We have retrospectively reviewed toxicities and response of a cohort of primary central nervous system lymphoma (PCNSL) patients treated with high dose parenteral methotrexate (MTX) monotherapy without whole brain radiation. From The Massachusetts General Hospital (MGH) Cancer Registry, active since 1946, we selected all immunocompetent patients with histologic and/or radiographic PCNSL diagnosed between 1980 and 2007. We identified the recipients of MTX with leucovorin rescue as sole therapy. No patient received radiation therapy (XRT). We analyzed this cohort for toxicity, response and patterns of recurrence. The cohort of 121 patients received on average 11 cycles of intravenous MTX at a median dose of 8 g/m2. Median interval between cycles was 10 days. After 3 months of therapy, the overall response rate was 85% (58% CR, 27% PR). The overall survival (OS) for the cohort was 7 years and progression-free survival (PFS) was 3.14 years. A trend toward a higher PFS was seen in patients who continued to receive MTX (3.48 years) every three months as compared to patients who ceased MTX after one year (2.86 years). Of 68 patients who achieved initial CR, there were 40 recurrences. Twenty-six of the 40 were re-induced with MTX as above; Sixty-nine percent again achieved CR. Eighty-one treatment-related toxicities occurred in 1316 MTX cycles. These toxicities included MRI white matter changes (N = 8) and lead to MTX cessation in 16 patients. High-dose MTX monotherapy of PCNSL is well-tolerated and provides PFS of >3 years and OS >7 years.

In addition to the well-characterized BRCA1 and BRCA2 hereditary breast and ovarian cancer syndromes, many other syndromes that are associated with genetic mutations predispose individuals to an increased risk of breast and gynecologic malignancies. Many mutated genes encode for tumor-suppressor products and are inherited in an autosomal dominant manner. Mutations markedly increase an individual's lifetime risk of cancers in different organ systems, depending on the associated syndrome. These syndromes include Lynch syndrome, the most common hereditary cause of endometrial cancer, and Peutz-Jeghers syndrome, which increases the risks of breast cancer, ovarian cancer, and cervical adenoma malignum. Li-Fraumeni syndrome and Cowden syndrome increase the risk of breast cancer, and Gorlin syndrome increases the risk of ovarian fibromas. With advances in genetic testing, clinicians' knowledge and awareness of the numerous additional genes associated with breast and ovarian cancers, such as ATM, CHEK2, and PALB2, are rapidly expanding. Radiologists have essential roles in patient management, which include developing optimal screening protocols for these patients and closely monitoring them for the development or recurrence of disease-specific malignancies. Radiologists' roles continue to increase and evolve as more mutations are identified and high-risk imaging screening recommendations expand to identify these patients. Understanding the epidemiologic, genetic, and pathophysiologic features and the cancers associated with these syndromes enables radiologists to appropriately contribute to patient management, ensure accurate and timely diagnosis, and make syndrome-specific imaging recommendations.© RSNA, 2020 • radiographics.rsna.org