Fig 1.
Flow-diagram of study selection and inclusion in the systematic review and meta-analyses as per PRISMA guidelines.
Table 1.
Characteristics of studies included in the systematic review and meta-analyses.
Table 2.
Summary of clinical outcomes of studies included in the systematic review and meta-analyses.
Fig 2.
Forest plot (including the risk of bias assessment) demonstrating significant reduction in the risk of acute grade 2 or worse xerostomia with intensity modulated radiation therapy (IMRT) compared to conventional techniques.
Note comparable benefit of IMRT over two-dimensional radiotherapy (2D-RT) and three-dimensional radiotherapy (3D-RT) on subgroup analyses.
Fig 3.
Forest plot (including the risk of bias assessment) demonstrating significant reduction in the risk of late grade 2 or worse xerostomia with intensity modulated radiation therapy (IMRT) compared to two-dimensional/three-dimensional radiotherapy (2D/3D-RT).
Note the consistent and persistent benefit of IMRT over time on subgroup analyses.
Fig 4.
Forest plot (including the risk of bias assessment) demonstrating non-significant reduction in the risk of loco-regional relapse with intensity modulated radiation therapy (IMRT) compared to two-dimensional/three-dimensional radiotherapy (2D/3D-RT).
On subgroup analyses, patients with nasopharyngeal cancers demonstrate significantly improved loco-regional control (LRC) with IMRT compared to conventional techniques, while there is no significant difference in LRC between IMRT and 2D/3D-RT for patients with cancers of the laryngo-pharynx.
Fig 5.
Forest plot (including the risk of bias assessment) demonstrating significant reduction in the risk of death with intensity modulated radiation therapy (IMRT) compared to two-dimensional/three-dimensional radiotherapy (2D/3D-RT).
On subgroup analyses, patients with nasopharyngeal cancers demonstrate significantly improved overall survival (OS) with IMRT compared to conventional techniques, while there is no significant difference in OS between IMRT and 2D/3D-RT for patients with cancers of the laryngo-pharynx.