Radiation combined with immune-stimulating drugs against Cancer

Radiation can't target every tumor or every cancer cell in the body. It isn't feasible to deliver radiation to each and every place tumor cells have migrated once the disease metastasizes throughout the body.
That is where a phenomenon called the "abscopal effect" comes in. Abscopal means "away from target," and is a radiation biology term that describes a fascinating phenomenon: sometimes treating a tumor with radiation in one part of the body causes the elimination and cure of a nontreated tumor at a different location. Many scientists attribute this effect to the activity of immune cells, triggered by radiation, mounting an effective attack against untreated tumors. It has also been observed in cancer patients in the clinic. In the past few years, there have been several high-profile reports of abscopal responses in patients with lung, melanoma and other cancers. These patients all received some form of cancer immunotherapy in addition to the radiation therapy.
Researchers still aren't sure exactly how to make abscopal responses happen consistently. The challenge is to figure out what exactly is responsible for the abscopal effect so that it can be reproduced reliably in more patients treated with combination therapy.
Questions remain about what the best radiation dose is to cause this effect, the optimal timing to give radiation relative to the cancer immunotherapy, what specific types of cancer are most likely to respond this way and which immunotherapy (from the ever-growing list) is the best for causing this effect in combination strategies.
The overall good news is that radiation can make tumor cells tickle T cells into action. Thus, cancer immunotherapies may help repurpose the use of one of the oldest cancer treatments in new ways.