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Seeing the Light: How and Why We're Making Cancer Tumors Glow

Animation of tumors glowing in lung

The Limitations of Surgery in Removing Cancer

Surgery is the front-line of cancer treatment. It is often the first stop on a treatment journey that may include chemotherapy or radiation. Nearly half of all people treated for cancer at Penn will undergo surgery at some point, usually to find out more about the tumor, or to remove the cancer or surrounding lymph nodes.

A cancer surgeon enters the operating room with two goals: to find the cancer and to remove all of it.

Neither is clear-cut.

Advancements in radiology have resulted in tumors being diagnosed at earlier stages and smaller sizes than in the past. Surgeons rely on their eyes and hands to identify cancerous masses that can be as tiny as one to two millimeters.

Once the cancer is found, removal can task even the most experienced doctor. The human body doesn’t mirror a coloring book with clearly delineated lines. The margins of tumors can be faint and uneven. Surgeons work with the utmost care and precision to ensure that they extract all the cancer.

These limitations were unsettling to Sunil Singhal, MD, Assistant Professor of Surgery, who looked for a way to enhance surgery - for a technique that would help surgeons do their jobs better.

"I was always frustrated when you would tell a patient they were cured and then their cancer would come back," Dr. Singhal says. "I felt that, as surgeons, it was our responsibility to do more, to make sure that we got the entire cancer out."

Near-Infrared Imaging

His insight led to the development of near-infrared (NIR) imaging, currently being tested in clinical trials. If approved by the Food and Drug Administration, NIR imaging will be the first surgical advancement of its kind in several decades — one that could bring a new level of precision to the operating room.

Inspired by glowing decals on the ceiling of his daughter’s bedroom, Dr. Singhal envisioned cancer cells lighting up in a way that might make them more easily recognizable.

NIR imaging attempts to do just that. It relies on a special dye that is intended to reach the tumor and, when lit with a near-infrared camera, glows green. The camera’s rays come from light, rather than radiation, eliminating the side effects or concerns sometimes associated with radiation.

Testing, Testing

Preliminary testing on canine patients at Penn’s School of Veterinary Medicine and current trials with human patients show promise. If approved, this technique could be useful in the treatment of a number of cancers including lung and prostate.

The future rests with the dye. Different dyes target the cancerous area in different ways and may provide varying levels of accuracy. Dr. Singhal is looking beyond his early dyes and partnering with industry to develop new generation dyes. Improved dyes may be brighter and more specific so that surgeons can see smaller numbers of cells.

"This is truly the tip of the iceberg. It's a new field, but there's a lot of work that still has to come from this," says Dr. Singhal.

The Center for Precision Surgery

In order to develop this line of research, the ACC has established a new Center for Precision Surgery, led by Dr. Singhal. The center, which opened in October 2015, brings together surgeons who specialize in different cancers and provides a platform for surgical innovation.

To date, Dr. Singhal and the team of surgeons have tested imaging technology in the operating room on more than 250 patients enrolled in surgical clinical trials. Cancer types under investigation include:

  • Bladder
  • Brain
  • Breast
  • Ear, Nose and Throat
  • Fallopian Tube
  • Gastric/Stomach
  • Kidney
  • Lung
  • Melanoma
  • Ovarian
  • Pancreatic
  • Peritoneal
  • Prostate
  • Sarcoma
  • Uterine

The group has also discovered many common challenges.

“The center is allowing us to address problems faster because we are working together and in a cross-disciplinary fashion,” says Dr. Singhal. He continues to perfect his technique, looking for ways to enhance the glow.

A Lung Cancer Patient's Experience with Near-Infrared Imaging

After being diagnosed with lung cancer, Francie Howat decided to participate in Dr. Singhal's clinical trial. He and his team used a special dye that would illuminate the cancerous tumors. The glowing dye showed a cancerous tumor that doctors would've otherwise missed.

Watch Francie's story to see how the surgery worked.

About This Blog

The Focus on Cancer blog discusses a variety of cancer-related topics, including treatment advances, research efforts and clinical trials, nutrition, support groups, survivorship and patient stories.

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