Radiotherapy of extranodal low-grade follicular and marginal zone lymphomas: long-term follow-up of 159 patients.

OBJECTIVE: To evaluate clinical, histopathologic, and radiation (RT) dose parameters in patients with extranodal low-grade (ENLG) non-Hodgkin lymphoma (NHL) and their possible impact on local control (LC) and survival. MATERIALS AND METHODS: The medical records of 159 patients with 181 histologically confirmed ENLG-NHL lesions treated at our institution were reviewed retrospectively. RESULTS: The predominant histological subtype (73%) was marginal zone lymphoma (MZL). Common lesion sites were the gastrointestinal tract (GIT; 33%), skin (26%), and orbit (21%). The majority of patients (88%) presented with stage I/II disease. Thirty-three (20%) lesions were treated with reduced-dose RT (≤30.6 Gy) and 148 lesions (80%) with conventional-dose RT (>30.6 Gy), with an overall median dose of 39.6 Gy (range 4-63). The median follow-up period was 72 months. The 10-year local control (LC), Progression-free survival (PFS), and overall survival (OS) rates were 96, 65, and 82%, respectively. Higher overall response rate (ORR; 98% vs. 94%, p = 0.001) and complete response rate (CRR; 95% vs. 73%, p = 0.001) were observed in patients treated with conventional-dose regimens than in those treated with reduced-dose regimens. Ten-year PFS (p = 0.90) and OS (p = 0.40) was similar between the two dose groups. RT was well tolerated in both dose groups, with no grade 4/5 toxicities. In the multivariate analysis, RT dose and timing (upfront or salvage) were related to LC, whereas age, histology, and complete response (CR) to RT were associated with PFS. Patient age and radiation field size impacted OS. CONCLUSION: RT is an effective and curative local treatment for early-stage FL and MZL at conventional and reduced radiation doses. Conventional-doses seems to be associated with local response improvement, without significant differences in PFS rates. Age, histology, and response to RT may influence the PFS.

Intensity-modulated Radiotherapy in Patients With Aggressive Extranodal Non-Hodgkin Lymphoma of the Head and Neck.

BACKGROUND/AIM: Image-guided intensity-modulated radiotherapy (IG-IMRT) is increasingly being used to treat patients with head and neck malignancies. This analysis compared conventional radiotherapy (CRT) and IMRT outcomes for head and neck aggressive extranodal non-Hodgkin lymphomas (EN-NHL). PATIENTS AND METHODS: Forty-eight patients who underwent irradiation between 2005 and 2019 were identified. RESULTS: The median follow-up was 42 months. Patients treated with IMRT experienced higher overall responde rate than patients who received 3DCRT (85% vs. 73%, p=0.4). There was non-significant longer survival following IMRT compared with 3DCRT in terms of 5-year OS (p=0.16). Complete responders after primary treatments had a significantly higher 5-year progression-free (p<0.001) and overall survival (p=0.003) in comparison with those without a complete response. Regarding toxicities, IMRT was associated with less acute and chronic adverse events. CONCLUSION: IG-IMRT following systemic therapy seems to be associated with a favorable survival and toxicity profile in patients with EN-NHL.