Radiation to the Whole Pituitary Compartment Effective at Controlling Cushing’s

Radiation therapy targeting the entire sella — the compartment where the pituitary gland resides at the base of the brain — is effective at controlling Cushing’s disease and should be considered for patients with suspected invasive adenoma tumors, a new study shows.

The study, “Technique of Whole-Sellar Stereotactic Radiosurgery for Cushing’s Disease: Results from a Multicenter, International Cohort Study,” was published in the journal World Neurosurgery.

In patients with Cushing’s disease, excess cortisol levels are caused by a kind of pituitary tumor (adenoma)  that secretes too much adrenocorticotropic hormone (ACTH).

Removing the adenoma using the transsphenoidal approach — a minimally invasive procedure performed through the nose to remove pituitary tumors — remains the first-line treatment for patients with newly diagnosed Cushing’s syndrome. For patients who fail surgery and medical management, stereotactic radiosurgery (SRS) may be used.

SRS is not a surgery in the traditional sense, as it does not require an incision. Instead, SRS uses many focused radiation beams to treat tumors and other problems in the brain, neck and other parts of the body.

While surgery may achieve very good remission rates in patients with an identifiable adenoma, as many as 50 percent of Cushing’s disease patients have no identifiable adenoma on magnetic resonance imaging (MRI) scans. In such cases, surgeons can opt for SRS targeting the entire sella, a procedure called whole-sellar SRS. However, the outcomes of whole-sellar SRS are not fully known.

Researchers conducted an international, retrospective study to analyze the outcomes of Cushing’s disease patients who received whole-sellar SRS.

The study enrolled 68 patients, including 52 who received the procedure for persistent disease, nine whose disease returned after surgery, and seven as their initial treatment.

Patients underwent a type of SRS known as gamma knife radiosurgery (GKRS), which uses small beams of gamma rays to target and treat brain tumors. They were then followed for a mean of 5.3 years.

Whole-sellar SRS was effective at controlling the disease, researchers found. In the five years after receiving the treatment, 75.9 percent of patients achieved a remission. Of those, 86% remained recurrence-free for five or more years.

The mean volume of area targeted using whole-sellar SRS was 2.6 cm3. Researchers discovered that treatment volumes greater than 1.6 cm3 were associated with a shorter time to remission, indicating that targeting a larger portion is more beneficial.

Also, statistical analysis revealed that a reduced dose of radiation was linked to recurrence, suggesting that a higher dose is more advantageous.

Regarding adverse events, 22.7% of patients who underwent whole-sellar SRS developed loss of one or more pituitary hormones.

Researchers also compared outcomes of patients who underwent whole-sellar SRS to those who received adenoma-targeted SRS, of which the latter involves irradiating only the tumor.

Interestingly, there were no differences in remission rate, time to remission, recurrence-free survival, or new endocrine disease development between both groups.

“Whole-sellar GKRS is effective at controlling [Cushing’s disease] when an adenoma is not clearly defined on imaging or when an invasive adenoma is suspected at the time of initial surgery,” the researchers concluded.

From https://cushingsdiseasenews.com/2018/05/25/precise-radiation-pituitary-sella-effective-control-cushings-study/

For Pituitary Tumors, Gamma Knife™ Radiosurgery Offers Better Tumor Control

For many patients with pituitary tumors, initial surgical intervention is followed quickly by Gamma Knife™ radiosurgery. The benefits of using this radiosurgical intervention are many, and can offer better tumor control and a more positive long-term prognosis compared to surgery alone.

San Diego, CA (PRWEB) July 03, 2017

Worldwide, up to 20% of all brain tumors—those confined within the skull—are identified as pituitary adenomas.(1) Each year, almost 10,000 new pituitary tumors are diagnosed in the United States alone, with the vast majority of these tumors being pituitary adenomas. As efforts to improve treatment for patients with pituitary tumors continue, researchers are discovering just how powerful treatment with Gamma Knife™ radiosurgery can be, at facilities like the San Diego Gamma Knife Center® (SDGKC).

Recent studies have shown compelling results for patients who received treatment with Gamma Knife™ radiosurgery following traditional surgery for pituitary tumor removal. Overall, tumor control was achieved with Gamma Knife™ treatment in up to 94% of patients studied.(1) For up to 85% of these patients, tumor control was still achieved 10 years after treatment with the Gamma Knife™.(6)

Pituitary adenomas are typically benign, but they can still cause significant problems for patients due to their location in the brain.(3) Many of these tumors also secrete certain hormones, which can ultimately change the way patients’ bodies function.(3) In most cases, the first line of defense in dealing with pituitary tumors involves surgical removal of as much of the tumor as possible; however, residual tumor tissue can exist in the brain after this process.(4)

Even though many physicians choose surgery as an initial treatment, Gamma Knife™ radiosurgery can be either a primary or secondary choice for the management of pituitary tumors. Most often, Gamma Knife is used as a secondary treatment following surgery.(5) A growing number of studies show that treating patients with the Gamma Knife™ after surgical removal of pituitary tumors is extremely beneficial for patients and can dramatically improve their long-term tumor control results.

Dr. Kenneth Ott, neurosurgeon of SDGKC®, said, “The extreme accuracy of Gamma Knife radiosurgery allows effective treatment of residual pituitary tumors following surgery to remove much of the tumor volume. In my practice, residual tumors which I have operated on are treated with Gamma Knife radiosurgery which almost always stops further growth.”

Dr. Ott continued to explain that Gamma Knife radiosurgery is more effective than prior external beam methods of radiation and avoids complications to near-by sensitive structures. Tumors within a few millimeters of the optic nerves can be safely treated because of the frame-based fixation and software advantages of Gamma Knife. Tumors which are slowly growing can also be effectively treated without the need for surgery, as long as there is no visual loss from tumor compression of the optic nerves.

Patient outcomes can also be influenced by how soon after brain surgery they receive treatment with the Gamma Knife™. In many cases, patients benefit the most from early intervention with radiosurgery; some studies have suggested that patients who receive Gamma Knife treatment more than six months after their initial surgery are at a significantly greater risk of pituitary tumor progression nearly six years post-surgery.(7)

“Pituitary tumors, in general should be treated before the tumor compresses the overlying optic nerves,” said Dr. Ott. “The earlier the treatment begins, the better. The final decision regarding Gamma Knife should be made on a case-by-case basis by a surgeon who is experienced in surgery and radiosurgery.”
About San Diego Gamma Knife Center:
Since its opening, the San Diego Gamma Knife Center® has treated over 4,000 patients with various brain disorders from around the world. The facility is equipped to provide advanced radiosurgical treatment for a variety of conditions, including metastatic brain tumors, primary brain tumors, arteriovenous malformations, and functional disorders such as trigeminal neuralgia and cluster headaches.

On the campus of Scripps Memorial Hospital, the Center offers the use of its facilities to some of the top neurosurgeons and radiation oncologists in Southern California. It’s also a proud partner of the Neurosciences Department of Scripps Memorial Hospital La Jolla, helping to provide accurate diagnoses, treatment and support for a range of neurological conditions and disorders. To learn more about the San Diego Gamma Knife Center®, please visit http://www.sdgkc.com.

Sources:
1.    Sheehan J, et al. Gamma Knife radiosurgery for the management of nonfunctioning pituitary adenomas: A multicenter study. Journal of Neurosurgery. 2013;119:446. http://thejns.org/doi/full/10.3171/2013.3.JNS12766. Accessed June 20, 2017.
2.    What Are the Key Statistics About Pituitary Tumors? American Cancer Society. https://www.cancer.org/cancer/pituitary-tumors/about/key-statistics.html. Accessed June 20, 2017.
3.    What Are Pituitary Tumors? American Cancer Society. https://www.cancer.org/cancer/pituitary-tumors/about/what-is-pituitary-tumor.html. Accessed June 20, 2017.
4.    Radiation—Gamma Knife Radiosurgery for Pituitary Adenomas. Pituitary Network Association. https://pituitary.org/medical-resources/pavilions/diagnostics-scanning-and-radiological-pavilion/diagnostics-scanning-and-radiological-archive/radiation-gamma-knife-radiosurgery-for-pituitary-adenomas. Accessed June 20, 2017.
5.    Gamma Knife Radiation Therapy for Pituitary Tumors—Candidates for Gamma Knife Treatment. The Pituitary Society. http://pituitarysociety.org/patient-education/pituitary-disorders/gammaradiation/candidates. Accessed June 20, 2017.
6.    Lee C, et al. Initial Gamma Knife radiosurgery for nonfunctioning pituitary adenomas. Journal of Neurosurgery. 2014;120:647. http://thejns.org/doi/full/10.3171/2013.11.JNS131757. Accessed June 20, 2017.
7.    Gamma Knife Radiosurgery Safe in Early Pituitary Tumor. Medscape. http://www.medscape.com/viewarticle/879250. Accessed June 20, 2017.

For the original version on PRWeb visit: http://www.prweb.com/releases/2017/07/prweb14478413.htm

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