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.

Elsevier - Radiation Oncology

Prognostic significance of rituximab and radiotherapy for patients with primary mediastinal large B-cell lymphoma receiving doxorubicin-containing chemotherapy.

Nov 2012

Xu LM, Fang H, Wang WH, Jin J, Wang SL, Liu YP, Song YW, Ren H, Zhou LQ, Li YX.

Abstract

The aim of this study was to evaluate the prognostic importance of rituximab and radiotherapy in patients with primary mediastinal large B-cell lymphoma (PMBCL) receiving doxorubicin-containing chemotherapy. Seventy-nine patients with PMBCL received CHOP chemotherapy with (n = 39) or without rituximab (n = 40), and 60 patients received additional radiotherapy. Patients treated with R-CHOP had significantly superior survival rates. The 5-year overall survival (OS) and progression-free (PFS) rates were 83.7% and 76.7% for R-CHOP, compared with 48.3% (P=0.011) and 44.2% (P=0.012) for CHOP, respectively. Similarly, the 5-year OS and PFS rates for early stage patients were 93.8% and 84.6% with R-CHOP, and 52.0% (P=0.002) and 46.6% (P=0.003) with CHOP, respectively. Patients treated with chemotherapy and radiotherapy had better survival and local control (LC) rates compared with chemotherapy alone. The 5-year OS, PFS and LC rates for early stage patients were 73.6%, 69.9% and 92.6% for chemotherapy and radiotherapy, and 50.8% (P = 0.076), 36.9% (P = 0.008) and 56.4% (P<0.001) for chemotherapy alone, respectively. Early stage patients treated with R-CHOP and radiotherapy had 5-year OS, PFS and LC rates of 96.4%, 85.9% and 93.1%. R-CHOP plus consolidation radiotherapy was associated with excellent survival and LC rates.

PubMed