An approach combining immune-based therapies with focused radiation, including stereotactic radiation, to treat cancers is disclosed. The use of focused radiation primes the immune system in a similar manner to vaccines to augment immune-based therapies and can counteract the suppressive effects of a tumor. The combination of focused radiation and immune-based therapies, including administration of at least one immunotherapeutic agent, improves survival compared to each therapy alone and can, in some cases, lead to a durable cure. Accordingly, focused radiation can be an adjuvant for immune-based therapies for treating cancers.