Brain Tumor Social Media (#BTSM) is a patient and care partner-run, grassroots Twitter community. The Twitter account @BTSMchat hosts monthly tweet chats for the #BTSM community (the Twitter equivalent of a cancer support group) and consistently trends among the top 15 of disease-related tweet chats. A study published in 2020 revealed the hashtag was most commonly used by brain tumor patients (33.13%), along with patient advocacy organizations (7.01%), care partners (4.63%), and clinicians (3.63%) and researchers (3.37%) specializing in brain tumors and brain cancers.

The Brain Tumor Social Media hashtag—#BTSM—was introduced to the medical community in "Disease-Specific Hashtags for Online Communication About Cancer Care" published in JAMA Oncology, and later covered as a case study in maintaining a successful online health-oriented community (published in JCO Clinical Cancer Informatics). Guidelines for neuro-oncology professionals interacting with patients on social media were introduced in the journal Neuro-Oncology.

The #BTSM hashtag represents benign and malignant brain tumors. In a 2016 interview for CURE magazine, #BTSM organizer @TheLizArmy said, “There are over 120 different brain tumors… I liked the idea of an inclusive group for everyone with brain tumors where we can all share our experiences.”