Pituitary Adenoma Incidence, Management Trends, and Long-term Outcomes: A 30-Year Population-Based Analysis.

OBJECTIVE: To perform a population-based study of pituitary adenoma epidemiology, including longitudinal trends in disease incidence, treatment patterns, and outcomes. PATIENTS AND METHODS: In this study of incident pituitary adenomas in Olmsted County, Minnesota, from January 1, 1989, through December 31, 2019, we identified 785 patients who underwent primary screening, 435 of whom were confirmed as harboring incident pituitary adenomas and were included. Primary outcomes of interest included demographic characteristics, presenting features, and disease outcomes (tumor control, biochemical control, and complications). RESULTS: Among our 435 study patients, 438 unique pituitary adenomas were diagnosed at a median patient age of 39 years (interquartile range [IQR], 27 to 58 years). Adenomas were incidentally identified in 164 of the 438 tumors (37%). Common symptomatic presentations included hyperprolactinemia (188 of 438 [43%]) and visual field deficit (47 of 438 [11%]). Laboratory tests confirmed pituitary hormone hypersecretion in 238 of the 435 patients (55%), which was symptomatic in 222. The median tumor diameter was 8 mm (IQR, 5 to 17 mm). Primary management strategies were observation (156 of 438 tumors [36%]), medication (162 of 438 tumors [37%]), and transsphenoidal resection (120 of 438 tumors [27%]). Tumor and biochemical control were achieved in 398 (95%) and 216 (91%) secreting tumors, respectively. New posttreatment pituitary or visual deficits were noted in 43 (11%) and 8 (2%); apoplexy occurred in 28 (6%). Median clinical follow-up was 98 months (IQR, 47 to 189 months). Standardized incidence rates were 3.77 to 16.87 per 100,000 population, demonstrating linear expansion over time (R2=0.67). The mean overall standardized incidence rate was 10.1 per 100,000 population; final point prevalence was 175.1 per 100,000 population. CONCLUSION: Pituitary adenoma is a highly incident disease, with prolactin-secreting and incidental lesions representing the majority of tumors. Incidence rates and asymptomatic detection appear to be increasing over time. Presenting symptoms and treatment pathways are variable; however, most patients achieve favorable outcomes with observation or a single treatment modality.

Brain metastases resection cavity radio-surgery based on T2-weighted MRI: technique assessment.

PURPOSE: Stereotactic radiosurgery (SRS) is commonly performed after surgical resection of brain metastases to reduce the chance of local tumor recurrence while maintaining cognitive function. Target delineation in these cases is typically based off T1-weighted post-gadolinium MRI (T1Gd). In this study, we report outcomes for patients having postoperative SRS in which the planning target volume (PTV) was based on T2-weighted MRI (T2W). METHODS: Sixty-two consecutive patients having single-fraction SRS after brain metastases resection were retrospectively reviewed. Excluded were patients with prior whole brain radiation therapy, multiple resection cavities, and small cell pathologies. RESULTS: The median time from surgery to SRS was 11 days; 26 patients (42%) had SRS ≤ 7 days. The median PTV was 8.0 cm3; the median margin dose was 18 Gy. The crude rates of local tumor control (LC), leptomeningeal disease (LMD), distant brain recurrence (DBR), and radiation necrosis (RN) were 85%, 19%, 37%, and 2%, respectively. The 1-year LC, LMD, DBR, and RN rates were 88%, 25%, 36%, and 0%, respectively. No tumor or dosimetric factor was associated with LC. Sub-total tumor resection was a risk factor for LMD (HR 5.11, P = 0.003), whereas patients with multiple brain metastases had a greater risk of DBR (HR 2.88, P = 0.01). The median PTV was smaller compared to the median PTV based off the consensus guidelines utilizing T1Gd MRI (8.0 cm3 vs. 9.1 cm3, P = 0.004). CONCLUSION: T2W MRI provided accurate resection cavity delineation even in the early postoperative period and was associated with decreased PTV compared to T1Gd MRI in the majority of cases.

Incidence and Management of Late Adverse Radiation Effects After Arteriovenous Malformation Radiosurgery.

BACKGROUND: Late adverse radiation effects (ARE) typically occur many years after stereotactic radiosurgery (SRS) of intracranial arteriovenous malformations (AVM). They are characterized by perilesional edema or cyst formation and are distinct from radiation-induced changes (RIC) noted in the first 1 to 2 years after AVM SRS and radiation necrosis. OBJECTIVE: To determine the incidence of late ARE after AVM SRS. METHODS: Retrospective review of 233 AVM patients having SRS from 1990 to 2009. Patients had sporadic AVM, no prior radiation, and a minimum of 5 years of magnetic resonance imaging (MRI) follow-up. The median MRI follow-up after SRS was 9.8 years (range, 5-24.2). RESULTS: Late ARE were observed in 16 patients (6.9%) at a median of 8.7 years after SRS (range, 2.0-16.1). The 5-, 10-, and 15-year incidence of late ARE was 0.4%, 7.7%, and 12.5%, respectively. Eight patients (3.4%) were symptomatic at the time of ARE detection. Three of 8 patients who were initially asymptomatic had documented cyst progression (at 11, 40, and 42 months), for an overall symptomatic rate of 4.7%. Five patients with asymptomatic ARE have been observed for a median of 9.3 years (range, 2.0-14.1) without progression. Patients having early RIC (hazard ratio [HR] = 2.11, P < .001), patients having obliteration (HR = 1.24, P = .02), and patients having SRS before April 1997 (HR = 1.12, P = .02) were more likely to develop late ARE. CONCLUSION: Late ARE are common in AVM patients who develop early RIC after SRS. Resection of the thrombosed AVM and the adjacent damaged tissue is effective at eliminating the mass effect and improving patients' neurological condition.

Comparison of the surgical and follow-up costs associated with microsurgical resection and stereotactic radiosurgery for vestibular schwannoma.

OBJECT: The best approach to the management of vestibular schwannoma (VS) remains controversial. The aim of this study is to analyze the initial and follow-up costs of resection and stereotactic radiosurgery for patients with VS. METHODS: Initial and follow-up costs in 53 cases in which patients with unilateral, previously unoperated VSs > 3 cm underwent resection (21 cases) or radiosurgery (32 cases) at the Mayo Clinic from June 2000 until July 2002 were analyzed for 36 months. Follow-up treatment-specific utilization records were gathered prospectively for patients not returning to the Mayo Clinic after treatment. Six-month moving averages of incremental follow-up costs were calculated for the 2 patient groups. RESULTS: The mean cost of surgery in the microsurgery group was $23,788 (95% confidence interval $22,280-$24,842) compared with $16,143 (95% confidence interval $15,277-$17,545) for the radiosurgical group. Mean incremental follow-up costs per month for patients in the microsurgery group started just > $1,000 per month, decreased steadily, and remained < $70 per month by the 10th month of follow-up. Mean incremental follow-up costs per month for patients in the radiosurgery group were <$10 per month for the first few months and thereafter increased to as much as $200 per month. CONCLUSIONS: Although the total cost of microsurgery is higher due to the costs of hospitalization, follow-up costs for radiosurgery are greater in general. From a societal perspective, radiosurgery is less expensive than microsurgical resection provided that the rate of tumor progression after radiosurgery remains low with long-term follow-up.

A prospective cost-effectiveness study of trigeminal neuralgia surgery.

OBJECTIVES: Approximately 8000 patients with trigeminal neuralgia undergo surgery each year in the United States at an estimated cost exceeding $100 million. We compared 3 commonly performed surgeries (microvascular decompression, glycerol rhizotomy, and stereotactic radiosurgery) to evaluate the relative cost-effectiveness of these operations for patients with idiopathic trigeminal neuralgia. METHODS: Prospective nonrandomized trial at a tertiary referral center from July 1999 to December 2001. One hundred twenty-six consecutive patients underwent 153 operations (microvascular decompression, n=33; glycerol rhizotomy, n=51; stereotactic radiosurgery, n=69). Preoperative characteristics were similar between the groups with respect to sex, pain location, duration of pain, and atypical features. Facial pain outcomes were classified as excellent (no pain, no medications), good (no pain, reduced medications), fair (>50% pain reduction), and poor. The cost per quality adjusted pain-free year was compared between the groups. Mean follow-up was 20.6 months. RESULTS: Patients having microvascular decompression more commonly achieved and maintained an excellent outcome (85% and 78% at 6 and 24 months) compared with glycerol rhizotomy (61% and 55%, P=0.01) and stereotactic radiosurgery (60% and 52%, P<0.01). No difference was detected between glycerol rhizotomy and stereotactic radiosurgery (P=0.61). The cost per quality adjusted pain-free year was $6,342, $8,174, and $8,269 for glycerol rhizotomy, microvascular decompression, and stereotactic radiosurgery, respectively. Reduction in the average cost of morbidity and additional surgeries to zero did not make either microvascular decompression or stereotactic radiosurgery more cost-effective than glycerol rhizotomy. Both microvascular decompression and stereotactic radiosurgery would be more cost-effective than glycerol rhizotomy if the cost of additional surgeries after glycerol rhizotomy increased 79% and 83%, respectively. DISCUSSION: This analysis supports the practice of percutaneous surgeries for older patients with medically unresponsive trigeminal neuralgia. At longer follow-up intervals, microvascular decompression is predicted to be the most cost-effective surgery and should be considered the preferred operation for patients if their risk for general anesthesia is acceptable. More data are needed to assess the role that radiosurgery should play in the management of patients with trigeminal neuralgia.