ESTRO 2024 - Abstract Book

S1144

Clinical - Haematology

ESTRO 2024

1037

Digital Poster

Radiotherapy for mucosa-associated lymphoid tissue lymphoma: experience of a single institution

Celia Nicolás-Boluda 1 , Gemma Alberca 1 , Manuel E. Luna 1 , Adelaida Nieto 1 , Orlanda Alonso 1 , Norma C. Gutiérrez 2 , Julio A. Ramos 3 , Luis A. Pérez-Romasanta 1 1 Complejo Asistencial Universitario de Salamanca, Radiation Oncology, Salamanca, Spain. 2 Complejo Asistencial Universitario de Salamanca, Haematology, Salamanca, Spain. 3 Complejo Asistencial Universitario de Salamanca, Physics and Radiation Protection, Salamanca, Spain

Purpose/Objective:

Extranodal marginal zone lymphoma (EMZL) is an indolent non-Hodgkin´s B-cell lymphoma (NHBCL) which belongs to the heterogeneous group of MZLs, beside splenic and nodal MZL. EMZL can develop from mucosal, known as mucosa-associated lymphoid tissue (MALT) lymphoma; and non-mucosal sites such as the stomach, bronchi, thyroid gland, liver, kidney, orbit, or skin. Gastric MALT-lymphoma accounts for 30-50% of all MALT-lymphoma locations; the orbit/orbital adnexa represents 8% of all EMZL and primary thyroid lymphoma (PTL) is less frequent, 1-2%. On the other hand primary cutaneous MZL accounts for 20 – 40% of all primary cutaneous B-cell lymphoma. In most of the cases, gastric MALT lymphoma is associated with an Helicobacter pylori infection; this is why first-line treatment of stage IE and IIE localized gastric MALT lymphoma is based on the erradication of H.pylori . In other sites, combination therapy such as R-CHOP, surgery, or radiotherapy (RT) are considered first-line treatments.

We know that indolent NHLs are sensitive to moderate doses of RT, the recommended dose in EMZL with demonstrated safety and response is 30Gy.

Given that MALT lymphoma is rare, treatment recommendations are based on studies with low levels of evidence. The present study aimed to assess the effectiveness of radiotherapy in the cases treated in our institution.

Material/Methods:

Data were collected from 117 patients with anatomopathological diagnosis of EMZ B-cell lymphoma from 1996 2022.

Oncohaematological history, age, location, treatment received, local tumor control and current status were analysed.

Results:

Twelve patients (10.3%) were treated with RT. Mean age of EMZL diagnosis was 55.9 years. Lymphoma was located in the orbital area in 42% of the patients, five patients had gastric affection, one patient was treated of a lesion on