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Our Team

Cancer HealthCare Associates is dedicated to enhacing our patient’s quality of life through clinical excellence and personlized care.

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Expert Oncologists

We understand that cancer care is about comfort, compassion and access to advanced treatment, so we focus on treating the patient not just the disease.Our oncology team includes radiation oncologist Dr. Martin Keisch, surgical oncologist Dr. Seza Ali Gulec and medical oncologist and hematologist Dr. Enrique Davila. Additionally, our Aventura/Hollywood urology team includes Dr. Jay Kim, Dr. Giridhar Talluri and Dr. Maurice Strahlberg.Leading our staff, Vicki Balabous manages operations of all facilities. Our board-certified medical physicist, Vince Pisciotta, oversees the radiation facility at our Miami Shores Oncology Center.


Dr. Martin Keisch

Radiation Oncology

Martin E. Keisch, MD, a board-certified radiation oncologist, is president of Cancer HealthCare Associates (CHCA).

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Dr. Jay Kim


Jay Kim, MD, is the Director of Urology at Aventura Hospital and Medical Center and a board-certified urologist.

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Dr. Giridhar Talluri


Giridhar Talluri, MD, is a board-certified urologist with two decades of experience in urology and urology research.

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Vicki Balabous, MBA


Vicki Balabous, MBA, is vice president of operations with Cancer HealthCare Associates (CHCA).

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Leonard Toonkel, MD

Radiation Oncologist

Leonard Toonkel MD is a board certified Radiation Oncologist with over 40 years of experience.

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Martin Keisch, MD

Martin E. Keisch, MD, a board-certified radiation oncologist, is president of Cancer HealthCare Associates (CHCA). Dr. Keisch has extensive expertise in breast, prostate and GYN brachytherapy. He currently serves as an investigator in the Mammosite Multicenter DCIS trial and the Mammosite Registry trial for the American Society of Breast Surgeons.

He graduated with honors from Tufts University School of Medicine in Boston, MA, during which he obtained a research grant and completed studies of endothelial cell motility and cytoskeletal structure modulation by growth substrate. Dr. Keisch completed his residency in radiation oncology at the Mallinckrodt Institute of Radiology at Washington University Medical Center in St. Louis, MO, where he served as Chief Resident in Radiation Oncology. While completing his residency, he developed a computer-based training system for radiation oncology and worked as an American Cancer Society research fellow.

Prior to joining University of Miami Hospital, Dr. Keisch worked as a radiation oncologist in Miami Beach and as Medical Director for Radiation Oncology for Sharp Healthcare in San Diego. Dr. Keisch’s professional affiliations include serving as a member of the University of Miami Hospital Cancer Committee and as the cancer liaison physician to the American College of Surgeons. He also is a member of the finance committee of the American Brachytherapy Society. His other affiliations include the American Society of Therapeutic Radiation Oncology, the American College of Radiology, ESTRO, the Fletcher Society; American Radium Society, the American College of Radiation Oncology and the American Brachytherapy Society.

Dr. Keisch can be reached by phone at (305) 545-6685 or by e-mail at [email protected].


Jay Kim, MD

Jay H. Kim, MD, is a board-certified urologist with more than two decades of experience practicing urology in South Florida, specializing in minimally invasive and robotic surgery.  After graduating from Northwestern University and the University of Illinois College of Medicine, he completed his surgery and urology training at the Maimonides Medical Center in Brooklyn, NY.  During his training, Dr. Kim worked as a research fellow at the Memorial Sloan-Kettering Cancer Center in New York City.  Dr. Kim has served on a number of hospital committees during his career, including Chief of Surgery and Chief of Urology at Aventura Hospital and Medical Center.

His professional affiliations include the American Urological Association, American Medical Association, and the Endourological Society.


Giridhar Talluri, MD

Giridhar Talluri, MD, is a board-certified urologist with two decades of experience in urology and urology research. After completing his medical education at Guntur Medical College in Guntur, India, he worked as a Research Fellow in Immunobiology at Johns Hopkins University then served as Chief Resident in Urology during his urology and surgery residencies at the Maimonides Medical Center in Brooklyn. During this time, Dr. Talluri published extensively and was twice awarded for his outstanding research, in addition to being granted the Pfizer Scholars in Urology Award.

Following his residency, Dr. Talluri continued his training with a fellowship in Kidney and Pancreas Transplantation at the Cleveland Clinic Urology Institute. Dr. Talluri’s professional affiliations include the American Urological Association, the American Medical Association and the American College of Surgeons.


Vicki Balabous, MBA

Vicki Balabous, MBA, is vice president of operations with Cancer HealthCare Associates (CHCA). Ms. Balabous, who has more than a decade of experience as an administrator of hospitals and medical facilities, oversees all aspects of CHCA’s administration, including financial management and business planning and development.

Ms. Balabous earned a master’s degree in business administration from the University of Miami (UM) in 2005 and a bachelor’s degree in biology and sports medicine from UM in 1997.

Prior to joining CHCA, she served as director and assistant administrator with the University of Miami Hospital. Her work involved a wide variety of responsibilities, including recruiting physicians to the facility and providing assistance with the management of the physicians’ practices, directing the hospital’s oncology data center and sleep disorders center and managing the development, leasing and management of medical office space.

Ms. Balabous can be reached by phone at (305) 545-6685 or by e-mail at [email protected].


Leonard Toonkel, MD

Leonard Toonkel MD is a board certified Radiation Oncologist with over 40 years of experience. Dr. Toonkel was previously the chairman of Radiation Oncology at Mt Sinai Medical Center on Miami Beach for 25 years. He specializes in prostate and breast cancer and has lectured extensively on these subjects throughout his career. Dr. Toonkel obtained his Bachelor in Science and his Medical Doctor degree from the University of Miami. He also completed his Internal Medicine Internship at the University of Miami.
He then completed 2 residencies in Therapeutic Radiology at the University of Miami and MD Anderson Hospital in Houston Texas. He completed his fellowship in Radiation Oncology at MD Anderson in Houston.


CHCA offers superior service in radiation oncology, surgical oncology, medical oncology, hematology and urology. We specialize in breast and prostate brachytherapy, more commonly known as radiation therapy. Treating hundreds of patients every year, we have earned a reputation for consistently delivering successful outcomes.CHCA’s areas of specialization include:

  • TomoTherapy
  • Breast Brachytherapy
  • Prostate Brachytherapy
  • GYN Brachytherapy
  • Intensity-Modulated Radiation Therapy (IMRT)
  • Image-Guided Radiation Therapy (IGRT)
  • Stereotactic Brain and Body Radiosurgery
  • Breast Cancer Surgical Services (with an emphasis on breast preservation)
  • Hologic Bone Densitometry
  • Lymphedema Massage

Following are comments provided by some of Dr. Keisch’s breast brachytherapy patients:

Maria Diaz, Hialeah, FL

I thank God and Dr. Keisch every day for giving me a second chance. Dr. Keisch is marvelous, and I will follow him wherever he goes. I went to another hospital and they wanted to perform surgery, but my daughter insisted I get a second opinion. Dr. Keisch gave me radiation therapy and saved my breast. I am eternally grateful to him. May God bless him.

Debbie Arbelo, Hialeah, FL

Dr. Keisch always made me feel as if I was a partner and a participant in my medical care, not just a patient. He did the MammoSite, and everything turned out very well. Through it all, Dr. Keisch always made time to listen and answer all my questions. He was very down to earth, and he didn’t talk in terms I couldn’t understand. Just as important, he has a wonderful sense of humor, and I never left his office without a smile. It means a lot that he could make me laugh during such a difficult time in my life. His office staff members are great too, and they had a very positive impact on my life.

Jane Gross, Miami Beach, FL

The brachytherapy allowed me to be finished with treatment in one week instead of 6 weeks of daily sessions. That meant by Thanksgiving instead of New Year. It was over so fast and the holiday season was joyous to say the least. Dr. Keisch is not only a competent, cutting-edge radiologist, he is a kind and compassionate man with a great sense of humor who instills confidence and as much information as you want. He is a rare combination of medical excellence and personal warmth. I highly recommend his services.

Jose Lacera, Miami, FL

I have only good things to say about Dr. Keisch and his staff. The quality of the care is superior, and I always felt I was in the best hands. The entire team is professional, dedicated, and gives personal attention. They go out of their way to make sure that all your questions are answered and make you feel comfortable.

Gerard Attardi, Plantation, FL

Dr. Keisch saved my life. I had been going to a Urologist for a few years who kept giving me biopsies and kept telling me I was okay, and when I finally got to Dr. Keisch I found out I actually had prostate cancer, so I went ahead and did high-dose radiation with Dr. Keisch. That was more than five years ago, and I haven’t had any problems since then. I have met a lot of doctors in my years, and there are many few of them I feel I would recommend. However, I would recommend Dr. Keisch to anyone. He’s very thorough and precise, and he’s a great doctor.

Leon Srebrenik, Surfside, FL

Dr. Keisch is a great doctor. He’s very thorough, and he has very good bed-side manners. He’s very caring and compassionate with his patients. I will follow him wherever he goes.