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Long-term Outcomes and Patterns of Failure in Orbital Lymphoma Treated With Primary Radiation Therapy
Volume 87 Number 2S Supplement 2013 Purpose/Objective(s): To assess the prognostic value of 18F-FDG PET SUVmax in adult Hodgkin lymphoma (HL) patients. Materials/Methods: Twenty-seven adult HL patients with pre-treatment 18 F-FDG PET/CT images were included retrospectively. Female/male ratio was 9 (33%)/18 (67%). Median age was 35 (19-63). Pathologic subgroups were NLP: 1, NS: 12, LR: 2, MC: 9, Classical: 3. Clinical stages (Ann Arbor Staging System) were IA: 4, IB: 1, IIA: 11, IIB: 4, IIIB: 2, IVA: 2, IVB: 3. Two patients had extra-nodal involvement. All patients received chemotherapy (3-8 cycles ABVD) and/or radiation therapy (20-36 Gy). The ability of SUVmax to predict prognosis was analyzed by a Receiver Operating Characteristics (ROC) curve analysis. While evaluating the area under the curve, a 5% type-1 error level was accepted a statistically significant predictive value of the test variables. The relation between SUVmax and development of recurrence was analyzed using Fisher’s exact test. The disease free survival (DFS) and overall survival (OS) were calculated with the Kaplan-Meier survival estimates. A separate long rank test was used to identify the independent effect of SUVmax on DFS and OS. Results: Median follow-up time was 20 months (6-46 months). Twenty-six patients were alive at last follow-up. Area under the ROC curve was 0.549, and the best cut-off SUVmax to predict prognosis was 9. Recurrence rate was significantly higher in patients with pre-treatment SUVmax9 compared to SUVmax <9 (3/18 vs 1/9, p Z 0.001). Median survival was 38.642.96 months and three-year disease free survival was 78.3% for all patients. There was no difference of OS or DFS between patients with SUVmax9 and SUVmax <9. Conclusions: Pre-treatment SUVmax may predict recurrence in adult HL patients. 18F-FDG PET/CT uptake before the treatment may be a valuable tool to evaluate prognosis in HL patients. Patients with a higher FDG uptake may be considered at increased risk of failure and may benefit from more aggressive treatment approaches. Author Disclosure: M. Adli: None. D. Caglayan: None. M. Koc: None. S. Zincirkeser: None. H.M. Turk: None.
2918 Prognostic Value of Angiogenic and Invasion Markers in Hodgkin Lymphoma F. Mestre,1 A. Gutierrez,2 R. Ramos,3 J. Martinez,2 and J. Pardo1; 1 University Hospital Son Espases- Radiotherapy, Palma, Spain, 2Hospital Universitario Son Espases- Department of Hematology, Palma, Spain, 3 Hospital Universitario Son Espases- Department of Pathology, Palma, Spain Purpose/Objective(s): Microenvironment has and important role in sustaining the malignant cells by providing survival signals and promoting angiogenesis and invasion. Vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), metalloproteinase-2 (MM2) and laminin are involved in angiogenesis, growth and metastatic invasion potential of malignancies. Numerous studies have demonstrated up-regulation of this protein at both mRNA and protein level in various tumors and a correlation with advanced stage and prognosis has been demonstrated in several solid tumors and hematologic malignancies such as multiple myeloma or nonHodgkin lymphomas. There is evidence that also the neoplastic HodgkinReed-Stenberg cells express VEGF and that VEGF expression both in macrophages and the extracellular matrix might facilitate tumor progression. In this work we want to analyze the role of these markers in the prognosis of Hodgkin Lymphoma. Materials/Methods: We retrospectively examined their immunohistochemical expression using a tissue array in a series of 90 cases of Hodgkin disease uniformly treated with the standard ABVD regimen (3-6 cycles, in function of clinical prognostic factors) þ/ radiation therapy (in function of clinical protocols). Median age was 30 years (14-71). Prognostic factors were as follows: 35% Ann Arbor stage IIIIV, 23% adjusted-international prognostic index >1 and 11% Hasenclever > 3. Median follow-up was 90 months. Results: Relapses were significantly higher in patients with strong VEGF staining (50% vs 19%; pZ0.04) with a significant worst progression-free survival (60% vs 84%; p Z 0.01). COX-2, MM2 and laminin showed a non-significant trend towards a lower relapse rate and PFS.
Poster Viewing Abstracts S553 Conclusions: The presence of VEGF strong staining in Hodgkin-ReedStenberg cells or reactive macrophages and the extracellular matrix might facilitate tumor progression as it was related to a shorter PFS. The trend towards a worst prognosis in higher COX-2, MM2 and laminin staining warrants further investigation of their role in the prognosis of patients with Hodgkin lymphoma. Author Disclosure: F. Mestre: None. A. Gutierrez: None. R. Ramos: None. J. Martinez: None. J. Pardo: None.
2919 The Efficacy of CHOP Regimen-Based Concurrent Chemoradiation Therapy in Patients With Nasal Extranodal Natural Killer/T-Cell Lymphoma: A Comparison Among Treatment Modalities J. Cao, S.M. Lan, N. Zhang, X.Z. Gao, H.X. Jin, G.P. Wang, and Y.P. Li; Department of Radiation Oncology, The Cancer Hospital of Shanxi Province, Taiyuan, China Purpose/Objective(s): To evaluate the efficacy of concurrent chemoradiation therapy (CCRT) with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) regimen for nasal natural killer (NK)/T-cell lymphoma (nasal ENKL) in early stages. Materials/Methods: Ninety-nine patients with stage IE or IIE disease were retrieved between 1995 and 2010, and were followed to the end of February 2012. According to treatment modalities, patients were grouped into A (chemotherapy alone; CT alone), B (sequential combined treatment) and C (concurrent chemoradiation therapy, CCRT). There were 34, 43 and 17 patients in A, B and C group, respectively. In the group B, 11 patients were treated with RT followed by CT (RT+CT), and 32 patients were treated with CT followed by RT (CT+RT). For the frontline regimens of CT (n Z 94), 77 patients were administrated 1 to 6 cycles of CHOP (or CHOP like) regimen (A:21, B:39, C:17). Other patients accepted BACOP (bleomycin, adriamycin, cyclophosphamide, oncovin and prednisone, n Z 15) (A:11, B:2, C:0) and CAV (cyclophosphamide, doxorubicin and vincristine, n Z 10) (A:2,B:2,C:0). Results: Ninety four patients were enrolled. Efficacy evaluations of both initial and overall treatment were available in 88 patients. The CR rate of initial treatment were 23/60 (38.3%), 6/11 (54.5%) and 13/17 (76.5%) for CT, radiation therapy (RT) and CCRT, respectively. At the end of treatment, among the patients with efficacy evaluations (n Z 88), CR were attained in 18/30 (60.0%), 30/43 (69.8%) and 13/17 (76.5%) patients in group A, B and C, respectively. The percentage of patients with an ECOG performance status of 0-1 was 67.6% (23/34), 86.0% (37/43) and 88.2% (15/17) in group A, B and C, respectively. In Cox regression, the ECOG performance status and the new staging system were both significant for overall survival and progression-free survival. Conclusions: Compared to chemotherapy alone and sequential combined treatment, nasal ENKL patients benefit the most from CHOP based concurrent chemoradiation therapy. Author Disclosure: J. Cao: None. S.M. Lan: None. N. Zhang: None. X.Z. Gao: None. H.X. Jin: None. G.P. Wang: None. Y.P. Li: None.
2920 Long-term Outcomes and Patterns of Failure in Orbital Lymphoma Treated With Primary Radiation Therapy R.R. Parikh,1 B. Moskowitz,2 E. Maher,2 D. Della Rocca,2 R. Della Rocca,2 B. Culliney,3 I. Shapira,3 M. Grossbard,3 L.B. Harrison,1 and K. Hu1; 1Department of Radiation Oncology, Continuum Cancer Centers of New York, Beth Israel Medical Center & St. Luke’s-Roosevelt Hospital, New York, NY, 2Department of Ophthalmology, New York Eye & Ear Infirmary, New York, NY, 3Department of Hematology-Oncology, Continuum Cancer Centers of New York, Beth Israel Medical Center & St. Luke’s-Roosevelt Hospital, New York, NY Purpose/Objective(s): Orbital lymphomas (OL) have generally been believed to follow a relatively indolent course and show a tendency to remain localized within their original site for a long period of time. Therefore, there has been no consensus regarding the initial management of primary orbital lymphoma thus far; radiation therapy has been generally
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considered the most effective treatment for localized disease. The purpose of this study was to evaluate the long-term treatment outcome and patterns of failure in patients treated with primary radiation therapy for OL. Materials/Methods: Seventy-nine patients (28 male and 51 female) diagnosed with Stage IE OL between 1995 and 2012 at CCCNY were included. The median age was 59-years old (range, 21-89). The majority had mucosaassociated lymphoid tissue (59 patients, 75%) and 20 patients (25%) were of follicular lymphoma subtype. The median radiation dose administered was 30.6 Gy. Survival data were calculated using the Kaplan-Meier method. Results: The median follow-up duration was 49.7 months. Major tumor sites were conjunctiva in 23 (29%), orbit in 37 (47%), and lacrimal gland in 19 (24%) patients. Forty-two patients had left-sided disease, and 31 patients had right-sided disease. Bilateral disease was found in 6 patients. There were no local recurrences, 1 contralateral orbital recurrence, 2 regional recurrences, and 2 distant recurrences e all outside of the treatment fields. Two patients received chemotherapy as salvage treatment. The 5- and 10-year local relapse-free survival (LRFS) rates were 100% and 100%, respectively. The 5- and 10-year contralateral orbit recurrence-free survival (CORFS) rates were 98.4% and 98.4%, respectively. The 5- and 10-year regional recurrence-free survival (RRFS) rates were 97.2% and 97.2%, respectively. The 5- and 10-year distant metastasis-free survival (DMFS) rates were 98.2% and 94.2%, respectively. The 5- and 10-year overall survival (OS) rates were 98.2% and 98.2%, respectively. Conclusions: Based on long-term observation, definitive radiation therapy to a dose of 30 Gy for OL was shown to be highly effective and safe for local control and overall survival for indolent OL. To our knowledge, this study represents one of the largest single institution studies using primary radiation therapy for Stage IE OL. Our results in disease progression revealed important aspects for future strategies in the management of OL. Author Disclosure: R.R. Parikh: None. B. Moskowitz: None. E. Maher: None. D. Della Rocca: None. R. Della Rocca: None. B. Culliney: None. I. Shapira: None. M. Grossbard: None. L.B. Harrison: None. K. Hu: None.
(objective or subjective) has been seen; in fact, improvement was seen in 3 patients. All patients tolerated the regimen well, with the typical transient decline and recovery of blood counts seen with RIT. Conclusions: Adjuvant low-dose WBRT and RIT following CNS-directed chemotherapy appears to be safe in this small sample. Complete responses were seen in all patients, and this appears to be durable compared to standard PCNSL salvage therapies. No neurocognitive deficits were seen following this novel radiation therapy regimen. Prospective studies are needed to confirm these preliminary findings. Author Disclosure: M.B. Tomblyn: F. Honoraria; Spectrum Pharmaceuticals. J. Freilich: None.
2921 Combining Low-Dose Whole Brain Radiation With Radioimmunotherapy for Primary Central Nervous System Lymphoma M.B. Tomblyn and J. Freilich; H. Lee Moffitt Cancer Center, Tampa, FL Purpose/Objective(s): Primary central nervous system lymphoma (PCNSL) is an aggressive B-cell disorder that initially responds well to therapy, but a majority of patients relapse within 2 years. High-dose whole brain radiation therapy (WBRT) was once the primary treatment, but eventual relapses and late neurocognitive sequelae were frequently observed. The addition of CNS-directed chemotherapy to WBRT improved duration of response, with a concomitant increase in neurocognitive problems. More recently, medical oncologists have attempted to avoid radiation altogether, with similar clinical responses as seen with WBRT alone. The addition of rituximab has yielded little improvement due to the poor efficiency (<1%) of the antibody to cross the blood-brain barrier (BBB). WBRT has been shown to temporarily disrupt the BBB permeability to macromolecules for several hours. We hypothesized that adjuvant low-dose WBRT followed by anti-CD20-directed radioimmunotherapy (RIT) may allow for specific dose escalation to areas of tumor cells while avoiding extra dose to uninvolved areas of the brain, decreasing the chance for significant neurocognitive deficits. Materials/Methods: Four patients (71F, 69M, 48F, 53M) with PCNSL (3 relapsed, 1 newly diagnosed) were treated with low-dose (18 Gy in 10 fractions) WBRT, with 90Y ibritumomab tiuxetan RIT given immediately after the final WBRT fraction. None of the patients had previously received radiation therapy. Median RIT dose was 24.5 (21.8-32) mCi. All patients were restaged with contrast-enhanced MRI of the brain at 3 months, and every 3 months following. At baseline and at each follow-up visit, neurocognition was tested and family members were asked about subjective changes. Results: All four patients obtained a complete response to chemotherapy + low-dose WBRT + RIT. After a median follow-up of 17.5 (12-20) months, no relapses have been observed. No decline in neurocognitive function
2922 Dosimetric Evaluation and Treatment Outcome of Intensity Modulated Radiation Therapy Following Doxorubicin-Based Chemotherapy for Primary Mediastinal Large B-Cell Lymphoma X. Li-ming, L. Ye-Xiong, F. Hui, J. Jing, W. Wei-Hu, W. Shu-Lian, L. YuePing, S. Yong-Wen, L. Qing-Feng, and C. Bo; Chinese Academy of Medical Sciences, Beijing, China Purpose/Objective(s): The value of intensity-modulated radiation therapy (IMRT) following 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. Materials/Methods: Forty-one PMBCL patients underwent mediastinal IMRT following doxorubicin-based chemotherapy (38 stage I-II patients, three stage III-IV patients). Most patients presented with bulky mediastinal disease (65.9%) and local invasion (82.9%). 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. Median mean lung dose and percentage lung volume receiving 20 Gy (V20) were 16.3 Gy and 30.6%. Five-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 following doxorubicin-based chemotherapy can be safely and efficiently delivered, and provides favorable outcomes in PMBCL patients with a large target volume and high-risk features. Author Disclosure: X. Li-ming: None. L. Ye-Xiong: None. F. Hui: None. J. Jing: None. W. Wei-Hu: None. W. Shu-Lian: None. L. Yue-Ping: None. S. Yong-Wen: None. L. Qing-Feng: None. C. Bo: None.
2923 Immunophenotypic Analysis and Clinical Heterogeneity in Patients With Extranodal Nasal-Type NK/T-Cell Lymphoma of the Upper Aerodigestive Tract Q. Liu,1 Y. Li,1 J. Jin,1 W. Wang,1 S. Wang,1 Y. Liu,1 H. Fang,1 H. Ren,1 W. Huang,2 and N. Lu2; 1Department of Radiation Oncology Cancer Hospital and Institute Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 2Department of Pathology Oncology Cancer Hospital and Institute Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China Purpose/Objective(s): Clinicopathologic and prognostic heterogeneity in extranodal nasal-type NK/T-cell lymphoma of the upper aerodigestive tract (UADT-NKTCL) have not been clearly defined. This study aims to determine the clinical and immunophenotypic differences between nasal UADT-NKTCL and extranasal UADT-NKTCL. Materials/Methods: A total of 231 patients with nasal (n Z 181) and extranasal UADT-NKTCL (n Z 50) were compared. Results: Compared with patients with nasal UADT-NKTCL, patients with extranasal UADT-NKTCL were more likely to have adverse clinical features including advanced stage disease, regional lymph node involvement, B symptoms and poor performance status. Furthermore, patients with
2918 Prognostic Value of Angiogenic and Invasion Markers in Hodgkin Lymphoma F. Mestre,1 A. Gutierrez,2 R. Ramos,3 J. Martinez,2 and J. Pardo1; 1 University Hospital Son Espases- Radiotherapy, Palma, Spain, 2Hospital Universitario Son Espases- Department of Hematology, Palma, Spain, 3 Hospital Universitario Son Espases- Department of Pathology, Palma, Spain Purpose/Objective(s): Microenvironment has and important role in sustaining the malignant cells by providing survival signals and promoting angiogenesis and invasion. Vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), metalloproteinase-2 (MM2) and laminin are involved in angiogenesis, growth and metastatic invasion potential of malignancies. Numerous studies have demonstrated up-regulation of this protein at both mRNA and protein level in various tumors and a correlation with advanced stage and prognosis has been demonstrated in several solid tumors and hematologic malignancies such as multiple myeloma or nonHodgkin lymphomas. There is evidence that also the neoplastic HodgkinReed-Stenberg cells express VEGF and that VEGF expression both in macrophages and the extracellular matrix might facilitate tumor progression. In this work we want to analyze the role of these markers in the prognosis of Hodgkin Lymphoma. Materials/Methods: We retrospectively examined their immunohistochemical expression using a tissue array in a series of 90 cases of Hodgkin disease uniformly treated with the standard ABVD regimen (3-6 cycles, in function of clinical prognostic factors) þ/ radiation therapy (in function of clinical protocols). Median age was 30 years (14-71). Prognostic factors were as follows: 35% Ann Arbor stage IIIIV, 23% adjusted-international prognostic index >1 and 11% Hasenclever > 3. Median follow-up was 90 months. Results: Relapses were significantly higher in patients with strong VEGF staining (50% vs 19%; pZ0.04) with a significant worst progression-free survival (60% vs 84%; p Z 0.01). COX-2, MM2 and laminin showed a non-significant trend towards a lower relapse rate and PFS.
Poster Viewing Abstracts S553 Conclusions: The presence of VEGF strong staining in Hodgkin-ReedStenberg cells or reactive macrophages and the extracellular matrix might facilitate tumor progression as it was related to a shorter PFS. The trend towards a worst prognosis in higher COX-2, MM2 and laminin staining warrants further investigation of their role in the prognosis of patients with Hodgkin lymphoma. Author Disclosure: F. Mestre: None. A. Gutierrez: None. R. Ramos: None. J. Martinez: None. J. Pardo: None.
2919 The Efficacy of CHOP Regimen-Based Concurrent Chemoradiation Therapy in Patients With Nasal Extranodal Natural Killer/T-Cell Lymphoma: A Comparison Among Treatment Modalities J. Cao, S.M. Lan, N. Zhang, X.Z. Gao, H.X. Jin, G.P. Wang, and Y.P. Li; Department of Radiation Oncology, The Cancer Hospital of Shanxi Province, Taiyuan, China Purpose/Objective(s): To evaluate the efficacy of concurrent chemoradiation therapy (CCRT) with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) regimen for nasal natural killer (NK)/T-cell lymphoma (nasal ENKL) in early stages. Materials/Methods: Ninety-nine patients with stage IE or IIE disease were retrieved between 1995 and 2010, and were followed to the end of February 2012. According to treatment modalities, patients were grouped into A (chemotherapy alone; CT alone), B (sequential combined treatment) and C (concurrent chemoradiation therapy, CCRT). There were 34, 43 and 17 patients in A, B and C group, respectively. In the group B, 11 patients were treated with RT followed by CT (RT+CT), and 32 patients were treated with CT followed by RT (CT+RT). For the frontline regimens of CT (n Z 94), 77 patients were administrated 1 to 6 cycles of CHOP (or CHOP like) regimen (A:21, B:39, C:17). Other patients accepted BACOP (bleomycin, adriamycin, cyclophosphamide, oncovin and prednisone, n Z 15) (A:11, B:2, C:0) and CAV (cyclophosphamide, doxorubicin and vincristine, n Z 10) (A:2,B:2,C:0). Results: Ninety four patients were enrolled. Efficacy evaluations of both initial and overall treatment were available in 88 patients. The CR rate of initial treatment were 23/60 (38.3%), 6/11 (54.5%) and 13/17 (76.5%) for CT, radiation therapy (RT) and CCRT, respectively. At the end of treatment, among the patients with efficacy evaluations (n Z 88), CR were attained in 18/30 (60.0%), 30/43 (69.8%) and 13/17 (76.5%) patients in group A, B and C, respectively. The percentage of patients with an ECOG performance status of 0-1 was 67.6% (23/34), 86.0% (37/43) and 88.2% (15/17) in group A, B and C, respectively. In Cox regression, the ECOG performance status and the new staging system were both significant for overall survival and progression-free survival. Conclusions: Compared to chemotherapy alone and sequential combined treatment, nasal ENKL patients benefit the most from CHOP based concurrent chemoradiation therapy. Author Disclosure: J. Cao: None. S.M. Lan: None. N. Zhang: None. X.Z. Gao: None. H.X. Jin: None. G.P. Wang: None. Y.P. Li: None.
2920 Long-term Outcomes and Patterns of Failure in Orbital Lymphoma Treated With Primary Radiation Therapy R.R. Parikh,1 B. Moskowitz,2 E. Maher,2 D. Della Rocca,2 R. Della Rocca,2 B. Culliney,3 I. Shapira,3 M. Grossbard,3 L.B. Harrison,1 and K. Hu1; 1Department of Radiation Oncology, Continuum Cancer Centers of New York, Beth Israel Medical Center & St. Luke’s-Roosevelt Hospital, New York, NY, 2Department of Ophthalmology, New York Eye & Ear Infirmary, New York, NY, 3Department of Hematology-Oncology, Continuum Cancer Centers of New York, Beth Israel Medical Center & St. Luke’s-Roosevelt Hospital, New York, NY Purpose/Objective(s): Orbital lymphomas (OL) have generally been believed to follow a relatively indolent course and show a tendency to remain localized within their original site for a long period of time. Therefore, there has been no consensus regarding the initial management of primary orbital lymphoma thus far; radiation therapy has been generally
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International Journal of Radiation Oncology Biology Physics
considered the most effective treatment for localized disease. The purpose of this study was to evaluate the long-term treatment outcome and patterns of failure in patients treated with primary radiation therapy for OL. Materials/Methods: Seventy-nine patients (28 male and 51 female) diagnosed with Stage IE OL between 1995 and 2012 at CCCNY were included. The median age was 59-years old (range, 21-89). The majority had mucosaassociated lymphoid tissue (59 patients, 75%) and 20 patients (25%) were of follicular lymphoma subtype. The median radiation dose administered was 30.6 Gy. Survival data were calculated using the Kaplan-Meier method. Results: The median follow-up duration was 49.7 months. Major tumor sites were conjunctiva in 23 (29%), orbit in 37 (47%), and lacrimal gland in 19 (24%) patients. Forty-two patients had left-sided disease, and 31 patients had right-sided disease. Bilateral disease was found in 6 patients. There were no local recurrences, 1 contralateral orbital recurrence, 2 regional recurrences, and 2 distant recurrences e all outside of the treatment fields. Two patients received chemotherapy as salvage treatment. The 5- and 10-year local relapse-free survival (LRFS) rates were 100% and 100%, respectively. The 5- and 10-year contralateral orbit recurrence-free survival (CORFS) rates were 98.4% and 98.4%, respectively. The 5- and 10-year regional recurrence-free survival (RRFS) rates were 97.2% and 97.2%, respectively. The 5- and 10-year distant metastasis-free survival (DMFS) rates were 98.2% and 94.2%, respectively. The 5- and 10-year overall survival (OS) rates were 98.2% and 98.2%, respectively. Conclusions: Based on long-term observation, definitive radiation therapy to a dose of 30 Gy for OL was shown to be highly effective and safe for local control and overall survival for indolent OL. To our knowledge, this study represents one of the largest single institution studies using primary radiation therapy for Stage IE OL. Our results in disease progression revealed important aspects for future strategies in the management of OL. Author Disclosure: R.R. Parikh: None. B. Moskowitz: None. E. Maher: None. D. Della Rocca: None. R. Della Rocca: None. B. Culliney: None. I. Shapira: None. M. Grossbard: None. L.B. Harrison: None. K. Hu: None.
(objective or subjective) has been seen; in fact, improvement was seen in 3 patients. All patients tolerated the regimen well, with the typical transient decline and recovery of blood counts seen with RIT. Conclusions: Adjuvant low-dose WBRT and RIT following CNS-directed chemotherapy appears to be safe in this small sample. Complete responses were seen in all patients, and this appears to be durable compared to standard PCNSL salvage therapies. No neurocognitive deficits were seen following this novel radiation therapy regimen. Prospective studies are needed to confirm these preliminary findings. Author Disclosure: M.B. Tomblyn: F. Honoraria; Spectrum Pharmaceuticals. J. Freilich: None.
2921 Combining Low-Dose Whole Brain Radiation With Radioimmunotherapy for Primary Central Nervous System Lymphoma M.B. Tomblyn and J. Freilich; H. Lee Moffitt Cancer Center, Tampa, FL Purpose/Objective(s): Primary central nervous system lymphoma (PCNSL) is an aggressive B-cell disorder that initially responds well to therapy, but a majority of patients relapse within 2 years. High-dose whole brain radiation therapy (WBRT) was once the primary treatment, but eventual relapses and late neurocognitive sequelae were frequently observed. The addition of CNS-directed chemotherapy to WBRT improved duration of response, with a concomitant increase in neurocognitive problems. More recently, medical oncologists have attempted to avoid radiation altogether, with similar clinical responses as seen with WBRT alone. The addition of rituximab has yielded little improvement due to the poor efficiency (<1%) of the antibody to cross the blood-brain barrier (BBB). WBRT has been shown to temporarily disrupt the BBB permeability to macromolecules for several hours. We hypothesized that adjuvant low-dose WBRT followed by anti-CD20-directed radioimmunotherapy (RIT) may allow for specific dose escalation to areas of tumor cells while avoiding extra dose to uninvolved areas of the brain, decreasing the chance for significant neurocognitive deficits. Materials/Methods: Four patients (71F, 69M, 48F, 53M) with PCNSL (3 relapsed, 1 newly diagnosed) were treated with low-dose (18 Gy in 10 fractions) WBRT, with 90Y ibritumomab tiuxetan RIT given immediately after the final WBRT fraction. None of the patients had previously received radiation therapy. Median RIT dose was 24.5 (21.8-32) mCi. All patients were restaged with contrast-enhanced MRI of the brain at 3 months, and every 3 months following. At baseline and at each follow-up visit, neurocognition was tested and family members were asked about subjective changes. Results: All four patients obtained a complete response to chemotherapy + low-dose WBRT + RIT. After a median follow-up of 17.5 (12-20) months, no relapses have been observed. No decline in neurocognitive function
2922 Dosimetric Evaluation and Treatment Outcome of Intensity Modulated Radiation Therapy Following Doxorubicin-Based Chemotherapy for Primary Mediastinal Large B-Cell Lymphoma X. Li-ming, L. Ye-Xiong, F. Hui, J. Jing, W. Wei-Hu, W. Shu-Lian, L. YuePing, S. Yong-Wen, L. Qing-Feng, and C. Bo; Chinese Academy of Medical Sciences, Beijing, China Purpose/Objective(s): The value of intensity-modulated radiation therapy (IMRT) following 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. Materials/Methods: Forty-one PMBCL patients underwent mediastinal IMRT following doxorubicin-based chemotherapy (38 stage I-II patients, three stage III-IV patients). Most patients presented with bulky mediastinal disease (65.9%) and local invasion (82.9%). 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. Median mean lung dose and percentage lung volume receiving 20 Gy (V20) were 16.3 Gy and 30.6%. Five-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 following doxorubicin-based chemotherapy can be safely and efficiently delivered, and provides favorable outcomes in PMBCL patients with a large target volume and high-risk features. Author Disclosure: X. Li-ming: None. L. Ye-Xiong: None. F. Hui: None. J. Jing: None. W. Wei-Hu: None. W. Shu-Lian: None. L. Yue-Ping: None. S. Yong-Wen: None. L. Qing-Feng: None. C. Bo: None.
2923 Immunophenotypic Analysis and Clinical Heterogeneity in Patients With Extranodal Nasal-Type NK/T-Cell Lymphoma of the Upper Aerodigestive Tract Q. Liu,1 Y. Li,1 J. Jin,1 W. Wang,1 S. Wang,1 Y. Liu,1 H. Fang,1 H. Ren,1 W. Huang,2 and N. Lu2; 1Department of Radiation Oncology Cancer Hospital and Institute Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 2Department of Pathology Oncology Cancer Hospital and Institute Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China Purpose/Objective(s): Clinicopathologic and prognostic heterogeneity in extranodal nasal-type NK/T-cell lymphoma of the upper aerodigestive tract (UADT-NKTCL) have not been clearly defined. This study aims to determine the clinical and immunophenotypic differences between nasal UADT-NKTCL and extranasal UADT-NKTCL. Materials/Methods: A total of 231 patients with nasal (n Z 181) and extranasal UADT-NKTCL (n Z 50) were compared. Results: Compared with patients with nasal UADT-NKTCL, patients with extranasal UADT-NKTCL were more likely to have adverse clinical features including advanced stage disease, regional lymph node involvement, B symptoms and poor performance status. Furthermore, patients with