High Local Control and Under-Reported Ophthalmologic Toxicity Using “Boom-Boom” Radiation Therapy for Indolent Orbital Lymphoma

Committee/Faculty

Presenting Author(s)

SS

Sanjna Shelukar, n/a

BS
Thomas Jefferson University Hospital, Department of Radiation Oncology
Blue Bell, Pennsylvania, United States

Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.

Co-Author(s)

CF

Christian Fernandez

MD
Thomas Jefferson University Hospital, Department of Radiation Oncology
Chicago, Illinois, United States

Disclosure: Disclosure information not submitted.
ZB

Zeynep Bas

MD
Wills Eye Hospital, Ocular Oncology Service
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
LK

Lydia Komarnicky

MD
Thomas Jefferson University Hospital, Department of Radiation Oncology
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
SL

Sara Lally

MD
Wills Eye Hospital, Ocular Oncology Service
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
CS

Carol Shields

MD
Wills Eye Hospital, Ocular Oncology Service
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
AB

Adam Binder

MD
Thomas Jefferson University Hospital, Department of Medical Oncology
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
PP

Pierluigi Porcu

MD
Thomas Jefferson University Hospital, Department of Medical Oncology
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
SA

Seyfettin Alpdogan

MD
Thomas Jefferson University Hospital, Department of Medical Oncology
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
UM

Ubaldo Martinez-Outschoorn

MD
Thomas Jefferson University Hospital, Department of Medical Oncology
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.
WS

Wenyin Shi, Co-Director, Brain Tumor Center of the Sidney Kimmel Cancer Center Co-Director, Stereotactic Radiosurgery Program

MD-PHD
Thomas Jefferson University Hospital
Philadelphia, Pennsylvania, United States

Disclosure: Disclosure information not submitted.

Purpose: The standard of care for early-stage indolent B-cell lymphoma is radiation therapy (RT) with 24 Gy in 12 fractions. However, orbital structures are uniquely sensitive to radiation with increased risk of toxicities even at the lower doses of this regimen (1). Low dose RT using 4 Gy in 2 fractions (colloquially referred to as “Boom-Boom”) has demonstrated high rates of local control with negligible toxicity, and is an attractive and convenient option for orbital lymphoma patients. We reviewed the utility of Boom-Boom RT for indolent orbital lymphoma with an emphasis on ophthalmologic toxicity.

Methodology: Patients treated at Thomas Jefferson University between 2010 and 2021 for indolent orbital lymphomas using 4 Gy in 2 fractions were identified. Records from medical oncology, radiation oncology, and ophthalmology were reviewed. Descriptive analysis of patient, disease, and treatment characteristics was performed. Endpoints of interest included local control, progression, and ocular toxicity as per oncologist Common Terminology Criteria for Adverse Events (CTCAE) and ophthalmology reports including best corrected visual acuity (BCVA) changes, dry eyes, cataracts, retinopathies, and glaucoma.

Results: 26 distinct orbits in 24 patients were identified, of which 18 orbits in 16 patients had follow-up. The median patient age was 65 years (range 24-80 years), 54% (n=13) were female, and median Karnofsky Performance Scale (KPS) was 90% (range 100%-80%). There were 96% (n=23) patients with early Lugano stage disease, 67% (n=10) with baseline ocular data had no prior ocular history, and 8% (n=2) had chemotherapy prior to RT. Median follow-up was 12 months (range 2-52 months). Complete, partial, and stable response was achieved in 69%, 19%, and 12% of patients, respectively. At 1-year, local and distant progression rates were 6% and 19%, with an overall median time to progression of 47 and 4 months, respectively. Of those with local progression, 100% (n=1) was salvaged with 24 Gy in 12 fractions.
Oncologists reported 4% and 0% CTCAE grades 1 and 2+ toxicities, respectively. However, 9 patients whose ophthalmology follow-up records were available showed 33% (n=3) of patients with new post-RT complications including dry eye (11%), cataract (11%), and chorioretinal atrophy (11%). There were no eyes with significant loss of BCVA after RT.

Conclusions: Boom-Boom RT provides excellent control rates for indolent orbital lymphoma, with local recurrences salvageable with 24 Gy in 12 fractions. While minimal toxicity was documented by treating radiation oncologists, higher rates were noted by ocular oncologists, highlighting the radiosensitivity of orbital structures, and potentially underreported ocular toxicity in both Boom-Boom RT and the standard regimens. Patients with indolent orbital lymphoma should be considered for Boom-Boom RT.

References: 1. Jeganathan VSE, Wirth A, MacManus MP. Ocular risks from orbital and periorbital radiation therapy: A critical review. Int J Radiat Oncol. 2011;79(3):650-9.