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Tsavo the lion receives treatment to remove orange size tumor

Amy Smotherman Burgess / Knoxville News Sentinel via AP

Veterinary students Nicole Bayless, left, and Megan Richards, along with technician Janet Pezzi, prepare an African lion named Tsavo for cancer treatment at the University of Tennessee's Veterinary Medical Center in Knoxville, Tenn. The 11-year-old big cat is undergoing radiation treatment for a large tumor near its mouth.

Amy Smotherman Burgess / Knoxville News Sentinel via AP

Dr. James Steeil prepares an African lion named Tsavo for cancer treatment at the University of Tennessee's Veterinary Medical Center in Knoxville, Tenn. The 11-year-old big cat is undergoing radiation treatment for a large tumor near its mouth.

Amy Smotherman Burgess / Knoxville News Sentinel via AP

An African lion named Tsavo is seen during cancer treatment at the University of Tennessee's Veterinary Medical Center in Knoxville, Tenn. The 11-year-old big cat is undergoing radiation treatment for a large tumor near its mouth.

Tsavo, a 357 pound African lion, received radiation treatments at the University of Tennessee's Veternary Medical Center on a cancerous tumor near the big cat's mouth.

This was the fourth, and last, of Tsavo's radiation treatments. At his first visit, the tumor measured 10 centimeters — about the size of an orange. At this one, it measured about 6 centimeters, smaller than a lime. With any luck, the radiation has killed the cancer's DNA so that the tumor will continue to shrink over the next four weeks. If not, Tsavo will have surgery to remove it.

--The Associated Press

The photographs were shot on July 6, but made available to msnbc.com today.

Amy Smotherman Burgess / Knoxville News Sentinel via AP

Assistant professor of radiation oncology Dr. Nathan Lee prepares an African lion named Tsavo for cancer treatment at the University of Tennessee's Veterinary Medical Center in Knoxville, Tenn. The 11-year-old big cat is undergoing radiation treatment for a large tumor near its mouth.

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