1. Response-Adapted Ultralow-Dose Radiation Therapy for Orbital Indolent B-Cell Lymphoma: A Phase 2 Nonrandomized Controlled Trial.
- Author
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Pinnix CC, Dabaja BS, Gunther JR, Fang PQ, Wu SY, Nastoupil LJ, Strati P, Nair R, Ahmed S, Steiner R, Westin J, Neelapu S, Rodriguez MA, Lee HJ, Wang M, Flowers C, Feng L, and Esmaeli B
- Subjects
- Humans, Female, Male, Middle Aged, Aged, Adult, Aged, 80 and over, Prospective Studies, Treatment Outcome, Radiotherapy Dosage, Lymphoma, Orbital Neoplasms radiotherapy, Orbital Neoplasms mortality, Orbital Neoplasms pathology, Lymphoma, B-Cell radiotherapy, Lymphoma, B-Cell mortality, Lymphoma, B-Cell pathology
- Abstract
Importance: Radiation therapy to doses of 24 to 36 Gy is currently used to treat indolent B-cell lymphoma of the ocular adnexa; however, ocular adverse effects are common., Objective: To determine if a response-adapted radiation therapy strategy will result in excellent disease outcomes while reducing orbital morbidity., Design, Setting, and Participants: This single-institution, phase 2 prospective nonrandomized controlled trial of a response-adapted strategy involved 50 evaluable patients with stage I to IV indolent B-cell lymphoma of the ocular adnexa enrolled between July 2015 and January 2021. This treatment approach was also retrospectively evaluated with a separate 55-patient cohort treated between March 2013 and October 2021. All data were analyzed between November 2021 and December 2023., Interventions: Patients were treated with ultralow-dose radiation therapy to 4 Gy in 2 fractions and assessed for response at 3-month intervals. Patients with persistent orbital lymphoma were offered an additional 20 Gy in 10 fractions to complete the response-adapted treatment., Main Outcome and Measures: The primary end point was 2-year local orbital control within the irradiated field after response-adapted therapy. Secondary end points included overall survival and complete response rate., Results: The 50 prospective patients were a median (range) of 63 (29-88) years old, and 31 (62%) were female. Among the 50 patients, 32 (64%) had mucosa-associated lymphoid tissue lymphoma, 12 (24%) had follicular lymphoma, and 6 (12%) had unclassifiable low-grade B-cell lymphoma. Thirty-one patients (62%) had stage I disease, and 36 (72%) were newly diagnosed. At a median follow-up of 37.4 (95% CI, 33.7-52.5) months, the 2-year local control rate was 89.4% (95% CI, 81.0%-98.7%), and the 2-year overall survival rate was 98.0% (95% CI, 94.1%-100%); 45 patients (90.0%; 95% CI, 78.2%-96.7%) experienced a complete response to response-adapted radiation, including 44 patients with a complete response to ultralow-dose radiation and 1 patient with a complete response after an additional 20 Gy. No local recurrences were observed among patients with a complete response to response-adapted therapy. No grade 3 or higher toxic effects were observed. In a planned subset analysis of 22 patients with newly diagnosed, untreated stage I mucosa-associated lymphoid tissue lymphoma, the 2-year local control rate was 90.7% (95% CI, 79.2%-100%), and the 2-year freedom from distant relapse rate was 95.2% (95% CI, 86.6%-100%)., Conclusion and Relevance: In this nonrandomized controlled trial, response-adapted ultralow-dose therapy for indolent orbital B-cell lymphoma resulted in reduced radiation exposure, negligible toxic effects, and excellent disease outcomes., Trial Registration: ClinicalTrials.gov Identifier: NCT02494700.
- Published
- 2024
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