Three venture-backed medical device firms raised more than $400 million through IPOs last quarter, Red Herring reports. Topping the list of money makers was Sunnyvale, CA-based Accuray, maker of the CyberKnife Robotic Radiosurgery System for treating tumors throughout the body with minimal damage to the surrounding tissue. The company’s February 8 debut included underwriters JP Morgan, UBS, Piper Jaffray & Co., and Jefferies & Co., according to the Associated Press. And Venture Capital Access Online notes, “Venture investors in Accuray include Marubeni Corporation and several undisclosed funds.” The offering, which raised some $288 million, culminated in a recent $1.2 billion market cap for the company. Meanwhile, stent maker Xtent (see "Xtent Forges Ahead" below) raised $75 million in a February 1 offering. Shares opened at $16.15, but recently traded at $11.06, according to MarketWatch. Xtent received funding from lead VC investor Morgenthaler Ventures. Other firms with a stake in the company include Advanced Technology Ventures, Split Rock Partners, and Latterell Venture Partners. Finally, SenoRx on March 29 priced its 5.5 million share IPO at $8 a share, yielding $44 million. Major stakeholders in the Aliso Viejo, CA, maker of breast cancer diagnostic treatment devices include MPM Capital, Mayfield Fund, De Novo Ventures and Domain Associates. Shares of SenoRx closed at $8.39 on Wednesday.