EP-1129: Radiotherapy for mucosa-associated lymphoid tissue lymphoma of the ocular adnexa
Radiotherapy and Oncology
Purpose/Objective: Radiotherapy is useful for the treatment of MALT lymphoma of the ocular adnexa and is the first choice for this disease. We investigated the long-term follow-up results of radiotherapy for MALT lymphoma of the ocular adnexa. Materials and Methods: Twenty-four patients with MALT lymphoma of the ocular adnexa were treated with radiotherapy alone. The disease arose from the conjunctiva in 18 patients (10 with bilateral involvement), and from the retrobulbar space in 6 patients
... with bilateral involvement). The median follow-up of the surviving patients was 70 months (range, 6-157). The histological diagnoses obtained via an incisional biopsy in all cases were categorized according to the criteria established by the WHO classification. During the staging work-up, gallium scans, computed tomography of the chest and abdomen, and FDG-PET were performed for all patients. Patients with I AE or I AE2 disease according to the American Joint Committee on Cancer TNM Classification were treated with radiotherapy alone. Lesions confined to the conjunctiva were treated with a single anterior direct field using a 6-12 MeV electron beam. The entire bulbar and palpebral conjunctiva were treated. Retrobulbar tumors were irradiated with 18 MeV electron or 6-MV X-rays. The clinical target volume was the entire orbital cavity. A median dose per fraction of 2.0Gy (range 1.8-2.5) was administered, with the total dose ranging between30 and 54Gy (median, 38Gy). Lead eye shields were used for radiotherapy of conjunctival lymphoma. Lens protection was not used for radiotherapy of retrobulbar lymphoma except for one patient. Results: All patients with MALT lymphoma achieved a CR or unconfirmed CR (CRu). Two patients died of other disease. One patient died of lung cancer and another patient died of progressive supranuclear palsy. The 5-and 10-year overall survival rates of all patients with MALT lymphoma were 100% and 90%, respectively. The 5-and 10-year cause-specific survival rates were 100% and 100%, respectively. Seven eye-balls developed delayed toxicity. Four eye-balls with conjunctival lymphoma experienced dry eye syndrome, and four eye-balls developed cataracts. One patient with retrobulbar lymphoma experienced both dry eye syndrome and cataracts. The vision of patients with cataracts was restored by surgery. In seven eye-balls, the radiation dose had been 40Gy or more. Conclusions: Excellent local control and survival can be achieved for patients with MALT lymphoma of the ocular adnexa using radiotherapy alone. As a dose of more than 30Gy develops dry eye syndrome or cataract, the dose must not exceed 30Gy for safe treatment of MALT lymphoma of the ocular adnexa. At present, based on our study and previous studies, we administer a radiation dose of 30.6Gy with a fraction size of 1.8Gy for MALT lymphoma of ocular adnexa treatment.