Intraoperative MRI improves complete resection of pituitary macroadenoma

A 63-year-old man was referred to the Massachusetts General Hospital Neuroendocrine & Pituitary Tumor Clinical Center for management of a pituitary macroadenoma. He experienced increasingly severe retro-orbital headaches in the past year. He reported no double vision, fatigue, orthostatic dizziness, change in beard growth or reduction in libido. An outside head CT scan showed an enlarged pituitary gland.

Imaging and laboratory tests

A pituitary MRI with magnified pituitary slices and gadolinium contrast was ordered. A well-circumscribed “snowman-shaped” sellar mass was identified, measuring 2.6 cm x 2 cm x 1.8 cm (anteroposterior x transverse x craniocaudal) with suprasellar extension (Figure 1). The lesion was heterogeneous on T1-weighted scans after enhancement with IV gadolinium contrast. An area of hypointensity in the superior margin was consistent with a small area of cystic or hemorrhagic degeneration.

Although the mass did not extend laterally into the cavernous sinus, the sellar mass extended upward into the suprasellar cistern through a hole in the dural, the diaphragma sellae, to compress the optic chiasm. The restriction of adenoma growth by the diaphragma sellae results in the snowman shape of the macroadenoma. The optic chiasm and infundibulum (pituitary stalk) could not be identified on coronal or sagittal images (Figure 1). Visual field on confrontation suggested lateral field deficits (bilateral lateral hemianopsia) that were confirmed on formal Goldmann kinetic perimetry visual fields.

Figure 1. Preoperative MRI scan. A large “snowman-shaped” pituitary adenoma (green arrow) has heterogeneous enhancement after gadolinium contrast administration. A small hypodense area in the adenoma likely represented hemorrhage/cystic degeneration (yellow arrow). The tumor does not surround the carotid siphon, an S-shaped portion of the internal carotid artery (red arrows) within the cavernous sinus located laterally from the sella turcica where the pituitary gland resides. (A) Coronal image. (B) Sagittal image. Abbreviation: SS = spenoid sinus.

Source: Stephanie L. Lee, MD, PhD, ECNU. Reprinted with permission.

Initial hormonal evaluation was normal and included morning adrenocorticotropic hormone 18 pg/mL, cortisol 13.64 µg/dL, thyroid-stimulating hormone 2.14 uIU/mL, free thyroxine 1.2 ng/dL and prolactin 12.6 ng/mL. The patient’s morning testosterone level was normal at 324 ng/dL, with follicle-stimulating hormone 2.4 mIU/mL and luteinizing hormone 1.6 mIU/mL. His insulin-like growth factor I level was normal at 124 ng/mL.

Tumor resection

The patient was treated preoperatively with stress-dose hydrocortisone 50 mg. He then underwent transsphenoidal pituitary tumor resection. After the surgeon believed there was an adequate excision of the tumor, the extent of tumor resection was confirmed by an intraoperative MRI (Figure 2 on page 8).

Figure 2. Intraoperative MRI scan. The large macroadenoma is not seen after transsphenoidal surgery. The optic chiasm (yellow arrow) can be seen after removal of the tumor. (A) Coronal image. (B) Sagittal image. Abbreviation: SS = spenoid sinus.

The operation was concluded after the imaging confirmed the complete resection of the pituitary adenoma. The patient’s postoperative course was uneventful. Imaging 4 weeks after the resection confirmed complete resection of the suprasellar mass with residual enhancement of the resection bed and sphenoid sinuses (Figure 3 on page 8). The postoperative MRI revealed a normal optical chiasm and a downward tending of the infundibulum to the residual pituitary gland located inferiorly along the sella turcica (pituitary fossa) of the sphenoid bone. Pathology confirmed a pituitary adenoma. His anterior and posterior pituitary function were normal 6 weeks postoperatively, and his visual field deficit improved.

Intraoperative MRI

Imaging like that used in this case occurs in a specially designed operating room that allows MRI scans during surgery without moving the patient from the surgical table. The MRI is kept in a shielded enclosure during the procedure and then moved along a track into the operating room for imaging. Clinical indications for the use of intraoperative MRI in neurosurgery include resection of pituitary macroadenomas. In the past, these tumors underwent transsphenoidal resection, and the postoperative MRI was performed after 1 or more days after the procedure to check for complete removal. If residual tumor was found, the patients underwent watchful waiting, external radiation or repeat surgery.

The strategic advantage of an intraoperative MRI is that the imaging is performed during the operative procedure, and if there is any residual tumor, surgery can be resumed after the MRI is moved back into the shielded enclosure.

Figure 3. Four-week postoperative MRI scan. The large macroadenoma is not seen after the transsphenoidal survey. The optic chiasm and infundibulum (pituitary stalk) can be seen after resection of the tumor. The pituitary stalk is deviated to the left of the sella where the residual normal thyroid is locate along the sella turcica. The floor of the sella enhances with gadolinium infusion after surgery due to postoperative inflammation. (A) Coronal image. (B) Sagittal image. Abbreviation: SS = spenoid sinus.

It has been reported that the use of intraoperative MRI does not increase complication rates compared with conventional transsphenoidal surgery. Reports on the improvement of gross tumor resection using intraoperative MRI are variable, perhaps due to the expertise of the surgeon. Several reports suggest the use of intraoperative MRI allowed additional resection of noninvasive macroadenomas in 67% to 83% of the patients with a gross tumor resection. These results suggest that a substantial volume reduction and increased gross tumor resection of pituitary macroadenomas occurs with the use of intraoperative MRI compared with standard surgery. One study demonstrated that the gross tumor resection rates of invasive tumors was also improved with the use of intraoperative MRI compared with usual preoperative imaging and surgery (25% vs. 7%).

The use of intraoperative MRI, especially with transsphenoidal reoperations for invasive and noninvasive pituitary macroadenomas, leads to significantly higher “gross tumor resection” rates. This method prevents additional operations or treatment, such as radiation, because it reduces the number of patients with residual adenoma after surgery. This technology is usually found in specialized tertiary care hospitals but should be considered for reoperation for large pituitary macroadenomas or initial operation for large invasive pituitary macroadenomas.

Disclosures: Lee and Swearingen report no relevant financial disclosures.

From https://www.healio.com/endocrinology/neuroendocrinology/news/print/endocrine-today/%7B23183444-4d29-477b-844f-6eb995ac74f4%7D/intraoperative-mri-improves-complete-resection-of-pituitary-macroadenoma

Experimental Drug Improves Cushing’s Disease

International phase 3 trial is largest study ever of rare endocrine disorder

A new investigational drug significantly reduced urinary cortisol levels and improved symptoms of Cushing’s disease in the largest clinical study of this endocrine disorder ever conducted.

Results of the clinical trial conducted at centers on four continents appear in the March 8 issue of the New England Journal of Medicine and show that treatment with pasireotide cut cortisol secretion an average of 50 percent and returned some patients’ levels to normal.

“Cushing’s disease is a rare disorder, with three to five cases per million people. It can affect all ages and both genders but is most common in otherwise healthy young women,” says Harvard Medical School Professor of Medicine Beverly M.K. Biller of the Massachusetts General Hospital (MGH) Neuroendocrine Unit, senior author of the study.

“Often misdiagnosed, Cushing’s is associated with a broad range of health problems – causing physical changes, metabolic abnormalities, and emotional difficulties – and if not controlled, significantly increases patients’ risk of dying much younger than expected,” Biller says.

Cushing’s disease, one of several conditions that lead to Cushing’s syndrome, is characterized by chronically elevated secretion of the hormone cortisol. The disease is caused by a benign pituitary tumor that oversecretes the hormone ACTH, which in turn induces increased cortisol secretion by the adrenal glands.

Symptoms of Cushing’s syndrome include weight gain, hypertension, mood swings, irregular or absent periods, abnormalities of glucose processing (insulin resistance, glucose intolerance, and type 2 diabetes), and cardiovascular disease. Because those symptoms are associated with many health problems, physicians may not consider the rare possibility of Cushing’s. The diagnosis can be difficult to make and usually requires the expertise of an endocrinologist. Because cortisol levels normally fluctuate during the day, a single blood test is unlikely to identify chronic elevation, and thus the most common diagnostic test measures a patient’s 24-hour urinary output.

First-line treatment for Cushing’s disease is surgical removal of the ACTH-secreting tumor, which leads to remission in 65 to 90 percent of patients. But symptoms return in 10 to 30 percent of those patients, requiring repeat surgery, radiation therapy, or treatment with drugs that interfere with part of the cortisol control system. Until last month, there was no specific FDA-approved medical treatment for Cushing’s syndrome; the newly approved drug mifepristone should benefit some patients, but it does not affect the pituitary source of the condition or reduce cortisol levels.

The current phase 3 trial of pasireotide — the first drug that blocks ACTH secretion by binding to somatostatin receptors on the pituitary tumor — was sponsored by Novartis Pharma. The trial enrolled 162 patients at 62 sites in 18 countries. Nearly 85 percent of participants had either persistent disease that had not responded to surgery or had recurrent disease; the other 15 percent were recently diagnosed but not appropriate candidates for surgery.

Participants were randomly assigned to two groups, one starting at two daily 600-microgram injections of pasireotide and the other receiving 900-microgram doses. Three months into the 12-month trial, participants whose urinary cortisol levels remained more than twice the normal range had their dosage levels increased. During the rest of the trial, dosage could be further increased, if necessary, or reduced if side effects occurred.

At the end of the study period, many patients had a significant decrease in their urinary cortisol levels, with 33 achieving levels within normal range at their original dosage by month six of the trial. Participants whose baseline levels were less than five times the upper limit of normal were more likely to achieve normal levels than those with higher baseline levels, and the average urinary cortisol decrease across all participants was approximately 50 percent. Many Cushing’s disease symptoms decreased, and it became apparent within the first two months whether or not an individual was going to respond to pasireotide.

Transient gastrointestinal discomfort, known to be associated with medications in the same family as pasireotide, was an expected side effect. Another side effect was elevated glucose levels in 73 percent of participants, something not seen to the same extent with other medications in this family. These elevated levels will require close attention, because many Cushing’s patients already have trouble metabolizing glucose. Biller explains, “Those patients who already were diabetic had the greatest increases in blood sugar, and those who were pre-diabetic were more likely to become diabetic than those who began with normal blood sugar. However, elevations were even seen in those who started at normal glucose levels, so this is real and needs to be monitored carefully.”

Additional trials of pasireotide are in the works, and a phase 3 study of a long-acting version of the drug was recently announced. Biller notes that the potential addition of pasireotide to available medical treatments for Cushing’s disease would have a number of advantages. “It’s very important to have medications that work at different parts of the cortisol control system – which is the case for the currently used medications that work at the adrenal gland level; pasireotide, which works at the pituitary gland; and mifepristone, which blocks the action of cortisol at receptors in the body. Having more options that work in different ways is valuable because not all patients respond to one medicine and some may be unable to tolerate a specific drug’s side effects.

“As we have more drugs available to treat Cushing’s,” Biller adds, “I think in the long run we may start using combinations of drugs, which is the approach we use in some patients with acromegaly, another disorder in which a pituitary tumor causes excess hormone secretion. Ultimately, we hope to be able to give lower doses leading to fewer overall side effects, but that remains to be determined by future studies.”

Annamaria Colao, University of Naples, Italy, is the lead author of the report. Additional co-authors are Stephan Petersenn, University of Duisberg-Essen, Germany; John Newell-Price, University of Sheffield, U.K.; James Findling, Medical College of Wisconsin, Milwaukee; Feng Gu, Peking Union Medical College Hospital, Beijing; Mario Maldonado, Ulrike Schoenherr, and David Mills, Novartis Pharma; and Luiz Roberto Salgado, University of São Paulo Medical School, Brazil.

From http://dailyrecords.us/experimental-drug-improves-cushings-disease/

Webinar: Diagnosis and Management of Acromegaly: A Clinical Update

Presented by
Lisa Nachtigall, MD
Co-director Neuroendocrine Clinical Center
Massachusetts General Hospital

Register Here

After registering you will receive a confirmation email with details about joining the webinar.

Contact us at webinar@pituitary.org with any questions or suggestions.

Date: Monday, July 27, 2015
Time: 2:00 PM – 3:00 PM Pacific Daylight Time

Presenter Bio
Lisa B. Nachtigall, MD, is an Associate Professor of Medicine at Harvard Medical School, the clinical co-director of the Neuroendocrine Clinical Center at Massachusetts General Hospital and course director in Clinical Neuroendocrine at Harvard Medical School.

Dr. Nachtigall earned her medical degree from New York University (NYU) School of Medicine in New York City. She completed her internship and residency in internal medicine at Bellevue Hospital Center/NYU school of Medicine, and a clinical fellowship in endocrinology and metabolism, as well as a research fellowship in reproductive endocrinology at Massachusetts General Hospital/Harvard Medical School.

Dr. Nachtigall’s work has been published in the New England Journal of Medicine, the Journal of Clinical Endocrinology and Metabolism, Neurosurgery, Pituitary, and the Clinical Endocrinology among others. She serves on the editorial board of Pituitary and as an ad hoc reviewer for many endocrine journals. Dr Nachtigall has been a presenter at national and international medical conferences, and she is currently an investigator on several clinical studies of acromegaly and pituitary tumors.

%d bloggers like this: