Skinny love.

Top Line: Post-op radiation for resected cutaneous squamous cell carcinoma (cSCC) isn’t called for all that often.

The Study: So knowing what volumes and margins to employ in the head and neck (H&N) regions can be tricky...until now. Here are international guidelines on post-op radiation contouring and dosing for H&N cSCC. First things first, IV contrast with wiring of all scars at time of sim with plan for an IMRT approach with daily image guidance is generally called for to deliver adequate dose to the target while sufficiently sparing organs at risk. If pre-op imaging is available, it should be fused to ensure the space previously occupied by gross tumor and/or nodal disease is included in the high-risk volume. To create the high-risk clinical target volume (CTV) this should be expanded by 5 mm, cropped from anatomical boundaries, and expanded even further if needed to include the entire post-op bed and/or neck dissection / parotidectomy bed or involved ipsilateral neck level. The low-risk CTV can include any flap or graft tissue as well as adjacent non-dissected clinically uninvolved nodal regions. Finally, you can include a third boost volume for areas of positive or close (≤2 mm) margins. The recommended doses for boost, high-risk, and low-risk targets, respectively, are 63, 60, and 56 Gy all in 30 fractions. What’s more, they offer a method of “zoning” perineural spread (see Table 5) to showcase which segments of involved large nerves should be included in the high- and low-dose volumes.

TBL: This paper and its myriad tables and figures are worth a bookmark for reference during your next post-op H&N cSCC case. | Porceddu, Int J Radiat Oncol Biol Phys 2020