Arwen is the alpha dog of her Memphis-area household.
"Whatever Arwen wants, Arwen gets," said owner Amanda Stoermer.
The gray poodle is almost inseparable from her poodle pal, Strider, but last year, the elder of the two started having trouble breathing.
"It took a couple weeks to figure out what the problem was," Stoermer said. "(Our veterinarian) did tests, she finally did an x-ray, and there was some suspicious-looking mass in her chest."
A biopsy determined that mass was thymoma, a cancerous tumor that was wrapped around Arwen's heart and lungs.
"Other than the labored breathing, she wasn't having any symptoms, so it was just such a surprise that this big mass was growing in her chest, and I didn't know and couldn't tell, so we just decided we had to do whatever we could as soon as possible," Stoermer said. "When your oncologist starts talking about quality of life, just go home and make her comfortable, that wasn't what I wanted to hear, and I just couldn't let it go at that."
When surgery wasn't enough, Arwen's journey toward recovery led her to the University of Tennessee College of Veterinary Medicine.
She's the first patient to undergo Intensity Modulated Radiation Therapy, or IMRT.
Dr. Nathan Lee, a radiation oncologist at the vet school, said this new way to deliver radiation is much more accurate.
"The difference is that the field shapes are constantly changing throughout the treatment, and the dose rate is constantly changing so that we can modulate, or vary the intensity of the radiation, over the field so that we can target the tumor area and avoid the normal tissues in the area down to a couple of millimeters," he said.
Arwen is set for 20 treatments, one every weekday for an entire month.
Wednesday marked her 13th day, more than halfway through, and the treatment is working. The tumor is shrinking.
"The prognosis now is good to excellent, and I think, before, the prognosis would have been guarded with the size of this mass, the fact that it was wrapping around the heart and involving a lot of the lungs would have limited what we could have done with radiation in the past, and now that we can have this type of treatment, we're shrinking the tumor down and hopefully it will go completely away and we won't have to do any additional follow-up right away," Dr. Lee said.
Arwen, Strider, and her owner have been staying in Knoxville for the treatments, which are expensive - more than $4,000 total - but well worth it, Stoermer said.
"Arwen's very important, and even though some people would say, she's just a dog, she's much more than that to us," Stoermer said. "It just wouldn't be home without Arwen."