Intraoperative radiation therapy for locally advanced and recurrent head and neck cancer

Abstract

The purpose of the present study was to present a single institution experience with intraoperative radiation therapy (IORT) for patients with head and neck cancer (HNC). The present study included all patients with HNC treated consecutively with IORT at Loyola University Medical Center between January 2014 and December 2018. Charts were reviewed for patient and tumor characteristics, IORT technical details, IORT-induced adverse events and treatment outcomes. The study included 23 eligible patients. Median patient age was 66 years (range, 34-91 years). Tumor sites included the parotid gland (43%), lymph nodes (43%), oral tongue (9%) and ear (4%). A total of 48% of patients received IORT upfront with or without postoperative adjuvant external beam radiation therapy (EBRT), whereas 52% received salvage IORT after local tumor recurrence. The median prescribed IORT dose was 7.5 Gy (range, 5-14 Gy) in a single fraction prescribed to 5 mm depth with flat applicators (median diameter, 5 cm). A total of 92% of patients did not experience wound healing complications. One patient (4%) developed postoperative acute thromboembolic stroke and a second patient (4%) experienced protracted wound healing. At a median follow up of 36 months (range, 2-81 months), overall survival was 52%. In addition, 48% of patients were reported to have no evidence of disease, and although two had died of unrelated causes, 13% of patients were alive with disease and 39% died with the disease. The local-regional recurrence rate was 39% (median time to local recurrence, 11 months; range, 1-34 months), the rate of distant metastasis was 35% (median time to distant metastasis, 16 months; range, 4-40 months), and 21% of patients had both local-regional recurrence and distant metastases. The percentages of local-regional recurrence and distant metastases among patients receiving salvage IORT were 58 and 50% respectively, compared with 18 and 18% respectively in those receiving upfront IORT with or without adjuvant EBRT. In the present single institution retrospective study, it was concluded that IORT for patients with locally advanced and recurrent HNC was a safe treatment modality, with tumor control comparable to historical IORT data. Larger prospective studies are needed to further assess the utility of IORT in the management of locally advanced and recurrent HNC.

Keywords: INTRABEAM; IORT; head and neck cancer; orthovoltage; patient outcome.

Figure 1

INTRABEAM device and stand. The insert shows an example flat applicator.

Figure 2

(A) K-M curves showing overall survival. (B) K-M curves showing survival in patients who received upfront vs. salvage IORT. (C) K-M curves showing survival per original disease site; other sites include parotid (n=11), tongue (n=2) and ear (n=1). (D) K-M curves showing recurrence free survival per original disease site. K-M, Kaplan-Meier; IORT, intraoperative radiation therapy.

Figure 3

Local-regional control and incidence of distant metastases after IORT. (A) Overall incidence of local-regional recurrence or distant metastasis. (B) Incidence for upfront vs. salvage IORT. H&N, head and neck; IORT, intraoperative radiation therapy.