Objective: Our goal was to evaluate tumor response and safety in patients with locally advanced head and neck cancer treated with a novel radiation technique.

Methods: From 2010 to 2020, 8 patients (6 females, 2 males) with advanced head and neck cancer were treated using Lattice radiotherapy (LRT) at our Center.  Ages ranged from 43 to 92 with a median age of 68.  All patients had voluminous tumors located in the oral cavity (2), nasopharynx (1), neck lymph nodes (2), and maxillary antrum (3). None of the patients were candidates for conventional treatment.  All patients were treated on a compassionate protocol with palliative intent. In 6 patients the treatment consisted of either 1 or 3 LRT fractions of 10 Gy to 15 Gy per fraction.  After the LRT, all these patients continued with conventional radiation: 25 to 33 daily fractions of 1.8 Gy to 2 Gy.  In the 2 more advanced remaining patients 5 fractions of LRT/SBRT were delivered. Tumor volume ranged from 22.4 cc to 196.7 cc, with a median of 78.6 cc. The median sphere equivalent diameter was 5.1 cm.  The Dose scheme was chosen considering patient's age, stage and general condition.

Results: Overall survival ranged from 0 to 49 months with a median of 12 months. Three patients are currently alive and NED at 11, 13, and 49 months, respectively. Of the 5 deceased patients, 2 died of distant metastasis with local control of the treated site. The other three had a partial response. The two male patients died of cardiac arrest one month after completion of treatment. One patient died of unknown causes.

Conclusion: Our early experience with Lattice radiotherapy (LRT) in locally advanced, voluminous head and neck cancer appears safe and effective while delivering high doses of radiation.  Future studies using LRT for advanced head and neck cancer are needed.  Prospective research studies appear warranted.