Except for sporadic case reports, few articles have focused on the topic and little is known about the practice of CNS prophylaxis in PTCL worldwide. Correspondence: Dr Barbara Pro, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Box 429, Houston, TX 77030; e-mail: bpro@mdanderson.org. Advertisers, Journal of Clinical Oncology Challenging a paradigm, Non-Hodgkin’s lymphoma of the brain: Can high dose, large volume radiation therapy improve survival? DOI: 10.1200/JCO.2017.72.7602 Journal of Clinical Oncology - International Peripheral T-Cell Lymphoma Project. No comparison study has been conducted thus far. The following represents disclosure information provided by authors of this manuscript. Primary central nervous system non-Hodgkin’s lymphoma: Survival advantages with combined initial therapy? Natural history of CNS relapse in patients with aggressive non-Hodgkin’s lymphoma: a 20-year follow-up analysis of SWOG 8516 — the Southwest Oncology Group. PCNSL in immunocompetent patients is rare and represents 4% of all intracranial neoplasms and 4% to 6% of all extranodal lymphomas.1 However, in recent years, a rising incidence has been recognized, particularly in patients older than 60 years, with an incidence rate of 0.5 per 100,000 per year.2 Approximately 1,500 new patients are diagnosed each year in the United States. Relapse pattern is displayed in Table 2. World Health Organization classification of tumours of haematopoietic and lymphoid tissues, International Harmonization Project on Lymphoma. Intravenous methotrexate as central nervous system (CNS) prophylaxis is associated with a low risk of CNS recurrence in high-risk patients with diffuse large B-cell lymphoma. Elevated LDH and paranasal sinus involvement are risk factors for central nervous system involvement in patients with peripheral T-cell lymphoma. For more information about ASCO's conflict of interest policy, please refer to www.asco.org/rwc or ascopubs.org/jco/site/ifc. The role of surgery in PCNSL is generally restricted to stereotactic biopsy due to widespread and diffusely infiltrative tumor growth. Search for other works by this author on: CNS events in elderly patients with aggressive lymphoma treated with modern chemotherapy (CHOP-14) with or without rituximab: an analysis of patients treated in the RICOVER-60 trial of the German High-Grade Non-Hodgkin Lymphoma Study Group (DSHNHL). Currently, HD-MTX (> 3 g/m2) and rituximab should be part of any induction treatment. One patient with CD4+/CD56+ hematodermic neoplasm received CNS prophylaxis based only on histology. Supported by the National Institutes of Health/National Cancer Institute Cancer Center Support Grant No. Frequencies given for each histological group. Groupe d’Etudes des Lymphomes de l’Adulte. In the 560-mg trial, patients with recurrent PCNSL or ocular lymphoma were enrolled, and the first 18 patients had three complete and seven partial responses after 2 months of treatment.91 In the 840-mg trial, 20 patients with recurrent PCNSL and secondary CNS lymphoma achieved an ORR (complete and partial) of 75% (77% in PCNSL and 71% in secondary CNS lymphoma) and a median PFS of 5.4 months at a median follow-up of 255 days.92 In both trials, as well as in an additional trial combining ibrutinib with temozolomide, doxorubicin, etoposide, dexamethasone, and rituximab (DA-TEDDI-R; NCT02203526), pulmonary and cerebral aspergillosis were observed. Two of the CNS relapsed patients received prophylactic intrathecal methotrexate, and 1 received liposomal cytarabine. There was no separate pathology review performed in the study. (C) Diffusion-weighted imaging (DWI) demonstrates restricted diffusion within the tumor.