Appropriate treatment of the lower neck when using IMRT is controversial. Our study tried to determine differences in clinical outcomes using IMRT or a standard LNF to treat low neck.
Methods and Materials
This is a retrospective, single institution study. Ninety-one patients with squamous cell carcinoma of head and neck cancer were treated with curative intent. Based on physician preference, some patients were treated with LNF (PTV3) field using a single anterior photon field matched to the IMRT field. Field junctions were not feathered. The endpoints were time to failure and use of PEG tube (as a surrogate of laryngeal edema causing aspiration) and analysis done with chi-square and the log-rank tests.
Median follow up 21 months (range 2 – 89). The median age 60 years. Thirty seven (41%) were treated with LNF, 84% were stage III or IV. PEG tube was required in 30% as opposed to 33% without the use of LNF. N2 or 3 neck disease was treated more commonly without a LNF (38% vs. 24%, p = 0.009). Failures occurred in 12 patients (13%). Only one patient treated with LNF failed regionally, 4.5 cm above the match line. The 3-year disease-free survival rate was 87%, 79% with LNF and without LNF respectively (p = 0.2) and the 3-year LR failure rate was 4%, 21% respectively, (p = 0.04).
Using LNF to treat the low neck did not increase the risk of regional failure “in early T& early N diseases” or decrease PEG tube requirements.