Radiotherapy dose-response analysis for diffuse large B-cell lymphoma with a complete response to chemotherapy.

Abstract

OBJECTIVE:

To examine the efficacy of different radiation doses after achievement of a complete response to chemotherapy in diffuse large B-cell lymphoma (DLBCL).

METHODS:

Patients with stage I-IV DLBCL treated from 1995-2009 at Duke Cancer Institute who achieved a complete response to chemotherapy were reviewed. In-field control, event-free survival, and overall survival were calculated using the Kaplan-Meier method. Dose response was evaluated by grouping treated sites by delivered radiation dose.

RESULTS:

105 patients were treated with RT to 214 disease sites. Chemotherapy (median 6 cycles) was R-CHOP (65%), CHOP (26%), R-CNOP (2%), or other (7%). Post-chemotherapy imaging was PET/CT (88%), gallium with CT (1%), or CT only (11%). The median RT dose was 30 Gy (range, 12-40 Gy). The median radiation dose was higher for patients with stage I-II disease compared with patients with stage III-IV disease (30 versus 24.5 Gy, p < 0.001). Five-year in-field control, event-free survival, and overall survival for all patients was 94% (95% CI: 89-99%), 84% (95% CI: 77-92%), and 91% (95% CI: 85-97%), respectively. Six patients developed an in-field recurrence at 10 sites, without a clear dose response. In-field failure was higher at sites ≥ 10 cm (14% versus 4%, p = 0.06).

CONCLUSION:

In-field control was excellent with a combined modality approach when a complete response was achieved after chemotherapy without a clear radiation dose response.

• Authors: Jennifer A Dorth, Leonard R Prosnitz, Gloria Broadwater, Anne W Beaven, Chris R Kelsey
• Journal: Radiation oncology (London, England) (Radiat Oncol) Vol. 7 Pg. 100 (Jun 21 2012) ISSN: 1748-717X [Electronic] England
• PMID: 22720801 (Publication Type: Journal Article)

Topics

• Adult
• Aged
• Aged, 80 and over
• Antineoplastic Combined Chemotherapy Protocols (administration & dosage)
• Chemoradiotherapy
• Disease-Free Survival
• Dose-Response Relationship, Radiation
• Female
• Humans
• Lymphoma, Large B-Cell, Diffuse (drug therapy, mortality, radiotherapy)
• Male
• Middle Aged
• Neoplasm Staging
• Retrospective Studies
• Young Adult