Treatment of Primary Central Nervous System Lymphoma (PCNSL): Comparison of Whole Brain Radiation Therapy and Partial Brain Radiation Therapy

Poster Viewing Abstracts S617

Volume 84  Number 3S  Supplement 2012 Author Disclosure: X. Zhang: None. Y. Li: None. S. Wang: None. W. Wang: None. J. Jin: None. Y. Liu: None. Y. Song: None. X. Liu: None. L. Zhou: None. Z. Yu: None.

3061 Outcomes of ALK-negative Anaplastic Large Cell Lymphoma are Superior to Peripheral T-cell Lymphoma, Not Otherwise Specified: Report From a Single Chinese Institution X. Zhang, Y. Li, S. Wang, W. Wang, J. Jin, Y. Liu, Y. Song, X. Liu, L. Zhou, and Z. Yu; Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, P.R. China, Beijing, China Purpose/Objective(s): Prognosis between ALK-negative anaplastic largecell lymphoma (ALK- ALCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is controversial. The aim of this study is to determine the different clinical features and outcomes of the two entities. Materials/Methods: Thirty-four patients with ALK- ALCL and sixty patients with PTCL-NOS between 1998 and 2010 were compared. There were 18 cases of stage I, 28 cases of stage II, 28 cases of stage III and 18 cases of stage IV disease. Patients received primary chemotherapy with or without radiation therapy. Results: The major clinical features, including age, lactate dehydrogenase, microglobulin, B symptom, extranodal involvement, stage, performance status, and international prognostic index were comparable between patients with ALK- ALCL and PTCL-NOS. However, patients with PTCLNOS had a significant male predominance. The 3-year overall survival (70.1% vs 46.1%; PZ0.002) and progression-free survival (48.3% vs 33.2%; PZ0.001) were superior for ALK- ALCL compared with PTCLNOS. Conclusions: Although clinical manifestations were similar, treatment outcomes were superior for ALK- ALCL compared with PTCL-NOS. Author Disclosure: X. Zhang: None. Y. Li: None. S. Wang: None. W. Wang: None. J. Jin: None. Y. Liu: None. Y. Song: None. X. Liu: None. L. Zhou: None. Z. Yu: None.

3062 Treatment of Primary Central Nervous System Lymphoma (PCNSL): Comparison of Whole Brain Radiation Therapy and Partial Brain Radiation Therapy M. Iwabuchi,1 C. Sugie,1 H. Ogino,2 S. Ayakawa,3 F. Baba,4 and Y. Shibamoto1; 1Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan, 2Nagoya City, Nagoya, Japan, 3Japanese Red Cross Nagoya Daini Hospital, Nagoya, Japan, 4Social Insurance Chukyo hospital, Nagoya, Japan Purpose/Objective(s): High-dose methotrexate (MTX)-based chemotherapy and whole-brain radiation therapy (WBRT) is considered to be a choice of treatment to cure PCNSL patients younger than 60 years of age. However, unacceptable delayed neurotoxicity is a concern, as the improvement in treatment has increased survival rates. Elimination of WBRT is associated with a higher rate of relapse. Partial-brain irradiation (PBRT) may reduce the risk of neurotoxicity, while maintaining a high rate of tumor control. Since 2005, our group has employed partial-brain irradiation with wide margins in patients with solitary PCNSL. In this study, we analyzed results of treatment for PCNSL, with special reference to WBRT versus PBRT. Materials/Methods: Between 1993 and 2011, 74 patients (median age, 63; range, 25-90) with histologically-confirmed PCNSL were treated with radiation therapy with or without chemotherapy. Sixty patients were treated with WBRT with or without focal boost, while 14 were treated by PBRT with approximately 4-cm margins from tumor mass generally followed by focal boost. The median patient age was 62 years (range, 25-90) in the WBRT group and 66 years (range, 49-75) in the PBRT group. Multiple tumors were seen in 28 of the 60 patients (47%) of the WBRT group and in 2 of the 14 patients (14%) of the PBRT group. Median

maximum tumor diameter was 34.5 mm (range, 3-80) in the WBRT group and 38.5 mm (range, 12-60) in the PBRT group. Daily 2-Gy fractions were used in vast majority of cases. Median total dose was 50 Gy (range, 20-60) in the WBRT group and 50 Gy (range, 30.6-54) in the PBRT group. MTXbased chemotherapy was used in 15 of the 60 patients (25%) of the WBRT group and in 12 of the 14 patients (86%) of the PBRT group. Results: Response rates in WBRT and PBRT groups were 73% and 92%, respectively (P Z 0.12). The median survival time was 16 months for the WBRT group and 19 months for the PBRT group. The 3-year overall survival rate was 42% versus 41% (P Z 0.17). The 3-year CNS-recurrence rate was 48% and 53%, respectively (P Z 0.93); when only patients with a single tumor were analyzed, the rate was 52% versus 40% (P Z 0.79). The 3-year extra-CNS-recurrence rate was 20% versus 14% (P Z 0.85). In the PBRT group, the 2-year rate for out-of-field CNS recurrence was 15%. Late neurotoxicity of WBRT was encountered in a 65-year-old patient and in 4 patients under 60 years of age. Two patients over 60 years old treated with PBRT developed treatment-related late neurotoxicity, but no patient under 60 years of age treated with PBRT developed this adverse event. Conclusions: PBRT may be considered as a treatment option of solitary PCNSL. Combination with MTX-based chemotherapy may be worthy of further investigation, in place of WBRT. Author Disclosure: M. Iwabuchi: None. C. Sugie: None. H. Ogino: None. S. Ayakawa: None. F. Baba: None. Y. Shibamoto: None.

3063 Prognostic Importance of Rituximab and Radiation Therapy in Patients With Primary Mediastinal B-cell Lymphoma Receiving Doxorubicin-containing Chemotherapy L. Xu, H. Fang, S. Wang, W. Wang, J. Jin, Y. Liu, Y. Song, Q. Liu, Z. Yu, and Y. Li; Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, China Purpose/Objective(s): The prognostic importance of rituximab and radiation therapy in patients with primary mediastinal large B-cell lymphoma (PMBCL) has not been well defined. The aim of the this study was to evaluate the prognostic values of rituximab and radiation therapy in PMBCL patients receiving doxorubicin-containing chemotherapy. Methods/Materials: Between 1992 and 2010, 79 consecutive patients with previously untreated PMBCL received CHOP or CHOP-like chemotherapy with (nZ38) or without rituximab (nZ41). Sixty-one (77.2%) patients were treated with involved-field radiation therapy following chemotherapy. The median radiation dose was 45 Gy. The majority of patients presented with bulky mediastinum (68.4%), local invasion (74.7%), elevated LDH (72.2%), and early stage disease (84.8%). Results: The 5-year overall survival (OS), progression-free survival (PFS) and local control (LC) rates for all patients were 62.0%, 58.8% and 87.5%, respectively. LDH and Ann Arbor stage were significant prognostic factors. Patients treated with R-CHOP had significantly superior survivals. The 5-year OS and PFS rates were 83.2% and 76.1% for R-CHOP, compared with 49.1% and 45.3% for CHOP (PZ0.016 for OS, PZ0.020 for PFS). Similarly, the 5-year OS and PFS rates were 93.5% and 84.1% for early stage patients with R-CHOP compared with 52.8% and 47.8% for those with CHOP, respectively (PZ0.002 for OS, PZ0.005 for PFS). Patients treated with chemotherapy and radiation therapy had significantly superior survivals and LC compared with chemotherapy alone. The 5-year OS, PFS and LC rates were 69.4%, 66.3% and 93.2% for chemotherapy and radiation therapy compared with 40.9%, 33.8% and 66.2% for chemotherapy alone, respectively (PZ0.017 for OS, PZ0.003 for PFS, PZ0.002 for LC). Similar results were observed in 67 patients with early stage disease. The corresponding OS, PFS and LC rates were 73.6%, 69.9% and 92.6% for chemotherapy and radiation therapy compared with 50.8%, 36.9% and 56.4% for chemotherapy alone, respectively (PZ0.076 for OS, PZ0.008 for PFS, P<0.001 for LC). Conclusions: Integration of rituximab and radiation therapy into CHOP resulted in an excellent outcome for patients with PMBCL, and R-CHOP