Analysis of Chronic Kidney Disease After Radiation Therapy for Gastric/Duodenal Mucosa-Associated Lymphoid Tissue Lymphoma

PURPOSE: This study aimed to evaluate the relationship between chronic kidney disease (CKD) after radiation therapy for gastric/duodenal mucosa-associated lymphoid tissue lymphoma and dose-volume histogram of the kidneys. METHODS AND MATERIALS: We retrospectively reviewed 40 patients who received 3-dimensional conformal radiation therapy. CKD was evaluated using the Common Terminology Criteria for Adverse Events version 5.0. The mean dose of bilateral kidneys/right kidney/left kidney (D(mean of b-kidneys)) (D(mean of r-kidney)) (D(mean of l-kidney)), bilateral kidneys/right kidney/left kidney volume receiving ≥ x Gy (V(x of b-kidneys)) (V(x of r-kidney)) (V(x of l-kidney)), and patients’ baseline clinical characteristics were analyzed. RESULTS: The median radiation therapy dose was 28 (range, 24-44.8) Gy in 14 fractions. The median follow-up period was 63.1 months, and the 5-year cumulative incidence of grade 2 CKD rate was 14.8%. Among several factors, V(5 of b-kidneys) was most strongly associated with grade 2 or worse CKD, with an area under the curve of 0.81 in the receiver operating characteristic curve. The 5-year incidence rate in patients with V(5 of b-kidneys) ≥ 58% was significantly higher than that in other patients (24.5% and 9.8%, respectively; P < .05). CONCLUSIONS: In this study using 3-dimensional conformal radiation therapy, the rate of adverse events at 5 years was low, many patients showed toxicity after 5 years; thus, continuous follow-up is necessary to detect potential nephrotoxicity. Our data demonstrate that V(5 of b-kidneys) was most strongly associated with the risk of CKD. With lower doses and more advanced techniques in recent years, the incidence of CKD may be further reduced.