They found that increasing attention has been paid to rectal toxicity as a complication of radiotherapy, particularly following the introduction of dose escalation for prostate cancer treatment.

"One third of men over 65 who don't have surgery or radiation get this therapy," she said. "Yet its effects have never been studied in a controlled trial."

Three-dimensional conformal radiotherapy is a mostly-used external radiotherapy for some tumors, e. g. prostate carcinoma, head and neck cancer, breast cancer and lung cancer ect.