Sentinel neck.

Top Line: A lot of people are trying to find reasonable ways to reduce radiation volumes for head and neck cancer patients.

The Study: In this phase 1/2 trial, patients receiving definitive radiation for cN0 head and neck cancer (minus T1 larynx) underwent sentinel node mapping to guide radiation volumes. Importantly, everyone had PET staging. They underwent peritumoral Tc99 injection and SPECT/CT. Here’s the kicker: they did the SPECT scan after simulation and tried to have the patients lie in the scanner for several hours in their immobilization mask. This information was then used to generate a nodal clinical target volume (CTV) encompassing the nodal levels that contained the four hottest nodes. For comparison, standard nodal volumes based on primary site recommendations were generated. The volume of the sentinel CTV was roughly half that of the standard CTV, which led to a significant reduction in the dose to critical organs. When it came to nodal drainage, there was a nearly 50/50 split between unilateral and bilateral drainage. While levels II and III were most commonly involved as expected, there were several unexpected drainage patterns (e.g., level VII for tonsil and level I for soft palate).

TBL: Lymphoscintigraphy may be an interesting way to guide reduced elective neck volumes for early-stage head and neck cancer. | Longton, Int J Radiat Oncol Biol Phys 2020