Treatment outcomes for patients with chloroma receiving radiation therapy

Introduction: This study aims to analyse treatment outcomes, disease control and toxicity in patients with chloromas referred for radiation therapy (RT). Methods: Medical records were retrospectively reviewed for 41 patients with chloromas treated with RT at our institution. Results: Twenty-five patients were treated with palliative intent, whereas sixteen received RT as a component of curative intent therapy in addition to systemic chemotherapy with or without haematopoietic stem cell transplant (HSCT). All patients received RT for chloroma (median dose 24 Gy). Median survival was 5.4 months after RT (95% confidence interval (CI) 3.5-12.6 months), and no significant difference in overall survival was identified based on prior treatment with systemic chemotherapy alone or HSCT. Patients treated with curative intent had a median survival of 26.2 months (95% CI 6.1-48.9 months) and a Kaplan-Meier estimate of 15% overall survival at 5 years. At the end of the study follow-up period, 38 patients were dead and three patients treated with curative intent remained alive. After palliative RT, 44% of patients experienced partial relief and 48% experienced complete symptomatic improvement without significant acute toxicities. Conclusions: RT provides timely symptom palliation for patients with chloromas with minimal morbidity, but the prognosis remains poor. Longterm remission can be achieved in selected patients with salvage chemotherapy and HSCT.