Shares of Varian Medical Systems (NYSE:VAR) and Elekta AB (STO:EKTA B) gained yesterday after news broke that rival Siemens (NYSE:SI) plans to scale back its radiation therapy business.

VAR shares closed at $60.60 yesterday, up 6.2 percent on the day, passing a high-water mark of $61.15 along the way.

Sign up to get our free newsletters delivered right to your inbox

The surge came in response to the revelation that Siemens plans to "selectively exit" radiation therapy, disclosed by JP Morgan Chase & Co. analyst Tycho Peterson, according to Bloomberg.

"Siemens has been losing share in this market for years to both Varian and Elekta, so the news does not come as a complete surprise," Peterson wrote in a note to investors. "The exit should accelerate additional share shift and could provide upside to Street estimates."

Elekta shares also climbed yesterday, closing at SEK 284 (about $41.93), up 4.4 percent on the day.