The American Cancer Society (ACS) estimates that more than 25,000 malignant tumors of the brain or spinal cord will be diagnosed in 2022. They also note that survival rates for brain and spinal cord tumors vary widely, depending on the type of tumor and other factors such as the patient's age, grade of the tumor, and its location and size.
UC San Diego (UCSD) Health has introduced a new, highly targeted, and precisely placed radiation therapy designed to delay tumor growth while protecting healthy tissue in some patients with brain cancer. The facility is the first hospital system in San Diego to offer the treatment option, which it says "may extend the lifespan for certain patients and improve their quality of life."
The FDA-cleared approach, known as GammaTile, utilizes small radiation seeds, or brachytherapy, which are implanted at the tumor site during surgery and naturally absorbed into the body to treat malignant and recurrent brain tumors, including gliomas, glioblastomas, and meningiomas. UCSD Health began offering the new brachytherapy treatment in July 2022.
Each therapeutic seed-approximately the size of a postage stamp-contains radiation sources embedded in a collagen tile that combine to deliver a "precise, targeted dose of radiation," according to the health care system. The radiation immediately begins targeting tumor cells in the area where the tumor is most likely to recur.
With a goal of killing any residual tumor cells, brachytherapy "is not a brand-new concept," noted Marc Schwartz, MD, a neurosurgeon at UCSD Health.
"However, this new option is very simple and provides the opportunity to offer effective treatment that may extend a patient's life," he stated. "We frequently see patients who have malignant brain tumors, either primary or metastatic, who have already received treatment and are continuing to do well clinically, but have recurring tumors that limit treatment options."
The previous standard of care for patients with operable brain tumors has been surgical removal of the tumor, followed by adjuvant therapy, including radiation and chemotherapy. However, traditional radiation is delivered in as many as 30 treatments extending over a period of several weeks.
With the GammaTile approach, the seed absorbs into the tissue over time after the radiation has been delivered, according to UCSD Health. A clinical trial evaluating the treatment found that the approach resulted in nearly twice as many tumor-free months compared to prior treatment for patients with recurring brain tumors located in the same area.
Brachytherapy, or close distance therapy, is a radiation therapy technique that offers "a unique advantage over other techniques through the placement of radiation sources exactly in the target area," noted Dan Scanderbeg, PhD, Professor and Associate Director in the Division of Medical Physics at UC San Diego School of Medicine.
This new brachytherapy option leads to less dose to normal tissues, offering another treatment option for some patients with operable brain cancers, "and is particularly effective when working with recurrent disease and areas that have had prior radiation therapy," added Scanderbeg. "It also allows for a highly targeted radiation dose to be applied to the target area while sparing normal brain tissue."
Further, placement at the time of surgery eliminates the need for additional visits for radiation therapy sessions that be burdensome on the patient and their families, he noted, stated that GammaTile is currently indicated only for malignant or recurrent brain tumors, while breast cancer patients are not able to receive the therapy.
This new radiation seed is offered to patients who have no other effective treatment option and otherwise poor prognoses, added Schwartz. "If they respond to the therapy, it may provide them with more time."
Mark McGraw is a contributing writer.