Having a Heart to Heart Talk with Yourself About Your Pet’s Cancer Diagnosis

Cure Pet Cancer

November is National Pet Cancer Awareness Month. One in every four dogs and one in every five cats will develop cancer in their lifetime and @amcny is doing its part to raise pet cancer awareness by tweeting to #CurePetCancer to raise awareness.

Since cancer diagnoses are common in pets, many of my readers will face the difficult task of choosing cancer treatment decisions for their pet. Here is a list of questions you should ask yourself as you work through that decision-making process.

What kind of cancer specialist does my pet need?
Veterinary cancer specialists are not all the same. At AMC, we have three different types of cancer experts for pets: those that focus on administering chemotherapy, some who specialize in delivering radiation therapy, and the third type have special training in surgical oncology. We all know the basics of cancer treatment principals, but have different strengths within that core information. Your pet may need a consultation with one of us or all of us, depending on the type of cancer that has been diagnosed. The answer to this question lies in the biopsy because the type of tumor your pet has dictates the treatment options.

What kind of treatment is the oncologist recommending and is it right for my pet?
There are three main treatments for cancer: surgery, radiation and chemotherapy. Not every treatment is appropriate for every type of cancer and based on the biopsy, an oncologist will discuss what options are available to your pet and the expected outcome for each treatment option. Chemotherapy and radiation therapy require multiple treatments over several weeks to months. Surgery typically requires only a few visits to the hospital and has the highest chance of curing certain cancers. Cancer is most common in older pets and the grey muzzle set is also most likely to have other medical conditions which have to be taken into consideration in making the decision to pursue cancer treatment.

Do I have the resources to undertake the recommended treatment?
This question isn’t just about money, although cancer treatment can be costly. Another consideration when making the decision to treat your pet’s cancer is your time. Sometimes a trip to the surgical oncologist is all that is needed and other times 20+ trips are required for a course of chemotherapy. Be sure you understand what is required for the recommended treatment protocol. Your emotional resources count too. Maybe you are also caring for a seriously ill human family member and cancer treatment for the pet is more than you can handle. Or maybe it is the other way around and you can’t bear to lose two family members at once.

What is the prognosis for my pet with and without treatment?
This is a loaded question. The question is fair, but pet families who choose not to treat their pet’s cancer don’t often consult with an oncologist. That means oncologists, like me, don’t always have a good handle on the prognosis without treating many types of cancer.

If you have decided to make an appointment for a consultation with a veterinary cancer specialist, read about fancy cancer words that we try to keep out of our conversation with you, but sometimes accidentally slip into a conversation about treating your pet. Being prepared for a visit with a specialist will help to make sure all your questions are answered.

The Difference Between Diagnostic Radiology, Radiation Therapy and Interventional Radiology

radiation therapy

At first glance, these three disciplines within veterinary medicine seem pretty much the same, but at the Animal Medical Center, diagnostic radiology, radiation therapy, and interventional radiology represent three different groups of veterinarians with three very different sets of background and training. What ties these three disparate groups together is their use of radiation to diagnose and treat disease.

Diagnostic Radiology
These days you are more likely to find a Department of Diagnostic Imaging in a hospital than a Radiology Department. Radiology is an older term, used when x-rays were the only testing modality using radiation available in medicine. Today, AMC’s Diagnostic Imaging Service uses not only traditional x-rays but also ultrasound, computed tomography (CT) scans, and magnetic resonance imaging (MRI) in the diagnostic evaluation of patients. AMC’s Diagnostic Imaging Service also has a fluoroscopy unit, which is like a video x-ray. This machine allows us to watch bodily functions like blood flow or swallowing in real time. To see an example of fluoroscopy, read about Molly the Ganaraskan. Every veterinarian at AMC depends on our diagnostic imaging team for their expertise in imaging sick pets and helping us to make an accurate diagnosis.

Radiation Therapy
A very accurate description, AMC’s Radiation Oncology Service uses radiation to treat tumors. Specifically, we have a linear accelerator (linac), a giant machine that creates various types of radiation depending on patient needs. Our state-of-the-art linac can make electrons for superficial treatments, produce high energy pinpoint beams for stereotactic radiosurgery, and stereotactic body radiation therapy. Diagnostic Imaging’s CT scanner interfaces with Radiation Oncology’s 3-D computer planning system. The interface allows the linac’s multileaf collimator to sculpt the radiation beam to precisely target the tumor being treated. The veterinarians working in radiation therapy have training in both the physics of radiation as well as the management of cancer.

Interventional Radiology
Specialists in interventional radiology use minimally invasive techniques to make image-guided diagnoses and also deploy high tech treatments for a variety of diseases. Using a range of techniques which rely on the use of images generated by diagnostic radiology equipment such as fluoroscopy, ultrasound, CT scan, or MRI imaging, the interventional radiologist precisely targets various organs with treatments such as stents, occluders and medications. Watch a video where AMC’s interventional radiology team uses fluoroscopy to close off abnormal blood vessels in the liver. The veterinarians in our Interventional Radiology Service have diverse backgrounds in surgery, internal medicine plus specialized training to use minimally invasive equipment.

Linked together by their use of radiation as a diagnostic and therapeutic tool, diagnostic radiology, radiation therapy and interventional radiology are just a few of the highly trained specialists at AMC working to make sick pets healthy again.

Radiation Therapy Machines: Machines and Methods

radiation therapyMay is Pet Cancer Awareness Month. Since the goal of Pet Cancer Awareness Month is to educate pet owners about cancer, I am going to devote this week’s blog to clearing up some of the confusion over the various forms of radiation therapy. Radiation therapy machines treat cancer by delivering high energy radiation to a tumor, killing the tumor cells. There are several types of prescriptions for the dose of radiation delivered to a tumor.

Radiation Oncologists and Their Machines
A number of different machines are available to administer radiation:

  • The Animal Medical Center uses a Varian Clinac® linear accelerator (linac) to deliver radiation therapy to tumors. Our linac has a multi-leaf collimator (MLC) which moves while the radiation beam is on, sculpting the beam around the tumor, protecting normal structures from radiation. Here is a MLC in action. Radiation using a MLC is called image modulated radiation therapy (IMRT). We also can utilize a 3-dimensional computerized treatment planner. The AMC’s linac can also be used to deliver stereotactic treatments. I will expand on stereotactic treatment below.
  • The Cyberknife® is a linac merged with a robotic arm, which allows the machine to dance around the patient. The radiation beam turns on and off, zapping the tumor from multiple angles. Treatment from multiple angles creates a treatment field conforming to the shape of the tumor.
  • A Tomotherapy machine is a cross between a linac and a CT scan. Tomotherapy creates an image of the tumor immediately prior to treatment and uses the image to direct treatment. Both imaging and treatment occur using the same machine.
  • The Gamma Knife® treats brain tumors. And although the word knife suggests this machine does surgery, it does not. It precisely delivers a high dose of radiation to a very focal area in the brain while avoiding normal brain tissue.

Radiation Therapy Prescriptions
Radiation can be prescribed in a number of different fashions. The standard for many years has been administration of multiple small doses of radiation with the goal of eradicating the tumor. This course of treatment is often referred to as “definitive” or “hyperfractionated” therapy. Oncologists commonly recommend this type of treatment to follow when a surgical procedure has not removed every last tumor cell. The opposite of hyper is hypo and oncologists often use a few large doses of radiation to treat tumors that cannot be removed by surgery. Oral melanoma is a good example of a tumor treated this way.

The most advanced dosing schemes for radiation therapy are Stereotactic Radiation Therapy (SRT), which includes both Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT). Stereotactic treatments use high doses of radiation given over one to three treatments. On-board imaging equipment allows precise delivery of the radiation dose in stereotactic treatments. Stereotactic radiosurgery, like the Gamma Knife, is not a form of surgery. It is typically administered in a single dose and is reserved for treatment of brain tumors. Stereotactic radiosurgery was the first type of stereotactic radiation therapy. Stereotactic Body Radiation Therapy, as the name implies, is administered outside the brain. The AMC’s Clinac is able to deliver both SRS and SBRT.

The “Best” Type of Radiation Therapy
No one radiation therapy machine or prescription is “best.” The type appropriate to treat your pet’s tumor will be determined by the biopsy results, surgical resectability of the tumor, and size and location of the tumor. The AMC has a board certified radiation oncologist who can help you make the best decision possible to manage your pet’s cancer with radiation.

National Pet Cancer Awareness Month: Pet Cancer Treatment Options, Part I

November has been designated National Pet Cancer Awareness Month to raise awareness about the causes, prevention and treatment of dogs and cats with this terrible disease. According to the Morris Animal Foundation, there are six million new pet cancer diagnoses every year. That number of diagnoses translates to millions of pet cancer treatments each year. Traditionally, surgery, chemotherapy and radiation therapy were considered the mainstays of cancer treatment in both people and pets, but recent innovations add immunotherapy and targeted drug therapy to the growing list of cancer treatments for pets.

To raise awareness of the possible treatments for pet cancer, Fur the Love of Pets will feature this two-part blog on cancer treatment options in pets.

Surgery
Surgical removal as a treatment for cancer has been practiced since Roman times. Perhaps because of a lack of surgical skill, coupled with a lack of techniques for general anesthesia, surgery was not particularly effective, if we believe the Roman physician Celsus. He wrote, “After excision, even when a scar has formed, none the less the disease has returned.” Today we know much more about how to treat canine and feline cancer patients with surgery. Tumors such as canine breast cancer, soft tissue sarcomas and mast cell tumors are potentially cured by surgical excision alone. The key to treating many types of tumors with surgery is to remove a wide swath of normal skin and tissue around the tumor to ensure complete removal of the cancer-causing cells. Anyone with a pet treated with surgery for mast cell tumor or soft tissue sarcoma can attest to the fact that the actual incision was much bigger than they anticipated. Current guidelines recommend as much as 3cm (1.25 inches) of normal tissue be removed on all sides of the tumor as part of a cancer surgery.

Surgical treatment of pet cancer recently became highly specialized when the American College of Veterinary Surgeons (ACVS) recognized the Veterinary Society of Surgical Oncologists (VSSO). Members of VSSO have achieved a high level of competence in cancer surgery though their participation in a surgical oncology fellowship following certification by ACVS.

Radiation Therapy
The second cancer treatment to be widely used in humans was radiation therapy. Veterinarians began using radiation therapy in pets in the early 1980s. Board certified veterinary radiation oncologists treat a wide variety of tumors including brain tumors, thyroid tumors and melanoma.

The radiation therapy equipment The AMC currently uses is our third machine since 1989. The first two used cobalt as the radiation source. Now we have a linear accelerator with electron beam capabilities, image modulated radiation therapy and stereotactic radiosurgery – a huge advancement in technology from our first rudimentary cobalt machine. To ensure exact positioning for each treatment, a customized “bed” is created for each patient. View a video of one of our vacuum assisted positioning devices being used in a feline patient.

Want to learn how to recognize signs of cancer in your pet? View our slide show on the “Ten Warning Signs of Cancer in Pets.”

When Life Gives You Lemons, You Need a Buddy

Tracy and her 14 year old grey tabby, Baller, have experienced a few bumps in the road this past year. In April, Tracy noticed Baller, named after a rap song, was defecating outside his litter box. He also had diarrhea, but he didn’t seem very sick since he was eating well and was his usual playful self. Her neighborhood veterinarian examined Baller and found two pounds of weight loss. Tracy thought she could breathe easier when she heard the blood tests were normal, but an abdominal ultrasound revealed Baller had colon cancer.

Minimally Invasive Testing
Tracy brought Baller to The Animal Medical Center for a consultation with one of our board certified oncologists. Baller’s oncologist, Dr. Maria Camps, explained the most common type of cancer in cats is lymphoma, and recommended a minimally invasive approach to diagnosis since lymphoma is treated with chemotherapy, not surgery. Ultrasonography was used to direct a small needle into the colon tumor and retrieve cells from the tumor. Within hours, Tracy found out she and Baller were facing an uphill battle against lymphoma. The anticipated survival time for a cat with lymphoma treated with chemotherapy is less than one year.

Chemotherapy Helps
Dr. Camps actually gave Tracy so much hope, and Dr. Mollica, Baller’s regular veterinarian and a former AMC intern, was also very supportive. These two veterinarians really gave Tracy that extra oomph she needed to continue Baller’s treatment. Ms. Koch says, “I knew the chemo was working almost immediately. Right after his first treatment he was feeling better again. He is one to make it known when he has issues by hiding under the bed, not eating and not able to use the bathroom. But, it was amazing that right after his first treatment he was back to his normal routine. I thought it [the chemotherapy] would help a bit, but I didn't realize how much better it would make him feel. He was like a whole new cat, which makes me sad because who knows how long he was feeling bad before he really started to show it.”

About one third of the way through his prescribed course of chemotherapy, and just when Baller’s cancer seemed to be in control, a roadblock obstructed the path to further cancer treatments; Tracy was laid off.

Buddy Fund Helps Out
This is where the Buddy Fund comes in to assist Tracy and Baller. The Buddy Fund, one of AMC’s Community Funds, was established to provide financial support for AMC patients with cancer whose owners could otherwise not afford to treat their four-footed family members. The name of the Buddy Fund has a double meaning. The original donors to the fund had a very special cat named Buddy and the fund acts as a “buddy” to owners of pets with cancer. Baller’s oncologist recommended him for the fund because he was responding exceptionally well to the prescribed course of chemotherapy. Discontinuation of treatment would put him at high risk for relapse of his cancer.

Thanks to the Buddy Fund and its generous supporters, Baller completed his chemotherapy protocol just before Thanksgiving and without missing a single treatment. At his most recent follow up appointment he was given a thumbs up because no tumors were detected during the examination. Going forward, Baller will continue to be monitored for tumor recurrence. As the one year anniversary of his diagnosis approaches, everyone has their fingers crossed for Baller. Tracy looks forward to a time when she is employed again and can be a “buddy” to another deserving cat through a contribution to AMC’s Buddy Fund.

How Many Ways Can the Thyroid Malfunction?

The thyroid gland sits in the neck of dogs and cats, just below the voice box, and controls metabolic functions. Most of the time, a routine physical examination cannot detect the organ if it is normal. Last week, my patient list ran the gamut of thyroid dysfunction. Here is a sampling:

A Tail of Two Thyroids

Some days, strange coincidences happen in the waiting room. Today it was two dogs, both with thyroid cancer. Although measuring 15 centimeters in length, Beckey’s thyroid tumor had been surgically removed. The biopsy showed her tumor trying to escape into the lymph vessels and she was waiting her turn for chemotherapy, administered to halt the spread. Her treatment involves intravenous administration of two different chemotherapy agents and Beckey so far has sailed through the treatment with flying colors.

As Beckey was leaving the waiting room, Henry entered. A CT scan showed his thyroid tumor had already spread to the lymph nodes in his neck, precluding surgical removal. He was in for a check-up following completion of four radiation therapy treatments. Careful measurement of his tumor with calipers showed no increase in tumor size. The radiation treatment arrested tumor growth but had given him a sore esophagus. I had warned the owners about this type of side effect before we started treatment and told them to expect it to start resolving about two weeks after he completed his treatment. Henry did not disappoint us. Through telephone triage, we had already rearranged his medications to make his throat less painful. Henry spends summer in the country but in the fall he will come back to The AMC for measurement of the tumor and a chest x-ray.

Old Patient, New Problem

Otra’s family was worried. This cute kitty had completed chemotherapy for intestinal lymphoma about a year ago, but suddenly her weight plummeted. I could see from the look on their faces they were sure the cancer was back. Auscultation of Otra’s heart discovered a very elevated heart rate, prompting a test of her thyroid levels. Overactive thyroid glands ramp up the cat’s metabolism and they lose weight despite eating well, have a high heart rate, and are very peppy. An abdominal ultrasound showed no evidence the lymphoma had recurred and blood tests showed the thyroid was overactive. I sent thyroid-suppressing medications home with the relieved family and planned to reassess the thyroid hormone levels in two weeks.

Porterhouse to Pork Chop

Every time I saw Mango to follow up on a skin tumor that had been completely removed via surgery, she had gained another pound. This 60-pound Portuguese Water Dog should have weighed 50 pounds. The owners took her swimming, fed her diet food from feeding toys, and still she gained two more pounds. During an evaluation for a urinary tract infection, we noted her thyroid hormone levels were borderline low. When we retested the levels three months later, we confirmed diagnosis of hypothyroidism. Low thyroid function, the opposite of Otra’s problem, can cause weight gain. Since she started treatment with thyroid supplementation, Mango has lost nearly 6 pounds and gone from a 20-ounce porterhouse to a 4-ounce pork chop over the past few months!

There you have it, thyroid malfunction runs the gamut of disease: overactive, underactive, and two different tumors, all in one tiny organ.