Analysis of the response time to involved-field radiotherapy in primary gastrointestinal low-grade B-cell lymphoma

Abstract

Background: Early-stage primary gastrointestinal (GI) low-grade B-cell lymphoma shows good therapeutic response to primary radiotherapy. However, there is no clear guideline for the evaluation of response to radiation therapy currently. The aim of this study was to analyze the relationship between the best response time and the clinical course after radiotherapy. Methods: Patients who underwent radiotherapy for treatment of primary GI low-grade B-cell lymphoma from September 2007 to December 2018 at Seoul St. Mary's Hospital were included. Early responders were defined by best response within 6 months after radiotherapy, and delayed responders after 6 months. Clinical and pathological factors associated with delayed response and survival analyses were performed to investigate the recurrence and survival during follow-up. Results: A total of 43 patients were evaluated and the number of gastric mucosa-associated lymphoid tissue and duodenal follicular lymphoma was 36 and 7, respectively. All of 43 patients showed complete remission to radiotherapy and the best response time after radiotherapy was a median of 3 months. There were 8 delayed responders with a median duration of 8.9 months. Early and delayed responders were characterized by a significant difference in depth of invasion beyond the mucosal layer. Conclusions: Delayed responders did not show differences in oncological outcomes compared with early responders. They were allowed to watch and wait for an additional 6 to 12 months without further treatment. Background Gastrointestinal (GI) lymphoma is the most common extranodal lymphomas and primary GI lymphoma is usually diagnosed in the stomach, duodenum, esophagus and rectum [1, 2]. More than 90% of all GI lymphomas are of B-cell lineage and treatment modalities differ according to the pathological subtype [3]. Systemic involvement of Bcell lymphomas in early stage with low-grade pathology such as mucosa-associated lymphoid tissue (MALT) or follicular lymphoma is rare and it can be cured by local radiotherapy or observed without treatment. Factors known to cause primary GI lymphoma include bacterial infections such as H.pylori and C.jejuni, preexisting intestinal diseases, and immunosuppression [4]. In the case of gastric lymphoma infected with H.pylori, H.pylori eradication (HPE) consisted of proton pump inhibitors, amoxicillin, and clarithromycin is the primary treatment resulting in an efficacy of over 80% [5, 6]. Involved-field radiotherapy (IFRT) is indicated for patients with H.pylori-positive lymphoma refractory to

Definitive Radiotherapy for Stage I Gastric Mucosa-Associated Lymphoid Tissue Lymphoma: A Retrospective Cohort of Unique-Dose Administration of 30 Gy in 15 Fractions and Analysis of Remission Duration

“…Moreover, there is currently no universally established protocol outlining the recommended time intervals and frequency of follow-up for individuals who underwent radiotherapy for MALT lymphoma. Choi et al reported eight patients needed over 6 months to accomplish CR after radiotherapy, among 43 patients who underwent definitive radiotherapy for MALT lymphoma [ 9 ].…”