Dosimetric Evaluation and Treatment Outcome of Intensity Modulated Radiation Therapy After Doxorubicin-Based Chemotherapy for Primary Mediastinal Large B-Cell Lymphoma.
Dec 2012
Xu LM, Li YX, Fang H, Jin J, Wang WH, Wang SL, Liu YP, Song YW, Liu QF, Chen B, Qi SN, Ren H, Dai JR.
Source
Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, P. R. China.
Abstract
PURPOSE:
The value of intensity-modulated radiation therapy (IMRT) after doxorubicin-based chemotherapy in primary mediastinal large B-cell lymphoma (PMBCL) is unknown. We assessed the dosimetric parameters, treatment outcomes, and toxicity of IMRT in PMBCL.
METHODS AND MATERIALS:
Forty-one PMBCL patients underwent mediastinal IMRT after doxorubicin-based chemotherapy. Thirty-eight patients had stage I-II disease, and 3 patients had stage III-IV disease. Most patients presented with bulky mediastinal disease (65.9%) and local invasion (82.9%). The dose-volume histograms of the target volume and critical normal structures were evaluated.
RESULTS:
The average planning target volume (PTV) mean dose was 39 Gy. Only 0.5% and 1.4% of the PTV received <90% and <95% of the prescribed dose, respectively, indicating excellent target coverage. The median mean lung dose and percentage lung volume receiving 20 Gy (V20) were 16.3 Gy and 30.6%. The 5-year overall survival (OS) and local control (LC) were 95.1% and 89.8%. After chemotherapy, consolidation radiation therapy in patients with complete/partial response resulted in significantly better survival than salvage radiation therapy in patients with stable/progressive disease (3-year OS 100% vs 75%; 3-year LC 96.6% vs 62.5%). No grade 4 or 5 acute or late toxicities occurred.
CONCLUSIONS:
Mediastinal IMRT after doxorubicin-based chemotherapy can be safely and efficiently delivered, and it provides favorable outcomes in PMBCL patients with a large target volume and high-risk features.
