Postage stamps are so last century.

We’ve been following the expanding DAHANCA 5+5 approach to target volume delineation in head and neck cancer, meaning a 5 mm expansion from GTV to a high-risk CTV and then another 5 mm expansion to an intermediate-risk CTV. The 5+5 approach makes some people nervous, especially in the larynx which is still routinely treated with opposed lateral fields. This paper reports the Princess Margaret experience transitioning to intensity modulated radiation (IMRT) for T2N0 larynx cancer. In parallel, they also transitioned to DAHANCA-style regimens of 6 fractions per week. The 5+5 CTVs were cropped at cartilage before a PTV expansion of 5 mm radially and 1 cm sup/inf (for normal laryngeal mobility). Image guidance evolved from spine bony alignment using portal imaging to laryngeal soft-tissue alignment using daily cone-beam CT. Over this short transition period from 2006 to 2013, rates of local control at 3 years increased from 70% to nearly 90%, which is certainly an improvement to write home about. TBL: The authors attribute increased efficacy and reduced toxicity with definitive radiation for early-stage laryngeal cancer to partial-larynx volumes using accelerated fractionation and soft-tissue alignment. | Rock, Int J Radiat Oncol Biol Phys 2018