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Martin J. Rutkowski, Sandeep Kunwar, Lewis Blevins, and Manish K. Aghi

OBJECTIVE

Pituitary apoplexy is a clinical syndrome consisting of neurological and endocrine abnormalities secondary to hemorrhage or ischemia of an underlying pituitary adenoma. The authors investigated whether there was a significant difference in neurological, endocrine, and nonneuroendocrine outcomes for patients with pituitary apoplexy, based on the time between symptom onset and surgical intervention.

METHODS

The authors retrospectively analyzed the medical records of 32 patients who had presented to their institution with acute pituitary apoplexy and subsequently undergone endonasal transsphenoidal resection in the period from 2003 to 2014. All patients had undergone preoperative MRI demonstrating evidence of apoplexy in the form of intratumoral hemorrhage, ischemia, and necrosis. Neurological deficits, partial or complete endocrinopathy, and nonneuroendocrine abnormalities were analyzed both pre- and postoperatively.

RESULTS

Preoperatively, neurological deficits including visual loss and cranial nerve palsies were found in 31 (97%) of the 32 patients, endocrinopathy in the form of partial or panhypopituitarism was seen in 28 patients (88%), and nonneuroendocrine signs and symptoms were seen in 32 patients (100%). Thirteen patients (41%) underwent surgery within 72 hours of symptom onset (“early”), whereas 19 patients (59%) underwent surgery more than 72 hours from symptom onset (“delayed”). Early versus delayed resection did not appear to significantly improve visual deficits, total visual loss, resolution of oculomotor palsy, recovery from hypopituitarism, or nonneuroendocrine signs and symptoms such as headache and encephalopathy. Overall, visual improvement was seen in 77% of patients, complete restoration of normal vision in 38% of patients, and resolution of preoperative oculomotor palsies in 81% of patients. Only 6 (21%) of 28 patients showed evidence of partial hormone recovery following preoperative hypopituitarism. An absence of benefit for early surgery held true even when considering time to surgery from symptom onset as a continuous variable.

CONCLUSIONS

Neurological deficits such as visual loss and cranial neuropathies show moderate improvement following surgical decompression, as does preoperative hypopituitarism. The timing of surgical intervention relative to the onset of symptoms does not appear to significantly affect the resolution of neurological or endocrinological deficits.

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Sandeep Kunwar, Lee H. Pai, and Ira Pastan

✓ The prognosis of glioblastoma multiforme remains poor despite advances in treatment by surgery, irradiation, and chemotherapy. Many malignant gliomas overexpress growth factor receptors. The possibility of targeting these receptors with selective cytotoxic molecules constructed by fusing deoxyribonucleic acid (DNA)-encoding mutant forms of Pseudomonas exotoxin A (PE) with complementary DNA-encoding growth factors was investigated. Several recombinant toxins have been produced, including those in which transforming growth factor (TGF)-α, insulin-like growth factor (IGF)-I and acidic fibroblast growth factor (FGF) were fused to mutant forms of PE lacking the native cell-binding domain. These recombinant proteins are cytotoxic to cells that express specific cell-surface receptors. The cytotoxic activity of TGF-α, IGF-I, and acidic FGF chimeric toxins was tested in vitro against human glioblastoma cell lines. Each recombinant toxin exhibited potent and specific killing of cells. The TGF-α-PE40 construct was cytotoxic to seven of the eight cell lines and was active at concentrations as low as 0.5 ng/ml (1.1 × 10−11 M). The acidic FGF-PE40 toxin was also active on seven of the eight cell lines but was 50-fold less active than the TGF-α-PE40. The IGF-I-PE40 construct was active on only two cell lines. To determine the possible therapeutic effect in animals, TGF-α-PE40 was administered to nude mice bearing subcutaneous human glioblastoma xenografts. The animals were treated for 7 days via a continuous infusion pump placed in the peritoneal cavity. A constant serum level of TGF-α-PE40 was achieved that was nontoxic to the mice yet caused a reduction in tumor volume and retarded growth beyond the treatment period. The overexpression of the epidermal growth factor receptor in glioblastomas multiforme and the potency and specificity of the TGF-α-PE40 construct designed to target this receptor suggests that TGF-α-PE40 has the potential to be an effective antitumor agent for the adjuvant therapy of these carcinomas.

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Paula L. Petti, David A. Larson, and Sandeep Kunwar

Object

The authors investigated the use of different collimator values in different sectors (hybrid shots) when treating patients with lesions close to critical structures with the Perfexion model Gamma Knife.

Methods

Twelve patients with various tumors (6 with a pituitary tumor, 3 with vestibular schwannoma, 2 with meningioma, and 1 with metastatic lesion) that were within 4 mm of the brainstem, optic nerve, pituitary stalk, or cochlea were considered. All patients were treated at the authors' institution between June 2007 and March 2008. The patients' treatments were replanned in 2 different ways. In the first plan, hybrid shots were used such that the steepest dose gradient was aligned with the junction between the target and the critical structure(s). This was accomplished by placing low-value collimators in appropriate sectors. In the second plan, no hybrid shots were used. Sector blocking (either manual or dynamic) was required for all plans to reduce the critical structure doses to acceptable levels. Prescribed doses ranged from 12 to 30 Gy at the periphery of the target. The plans in each pair were designed to be equally conformal in terms of both target coverage (as measured by the Paddick conformity index) and critical structure sparing.

Results

The average number of shots required was roughly the same using either planning technique (16.7 vs 16.6 shots with and without hybrids). However, for all patients, the number of blocked sectors required to protect critical areas was larger when hybrid shots were not used. On average, nearly twice as many blocked sectors (14.8 vs 7.0) were required for the plans that did not use hybrid shots. The number of high-value collimators used in each plan was also evaluated. For small targets (≤ 1 cm3), for which 8 mm was considered a high value for the collimator, plans employing hybrids used an average of 2.3 times as many 8-mm sectors as did their nonhybrid counterparts (7.4 vs 3.2 sectors). For large targets (> 1 cm3), for which 16 mm was considered a high value for the collimator, hybrid plans used an average of 1.4 times as many 16-mm sectors as did the plans without hybrids (10.7 vs 7.7 sectors). Decreasing the number of blocked sectors and increasing the number of high-value collimator sectors led to use of shorter beam-on times. Beam-on times were 1–39% higher (average 17%) when hybrid shots were not allowed. The average beam-on time for plans with and without hybrid shots was 67.4 versus 78.4 minutes.

Conclusions

The judicious use of hybrid shots in patients for whom the target is close to a critical structure is an efficient way to achieve conformal treatments while minimizing the beam-on time. The reduction in beam-on time with hybrid shots is attributed to a reduced use of blocked sectors and an increased number of high-value collimator sectors.

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Arman Jahangiri, Kathleen R. Lamborn, Lewis Blevins, Sandeep Kunwar, and Manish K. Aghi

Object

The duration of visual symptoms associated with a nonfunctioning pituitary adenoma (NFA) is a predictive factor for chances of visual improvement. The authors investigated factors associated with increased duration of visual symptoms in patients with NFAs.

Methods

The authors retrospectively reviewed NFAs resected at their institution between 2004 and 2010 for duration of visual symptoms, postoperative improvement, and associated factors.

Results

Seventy-five patients underwent NFA resection with a median visual symptom duration of 6.5 months (range 1 week–15 years). A multivariate logistic regression showed that duration of symptoms (p = 0.04), but not age at surgery (p = 0.2), predicted postoperative normalization of vision. Univariate nonparametric analyses investigating age at symptom onset, sex, race, insurance type, ophthalmological conditions, income, marital status, emergency department admission, language, and medical provider found that age was the only variable significantly prolonging symptom duration (p = 0.04), a finding confirmed by a multivariate regression analysis. Patients 20–39, 40–59, and 60–79 years old had median durations of symptoms of 4, 7, and 9 months, respectively. Seven older patients had symptoms attributed to preexisting ophthalmological conditions for a median of 18 months before NFA diagnosis. Among age and race subgroups, the largest difference in median symptom duration was between white patients in the 60–79-year age range (duration of 5 months) and nonwhite patients in the 60–79-year age range (duration of 24 months) (p = 0.04).

Conclusions

The authors found that older age was associated with delayed NFA diagnosis in visually impaired patients. Contributing factors were the attributing of visual symptoms from NFAs to other ophthalmological conditions in these patients, and delayed presentation in elderly nonwhite patients. These findings highlight challenges associated with timely NFA diagnosis in visually impaired patients, a key factor for chances of improvement.

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Jonathan Rick, Arman Jahangiri, Patrick M. Flanigan, Ankush Chandra, Sandeep Kunwar, Lewis Blevins, and Manish K. Aghi

OBJECTIVE

Acromegaly results in disfiguring growth and numerous medical complications. This disease is typically caused by growth hormone (GH)–secreting pituitary adenomas, which are treated first by resection, followed by radiation and/or medical therapy if needed. A subset of acromegalics have dual-staining pituitary adenomas (DSPAs), which stain for GH and prolactin. Presentations and treatment outcomes for acromegalics with DSPAs are not well understood.

METHODS

The authors retrospectively reviewed the records of more than 5 years of pituitary adenomas resected at their institution. Data were collected on variables related to clinical presentation, tumor pathology, radiological size, and disease recurrence. The Fisher’s exact test, ANOVA, Student t-test, chi-square test, and Cox proportional hazards and multiple logistic regression were used to measure statistical significance.

RESULTS

Of 593 patients with pituitary adenoma, 91 presented with acromegaly. Of these 91 patients, 69 (76%) had tumors that stained for GH only (single-staining somatotrophic adenomas [SSAs]), while 22 (24%) had tumors that stained for GH and prolactin (DSPAs). Patients with DSPAs were more likely to present with decreased libido (p = 0.012), signs of acromegalic growth (p = 0.0001), hyperhidrosis (p = 0.0001), and headaches (p = 0.043) than patients with SSAs. DSPAs presented with significantly higher serum prolactin (60.7 vs 10.0 µg/L, p = 0.0002) and insulin-like growth factor-1 (IGF-1) (803.6 vs 480.0 ng/ml, p = 0.0001), and were more likely to have IGF-1 levels > 650 ng/ml (n = 13 [81.3%] vs n = 6 [21.4%], p = 0.0001) than patients with SSAs despite similar sizes (1.8 vs 1.7 cm, p = 0.5). Patients with DSPAs under 35 years of age were more likely to have a recurrence (n = 4 [50.0%] vs n = 3 [11.1%], p = 0.01) than patients with SSAs under the age of 35. DSPA patients were less likely to achieve remission with surgery than SSA patients (n = 2 [20%] vs n = 19 [68%], p = 0.01). Univariate analysis identified single-staining tumors (p = 0.02), gross-total resection (p = 0.02), and tumor diameter (p = 0.05) as predictors of surgical remission. Multiple logistic regression demonstrated that SSAs (p = 0.04) were independently associated with surgical remission of acromegaly. Kaplan-Meier analysis revealed that DSPAs had more time until disease remission (p = 0.033).

CONCLUSIONS

Acromegalics with tumors that stain for prolactin and GH, which represented almost a quarter of acromegalics in this cohort, had more aggressive clinical presentations and postoperative outcomes than SSAs. Prolactin staining provides useful information for acromegalics undergoing pituitary surgery.

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John H. Sampson, Gamal Akabani, Allan H. Friedman, Darell Bigner, Sandeep Kunwar, Mitchel S. Berger, and Krystof S. Bankiewicz

Objectives

Convection-enhanced delivery (CED) is a novel technique used to deliver agents to the brain parenchyma for treatment of neoplastic, infectious, and degenerative conditions. The purpose of this study was to determine if CED would provide a larger volume of distribution (Vd) of a radiolabeled monoclonal antibody (mAb) than a bolus injection.

Methods

Patients harboring a recurrent glioblastoma multiforme that reacted with the antitenascin mAb 81C6 during immunohistochemical analysis were randomized to receive an intratumoral injection of the human–murine chimeric mAb Ch81C6, which had been labeled with the 123I tracer. The mAb was administered by either a bolus injection or CED via a stereotactically placed catheter; between 48 and 72 hours later the mAb was again administered using the other technique. Injections of escalating doses of a 131I-labeled therapeutic mAb were then delivered using the technique shown to produce the largest Vd by single-photon emission computerized tomography.

Conclusions

Convection-enhanced delivery has enormous potential for administering drugs to sites within the central nervous system. For the relatively small volumes injected in this study, however, CED did not provide a significant increase in the Vd when compared with the bolus injection. Nevertheless, a clear cross-over effect was seen, which was probably related to the temporal proximity of the two infusions.

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Arman Jahangiri, Aaron J. Clark, Seunggu J. Han, Sandeep Kunwar, Lewis S. Blevins Jr., and Manish K. Aghi

Object

Pituitary apoplexy is associated with worse outcomes than are pituitary adenomas detected without acute clinical deterioration. The association between pituitary apoplexy and socioeconomic factors that may limit access to health care has not been examined in prior studies.

Methods

This study involved retrospectively evaluating data obtained in all patients who underwent surgery for nonfunctioning pituitary adenoma causing visual symptoms between January 2003 and July 2012 at the University of California, San Francisco. Patients were grouped into those who presented with apoplexy and those who did not (“no apoplexy”). The 2 groups were compared with respect to annual household income, employment status, health insurance status, and whether or not the patient had a primary health care provider. Associations between categorical variables were analyzed by chi-square test and continuous variables by Student t-test. Multivariate logistic regression was also performed.

Results

One hundred thirty-five patients were identified, 18 of whom presented with apoplexy. There were significantly more unmarried patients and emergency room presentations in the apoplexy group than in the “no apoplexy” group. There was a nonsignificant trend toward lower mean household income in the apoplexy group. Lack of health insurance and lack of a primary health care provider were both highly significantly associated with apoplexy. In a multivariate analysis including marital status, emergency room presentation, income, insurance status, and primary health care provider status as variables, lack of insurance remained associated with apoplexy (OR 11.6; 95% CI 1.9–70.3; p = 0.008).

Conclusions

The data suggest that patients with limited access to health care may be more likely to present with pituitary apoplexy than those with adequate access.

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Phiroz E. Tarapore, Michael E. Sughrue, Lewis Blevins, Kurtis I. Auguste, Nalin Gupta, and Sandeep Kunwar

Object

Pituitary adenomas are uncommon in childhood. Although medical treatment can be effective in treating prolactinomas and some growth hormone (GH)–secreting tumors, resection is indicated when visual function is affected or the side effects of medical therapy are intolerable. The authors of this report describe their 10-year experience in managing pituitary adenomas via the microscopic endonasal transsphenoidal approach in a pediatric population.

Methods

They performed a retrospective review of a surgical case series based at a single institution and consisting of 34 consecutive pediatric patients with endocrine-active (32 patients) and endocrine-inactive (2 patients) adenomas. These patients were surgically treated via an endonasal transsphenoidal approach between 1999 and 2008. Patient charts were reviewed, and clinical data were compiled and analyzed using the chi-square and Kaplan-Meier tests.

Results

The patient cohort consisted of 20 girls and 14 boys, with ages ranging from 9 to 18 years and a median age of 16 years. Thirty-two patients (94%) underwent surgery for endocrine-active tumors, including 10 (29%) with Cushing disease, 21 (62%) with prolactinomas, and 1 (3%) with GH-secreting tumors. Two patients with nonsecreting adenomas underwent surgery for apoplexy. The mean tumor volume was 5.4 cm3, and 13 patients (38%) had suprasellar extension and 7 (21%) had cavernous sinus invasion. Gross-total resection was achieved in 26 patients (76%), although it was significantly less likely to be achieved in the setting of cavernous sinus invasion (p < 0.001) but was unaffected by suprasellar extension. Residual tumor was treated with radiation therapy in 6 patients (18%). The average duration of hospital stay was 1.6 days. The median follow-up time was 18 months. After surgery, 19 patients (56%) had normal hormone function without adjuvant therapy, 8 (24%) had normal function with adjuvant therapy, and 5 (15%) had persistently elevated hormone levels. Patients with a macroprolactinoma were significantly more likely to require postoperative adjuvant therapy than were those with a microprolactinoma (p < 0.03).

Conclusions

Endonasal transsphenoidal resection is a safe, well-tolerated, and potentially curative treatment option for pituitary adenomas in children. Despite the technical challenges associated with this approach in the pediatric population, these tumors can be effectively managed with minimal morbidity. Endocrine function is usually preserved, and the majority of patients will not require lifelong medical therapy.

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Arman Jahangiri, Jeffrey Wagner, Mai T. Tran, Liane M. Miller, Maxwell W. Tom, Sandeep Kunwar, Lewis Blevins Jr., and Manish K. Aghi

Object

Syndrome of inappropriate antidiuretic hormone secretion–induced hyponatremia is a common morbidity after pituitary surgery that can be profoundly symptomatic and cause costly readmissions. The authors calculated the frequency of postoperative hyponatremia after 1045 consecutive operations and determined the efficacy of interventions correcting hyponatremia.

Methods

The authors performed a retrospective review of 1045 consecutive pituitary surgeries in the first 946 patients treated since forming a dedicated pituitary center 5 years ago. Patients underwent preoperative and daily inpatient sodium checks, with outpatient checks as needed.

Results

Thirty-two patients presented with hyponatremia; 41% of these patients were symptomatic. Postoperative hyponatremia occurred after 165 operations (16%) a mean of 4 days after surgery (range 0–28 days); 19% of operations leading to postoperative hyponatremia were associated with postoperative symptoms (38% involved dizziness and 29% involved nausea/vomiting) and 15% involved readmission for a mean of 5 days (range 1–20 days). In a multivariate analysis including lesion size, age, sex, number of prior pituitary surgeries, surgical approach, pathology, lesion location, and preoperative hypopituitarism, only preoperative hypopituitarism predicted postoperative hyponatremia (p = 0.006). Of patients with preoperative hyponatremia, 59% underwent medical correction preoperatively and 56% had persistent postoperative hyponatremia. The mean correction rates were 0.4 mEq/L/hr (no treatment; n = 112), 0.5 mEq/L/hr (free water restriction; n = 24), 0.7 mEq/L/hr (salt tablets; n = 14), 0.3 mEq/L/hr (3% saline; n = 20), 0.7 mEq/L/hr (intravenous vasopressin receptor antagonist Vaprisol; n = 22), and 1.2 mEq/L/hr (oral vasopressin receptor antagonist tolvaptan; n = 9) (p = 0.002, ANOVA). While some patients received more than 1 treatment, correction rates were only recorded when a treatment was given alone.

Conclusions

After 1045 pituitary operations, postoperative hyponatremia was associated exclusively with preoperative hypopituitarism and was most efficiently managed with oral tolvaptan, with several interventions insignificantly different from no treatment. Promptly identifying hyponatremia in high-risk patients and management with agents like tolvaptan can improve safety and decrease readmission. For readmitted patients with severely symptomatic hyponatremia, the intravenous vasopressin receptor antagonist Vaprisol is another treatment option.

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Martin J. Rutkowski, Ryan M. Alward, Rebecca Chen, Jeffrey Wagner, Arman Jahangiri, Derek G. Southwell, Sandeep Kunwar, Lewis Blevins, Han Lee, and Manish K. Aghi

OBJECTIVE

In 2004, the WHO classified atypical pituitary adenoma as a distinct adenoma subtype. However, the clinical significance of this distinction remains undetermined. The authors sought to define patient characteristics, tumor features, and treatment outcomes associated with atypical pituitary adenoma.

METHODS

The authors reviewed records of patients who underwent resection of pituitary adenoma at the University of California, San Francisco, between 2007 and 2014. Per institutional protocol, adenomas exhibiting mitotic activity underwent evaluation for all 3 markers of atypicality (mitotic index, extensive p53 staining, and MIB-1 index ≥ 3%). Statistical analyses were performed using χ2, Fisher’s exact test, t-test, log-rank, and logistic regression.

RESULTS

Between 2007 and 2014, 701 patients underwent resection for pituitary adenoma. Among these patients, 122 adenomas exhibited mitotic activity and therefore were evaluated for all 3 markers of atypicality, with 36 tumors (5%) proving to be atypical. There were 21 female patients (58%) and 15 male patients (42%) in the atypical cohort, and 313 female patients (47%) and 352 male patients (53%) in the nonatypical cohort (p = 0.231). The mean age of patients in the atypical cohort was 37 years (range 10–65 years), which was significantly lower than the mean age of 49 years (range 10–93 years) for patients in the nonatypical cohort (p < 0.001). The most common presenting symptoms for patients with atypical adenomas were headaches (42%) and visual changes (33%). Atypical adenomas were more likely to be functional (78%) than nonatypical adenomas (42%; p < 0.001). Functional atypical adenomas were significantly larger than functional nonatypical adenomas (mean diameter 2.2 vs 1.4 cm; p = 0.009), as were nonfunctional atypical adenomas compared with nonfunctional nonatypical adenomas (mean diameter 3.3 vs 2.3 cm; p = 0.01). Among the entire adenoma cohort, larger presenting tumor size was associated with cavernous sinus invasion (p < 0.001), and subtotal resection was associated with cavernous sinus invasion (p < 0.001) and larger size (p < 0.001) on binomial multivariate regression. The median time until recurrence was 56 months for atypical adenomas, 129 months for functional nonatypical adenomas, and 204 months for nonfunctional nonatypical adenomas (p < 0.001). Functional atypical adenomas recurred more frequently and significantly earlier than functional nonatypical adenomas (p < 0.001). When accounting for extent of resection, cavernous sinus invasion, size, age, sex, and functional subtype, atypicality remained a significant predictor of earlier recurrence among functional adenomas (p = 0.002).

CONCLUSIONS

When compared with nonatypical pituitary adenomas, atypical adenomas are more likely to present in younger patients at a larger size, are more often hormonally hypersecretory, and are associated with earlier recurrence. These features lend credence to atypical pituitary adenomas being a distinct clinical entity in addition to a discrete pathological diagnosis.