The Outcome of Limited-Stage Plasmablastic Lymphoma Treated With and Without Radiation Therapy: A Single-Institutional Experience

Abstract

Purpose/Objective(s): To quantify the risks of acute and late ophthalmic toxicity in lymphoma patients receiving radiation therapy (RT) to ocular or periorbital structures, and to identify dosimetric factors predictive of these risks. Materials/Methods: The study population included 30 consecutive lymphoma patients who received radiation therapy to ocular or periorbital structures at our institution from 2004 to 2010. Dose-volume histograms and dosimetric data were generated for the lacrimal glands, lenses, globes and orbits bilaterally. Radiation-related toxicities including conjunctivitis, xerophthalmia and cataracts were collected from the medical record and adverse effects were graded using the Common Terminology Criteria for Adverse Events (CTCAE) v4.0. Descriptive statistics were used to characterize dosimetric factors and the distribution of toxicities. Results: The median age at diagnosis was 65 (range, 31 to 89). Marginal zone lymphoma was the most common histology (10 cases), followed by diffuse large B-cell lymphoma (6 cases). 11 patients (37%) received treatment to the bilateral orbits. 3D conformal therapy was used in all cases, including intensity-modulated radiation therapy in 3 cases. The median prescribed dose was 2750 cGy (range, 1980 cGy to 5000 cGy). At a median follow up of 51 months, there were no local relapses. Within the first 6 months after initiating radiation therapy, 3 patients (10%) experienced grade 2 ophthalmic toxicity comprising acute conjunctivitis or xerophthalmia. Beyond 6 months, 17 patients (57%) subsequently manifested late grade 2 toxicity comprising xerophthalmia requiring intervention or cataracts requiring surgery. There was no correlation between maximum lens dose (range 7 cGy e 3967 cGy) and the development of cataracts in the study cohort (p Z 0.42). Beyond 6 months, the lacrimal gland V5 and globe V10 were significantly correlated with the development of late xerophthalmia and grade 2 toxicity. V5 covering the entire (100%) lacrimal gland and V10 covering the entire globe were associated with late xerophthalmia (p Z 0.03 and p Z 0.006, respectively) and with the development of grade 2 toxicity (p Z 0.003 and p Z 0.005, respectively). The median globe V10 was 39.8% for patients without late xerophthalmia, in contrast to 100% for those who did develop late xerophthalmia (p Z 0.006). Conclusions: In patients receiving radiation therapy for ocular adnexal or periorbital lymphoma, attempts to spare part of the lacrimal gland and limit the globe V10 to less than 40% may reduce the risk of late xeropthalmia. Author Disclosure: L.Z. Braunstein: None. Y. Chen: None. S.W. Lee: None. P.M. Mauch: None. A.K. Ng: None.