Sessions or any alternatives in webAPI

I have a business logic which has lot of DB fetch operations and a bit complex business logic. Data fetched is rarely changed within the session of user.

• Many Fetch opertaions(data fetched is rarely changed within the session of user).
• For each and every action on the form(button click/ value change in Textbox etc...) we need to run the business logic to check if it's valid change.

Currently we are using Asp.net Forms Application and these business logic is in InSessionScope(). Currently we are working on migrating to Restful API(WebAPI).

• Can we use sessions(InSessionScope()) in RESTFul?
• If not in sessions how to avoid more database calls and use the same object on subsequent calls and increase performance?