Pancreatic Cancer

Background

Every year, more than 30,000 new cases of pancreatic cancer are diagnosed in the United States.  Unfortunately, there are also approximately 30,000 deaths per year making pancreatic cancer the fourth leading cause of cancer death.

Although the majority (approximately 95%) of pancreatic tumors are composed of adenocarcinomas, other types of tumors such as pancreatic lymphomas have a much more favorable prognosis.  The treatment for these more rare tumor types differs somewhat from the adenocarcinomas.  The following discussion relates primarily to pancreatic adenocarcinomas.

Treatment Alternatives

Despite aggressive treatment modalities including surgery, radiation therapy, and chemotherapy, the overall survival for this disease has not changed significantly in the last 20 years. 

Patients are generally categorized into those with resectable disease, those with locally advanced disease, and those with metastatic disease.  Historically, surgery offers patients the best chance of long-term survival. 

However, recent advances in other treatment modalities such as radiation therapy and chemotherapy have lead to other promising therapies, especially in situations where the pancreatic tumor cannot be removed surgically.

Stereotactic Radiosurgery

Stereotactic radiosurgery is a method of delivering highly accurate, focused doses of radiation to tumors while minimizing the dose to surrounding normal tissues.  Radiation oncologists and neurosurgeons have been using this technique for decades to treat brain tumors.  Improvements in targeting and delivering radiation to tumors have now allowed us to treat tumors outside of the brain. 

Setup and Treatment Planning

Prior to radiosurgery, 3 - 5 gold seeds are implanted into the tumor as fiducial markers.  These markers are visible to normal diagnostic x-rays and are used to track the position of the pancreatic tumor during radiosurgery.  The markers are placed through a needle under CT guidance.  This procedure takes about 1 hour and is performed by interventional radiologists on an outpatient basis.

Approximately 1 week after the seeds are placed, a treatment planning session is scheduled.  At this time, a custom mold will be made to hold the body in place during the radiosurgery.  Next, a specialized pancreatic protocol CT scan will be completed with the patient lying in this custom made alpha cradle.  The images are downloaded into our treatment planning computer and a customized radiosurgery plan is developed according to each patients' anatomy and the shape/location of the tumor.

Team Effort

A team including a radiation oncologist, a pancreatic surgeon, an interventional radiologist, a diagnostic radiologist, a physicist, an oncology nurse, and a radiation therapist will all be involved in different aspects of patient care. 

We strongly believe that by bringing together a team of highly trained individuals with different areas of expertise, our patients will benefit by receiving the highest quality of care possible.

Treatment Delivery

On the day of radiosurgery, we give patients an anti-nausea pill to take 1 hour before the scheduled treatment.  The actual radiosurgery takes place over a period of 3-5 hours. 

Patients are allowed to eat a normal meal and take all of their normal medications.  After the radiosurgery, patients are instructed to eat a light dinner and take another anti-nausea pill later in the evening. 

What to Expect

In the patients that we have treated so far, the majority of them have no side effects related to the radiosurgery.  They are able to carry out all of their normal activities without interruption.  In a minority of patients (approximately 10%), we have observed transient episodes of mild nausea and increased abdominal pain.  These symptoms were all successfully treated with medications and lasted less then 24 hours.  They all resolved spontaneously.

In a recently completed study at Stanford Medicine, patients were treated with radiosurgery at a "low," "middle," and "high" dose.  In 100% of patients treated at the "high" dose, all patients had their pancreatic tumors controlled for the rest of their life.  In other words, these tumors either stopped growing or decreased in size following radiosurgery.  In most patients, there was also a corresponding decrease in the level of detectable CA 19-9 (serum tumor marker for pancreatic cancer). 

None of these patients had any significant treatment related acute toxicity.  As an unexpected benefit, most patients who had pain prior to radiosurgery had a decrease in their pain within a few weeks following treatment.  Some patients had such dramatic reduction in their pain that they were able to stop taking all of their pain medications.  Radiosurgery for pancreatic cancer has had a significant impact on improving the quality of life for our patients.

Phase II Study

We have recently opened a phase II study at Stanford for pancreatic cancer patients with locally advanced/unresectable tumors.  Eligible patients must have tumors that have not spread beyond the pancreas. 

In this study, we are treating patients now with conventional chemo/radiotherapy followed by radiosurgery to the pancreatic tumor.  Following this treatment, patients will be restaged and can receive either additional chemotherapy or undergo surgical resection if their tumor regresses enough to be removed surgically.

Recent Publication

Phase I Study of Stereotactic Radiosurgery in Patients with Locally Advanced Pancreatic Cancer. Int. J. Radiation Oncology Biol. Phys., Vol. 58, No. 4, pp. 1017 - 1021, March 2004.

To view this article, click here

Phase II Study to Assess the Efficacy of Conventionally Fractionated Radiotherapy Followed by a Stereotactic Radisurgery Boost in Patients with Locally Advanced Pancreatic Cancer. Int. J. Radiation Oncology Biol. Phys., Vol. 63, No. 2, pp. 320 - 323, Oct. 2005.

To view this article, click here

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