Results of Radiation Therapy for Primary Extranodal Lymphoma of the Head and Neck: A Report of Case Series

Radiation therapy is an important treatment modality for the extra-nodal lymphoma (ENL) of the head and neck. Intensity Modulated radiation therapy (IMRT) has been shown for head and neck cancers to be associated with decreased late side effects like Xerostomia compared with conventional RT techniques (Conv.RT). The purpose of the study is to determine the clinico-pathological features, treatment outcomes and late toxicities in patients (pts) with ENL of head and neck treated with different RT techniques.

Retrospective review of records from 2007–2010 identified 14 pts with ENL of the head and neck treated with RT at Fox Chase Cancer Center. Eight were treated with IMRT and 6 with conventional RT technique. Thirteen had CD20+ non-Hodgkin lymphoma [NHL; 7 diffuse large B cell (DLBCL), 3 MALT, 3 others], and one Hodgkin's lymphoma (HL; classic). All pts underwent routine staging work-up with negative bone marrow biopsy for all. Pre and post-treatment PET scans were done in 7 pts. Initial chemotherapy (R-CHOP × 4–6 courses for DLBCL, ABVD × 4 for HL), or no chemotherapy (MALT) was followed by involved field radiation therapy (median RT dose: 36 Gy for NHL, 30 Gy HL, 150– 180 cGy per fraction in 20 fractions over 4 weeks).

The median follow up was 28 months (range: 1– 52). The median age was 60 years (range: 42–95; 7 males and 7 female). Nine had stage IEA disease, 3 had stage II and 2 stage IV. Five had oropharynx involvement, two had paranasal sinus (DLBCL) 2 nasopharynx (1 DLBCL, 1 MALT) and 1 vallecula (HL). The overall response rate after combined modality treatment was 100%. There were no FDG avid lesion noted on post-treatment PET. There were no local or neck node relapses at last follow up. The 2-year actuarial survival rate was 80%. One DLBCL patient had systemic relapse involving stomach and bilateral testes, was treated with second-line chemotherapy and radiation therapy. At the last follow up, 12/14 were alive. RTOG grade 2 acute skin changes were noted in 6 pts (3 by each RT technique), grade 2 mucositis in 5 pts (3 with Conv.RT) and grade 2 xerostomia in 6 pts. None of the pts developed grade 3 xerostomia (both acute and late). Late grade 2 Xerostomia was seen in 5 pts treated with Conv.RT but not with IMRT.

RT following chemotherapy or used alone in ENL of head and neck was associated with local and distant disease control in the majority of patients, with a toxicity profile that appears favorable for IMRT compared with conventional radiotherapy techniques. Larger studies are required to confirm that IMRT is as effective as conventional involved-field RT.

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