S508
Clinical - Haemotology
ESTRO 2026
Digital Poster Highlight 2736
Ten studies comprising 591 patients met inclusion criteria (Figure 1).Overall response rate (ORR): 88– 100%Complete response (CR): 50–95%Local control: 63–100%2-year PFS: > 85% in most seriesNo grade ≥ 3 toxicities were observed. Mild grade 1–2 acute effects (6–42%) included dry eye and conjunctivitis; late effects (16–33%) were rare, with cataracts seldom requiring surgery. Across comparative cohorts, late ocular toxicity occurred in approximately 20% with ULD-RT versus up to 70% with 20–30 Gy regimens, indicating a fourfold reduction in clinically relevant side effects. Comparative studies confirmed similar disease control but markedly lower ocular toxicity versus conventional regimens. All studies were rated high quality (NOS ≥ 7).
Combining radiotherapy with daratumumab in multiple myeloma: a safe strategy for symptom control. Inès PETIT DE SERVINS 1 , Philippe REY 2 , Emmanuelle Nicolas-Virelizier 2 , Yann Guillermin 2 , Anne-Sophie Michallet 2 , Waisse Waissi 1 1 Radiotherapie, Centre Leon Berard, Lyon, France. 2 Hématologie, Centre Leon Berard, Lyon, France Purpose/Objective: CD38-directed monoclonal antibodies (mAbs), such as daratumumab, have become central to the treatment of multiple myeloma (MM), offering both cytotoxic and immunomodulatory effects. Radiotherapy (RT) remains a key modality for localized disease control and palliation. However, the safety of combining RT with anti-CD38 therapy remains insufficiently characterized. This study evaluates whether concurrent RT and anti-CD38 mAbs increase treatment-related toxicity. Material/Methods: We retrospectively analyzed MM patients treated at a single institution between May 2016 and February 2025. Among 180 patients receiving anti-CD38 therapy, 92 underwent RT (209 courses) to a myeloma site, and 45 (53 courses) received both treatments concomitantly. Toxicities were assessed using CTCAE v5.0 criteria. Primary endpoints included grade 3 acute hematologic toxicity. Results: RT was primarily administered for bone pain and spinal cord compression, using standard fractionation regimens (20 Gy in 5 fractions or 8 Gy single fraction). Only one grade 3 toxicity (sepsis) was observed in the cohort receiving concurrent Anti-CD38 and RT. The most frequent acute toxicity was fatigue (42 events; 15.05%). No significant increase in toxicity was observed in patients receiving RT with anti-CD38 therapy compared to those receiving mAbs alone. Conclusion: Concurrent administration of RT and CD38-directed monoclonal antibodies appears safe and does not significantly increase treatment-related toxicity. These findings support the continued use of RT for symptomatic management in MM without interrupting systemic therapy. Prospective studies are warranted to optimize RT timing and dosing and to develop predictive tools for individualized risk stratification. Keywords: Daratumumab, radiotherapy, safety
Figure 1. PRISMA flow diagram of study selection. Adapted from reference [6]. Conclusion: This systematic review demonstrates that ULD-RT (4 Gy/2 fx) achieves excellent local control with minimal toxicity and represents a cost-efficient, patient-friendly strategy for indolent OAL. Its favourable safety profile supports adoption as a first-line de-escalation approach, particularly for elderly or frail patients. Future multicentre, ophthalmology-led prospective trials with ≥ 5-year follow-up and standardized toxicity assessment are warranted to confirm long-term durability and optimize patient selection. References: 1. Tsang RW et al., J Clin Oncol 2003; 2. Goda JS et al., Int J Radiat Oncol Biol Phys 2011.3. Pinnix CC et al., JAMA Oncol 2024;4. Chelius M et al., Hematol Oncol 2021;5. Baron J et al., Front Oncol 2021;6. Gruji ć M et al., Cancers 2025; 17:2845 Keywords: systematic review, ULD-RT, ocular adnexal lymphoma
Made with FlippingBook - Share PDF online