A doctor looking at brain scans.
Chemo wafers are often used to treat types of brain cancer.

What Are Chemo Wafers?

What are chemo wafers? A chemo wafer, specifically a Gliadel wafer, is medication that is implanted to treat certain type of brain cancers. The wafer is made of carmustine. This is a chemotherapy drug that works by sticking to one of the cancer cell’s DNA strains, which then slows or stops cancer cell growth. There’s also prolifeprosan 20, which helps to control the release of carmustine in the brain.

What Is the Purpose of Chemo Wafers?

The wafer is placed in the brain following surgery to remove the brain tumor. Over the course of two to three weeks, the wafer slowly dissolves and releases the medicine into the brain. The number of wafers implanted is dependent on the amount of space available, with up to eight wafers being placed on the surface of the resected tumor beds in recurrent tumors, after initial tumor resection. The goal of this therapy is to kill any cancerous cells that remain after tumor removal.

What Types of Cancers Are Chemo Wafers Used to Treat?

Chemo wafers are used to treat a certain types of brain tumors called malignant gliomas, including glioblastoma multiforme (GBM), anaplastic astrocytoma, anaplastic oligoastrocytoma and anaplastic oligodendroglioma.

Malignant gliomas are the most common type of primary brain cancer in adults. The current standard treatment for malignant gliomas includes surgical resection of the tumor followed by radiation therapy. If the tumor recurs, systemic chemotherapy is delivered orally or intravenously.

Unfortunately, the median survival rate is poor even though there have been advancements in surgical techniques and delivery of radiation therapy; therefore, chemo wafers provide a new approach to the delivery of chemotherapy in individuals with malignant gliomas that may improve survival rates.

Pros and Cons of Chemo Wafers

The pros:

  • Chemo wafers provide targeted therapy directly to the area involved, often resulting in fewer systemic side effects.
  • Chemo wafers have been shown to enhance survival by shrinking the tumor, delaying further growth, or reducing the risk of the cancer returning.
  • When you have chemo wafers implanted, you are monitored more closely by your oncologist, which you may find reassuring.

The cons:

  • There are side effects associated with the chemo wafer.
  • You may find increased visits with your oncologist exhausting.
  • Chemo wafers do not perform well for all individuals, so it may not work for you.
  • Chemo wafers have the potential to destroy healthy cells.
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Side Effects of Chemo Wafers

As with any medication, there are side effects associated with chemo wafers. The list of potential side effects is quite extensive; however, side effects tend to resolve once treatment is stopped.

The symptoms experienced, and the severity of the symptoms, varies among individuals. Some commonly reported side effects:

  • Nausea and vomiting
  • Constipation
  • Back and/or abdominal pain
  • Confusion
  • Drowsiness
  • Swelling, redness and warmth of the surgical site
  • Slowed wound healing
  • Signs of infection including fever and/or stiff neck
  • Mood changes including anxiety and/or depression
  • Chest pain
  • Weakness in the arms or legs
  • Difficulty with walking
  • Difficulties with speech
  • Hair loss
  • Skin rash
  • Headaches
  • Seizures

Additionally, these side effects may occasionally occur:

  • Blood clots (pain, redness and swelling)
  • Allergic reaction (rash, itching, swelling, severe dizziness, difficulty breathing)
  • Increased glucose levels in the blood, which may lead to diabetes
  • Swelling of the arms and legs
  • Increased fluid pressure within the skull (confusion, severe headache, and/or vision changes)
  • Inability to move your face
  • Changes to nerves that may include numbness, tingling, or decreased sense of touch
  • Difficulty falling and/or staying asleep
  • Decreased red blood cells causes paleness, tiredness, breathlessness and an increased risk of infection
  • Increased white blood cells
  • Eye issues such as blurred or double vision, pain and swelling of the eyelid lining
  • Diarrhea
  • Bladder incontinence
  • Decreased levels of potassium and sodium in the blood

Rarely, you may experience:

  • Brain bleeding
  • A narrowing or blocking of the brain blood vessels

It’s important to discuss any side effects that you experience with your oncologist right away. They have determined that the benefits of this medication outweigh the associated risks. Close monitoring can help to minimize your risk of suffering from serious side effects.


While additional research is warranted, the available research suggests that the use of chemo wafers for the treatment of malignant gliomas can help to improve survival. If you’ve been newly diagnosed with malignant glioma or have had a recurrence of your cancer, you should consider speaking to your oncologist about treatment with chemo wafers to determine if you’re a suitable candidate for this innovative treatment option.