhide et al. [32] 2006-2007 37 0 7 0 Yes N/A 6.67% at 1 year No Yes No 2 Feng et al. [33] 2003-2008 73 0 73 0 Yes N/A <6% at 1 year Yes Yes Yes 2 Levendag et al. [34] 2000-2005 35 46 35 46 Yes N/A ** 23% at 3 years *** No Yes Yes 2 Schwartz et al. [35] 2008-2009 31 0 31 0 Yes Yes ….. Yes No Yes 2 Caudell et al. [36] 2001-2006 83 0 44 0 Yes Yes 14.2% at 2 Years Yes Yes Yes 2 Peponi et al. [37] 2002-2005 82 0 55 0 Yes Yes 18% at 20 months No Yes Yes 2 * Comparison done between IMRT plans with representative conformal radiotherapy plans (4 patients). More than 50% of the volume of “dysphagia related structures” received a lower mean radiation dose in the IMRT plans. * *Patients receiving brachytherapy boost received lower dose to the constrictors and a smaller volume of their constrictors was irradiated. *** Patients were treated with IMRT or 3 dimensional conformal radiotherapy (3dCRT) up to 46 Gy followed by brachytherapy boost. If ineligible for brachytherapy, patients had surgery and post operative IMRT or 3dCRT.

Table 3: Studies reporting on dysphagia scores with IMRT.