Given the neurocognitive toxicity associated with whole-brain irradiation (WBRT), approaches to defer or avoid WBRT after surgical resection of brain metastases are desirable. Our initial experience ...with stereotactic radiosurgery (SRS) targeting the resection cavity showed promising results. We examined the outcomes of postoperative resection cavity SRS to determine the effect of adding a 2-mm margin around the resection cavity on local failure (LF) and toxicity.
We retrospectively evaluated 120 cavities in 112 patients treated from 1998-2009. Factors associated with LF and distant brain failure (DF) were analyzed using competing risks analysis, with death as a competing risk. The overall survival (OS) rate was calculated by the Kaplan-Meier product-limit method; variables associated with OS were evaluated using the Cox proportional hazards and log rank tests.
The 12-month cumulative incidence rates of LF and DF, with death as a competing risk, were 9.5% and 54%, respectively. On univariate analysis, expansion of the cavity with a 2-mm margin was associated with decreased LF; the 12-month cumulative incidence rates of LF with and without margin were 3% and 16%, respectively (P=.042). The 12-month toxicity rates with and without margin were 3% and 8%, respectively (P=.27). On multivariate analysis, melanoma histology (P=.038) and number of brain metastases (P=.0097) were associated with higher DF. The median OS time was 17 months (range, 2-114 months), with a 12-month OS rate of 62%. Overall, WBRT was avoided in 72% of the patients.
Adjuvant SRS targeting the resection cavity of brain metastases results in excellent local control and allows WBRT to be avoided in a majority of patients. A 2-mm margin around the resection cavity improved local control without increasing toxicity compared with our prior technique with no margin.
Tissue-specific alternative splicing is critical for the emergence of tissue identity during development, yet the role of this process in malignant transformation is undefined. Tissue-specific ...splicing involves evolutionarily conserved, alternative exons that represent only a minority of the total alternative exons identified. Many of these conserved exons have functional features that influence signaling pathways to profound biological effect. Here, we determined that lineage-specific splicing of a brain-enriched cassette exon in the membrane-binding tumor suppressor annexin A7 (ANXA7) diminishes endosomal targeting of the EGFR oncoprotein, consequently enhancing EGFR signaling during brain tumor progression. ANXA7 exon splicing was mediated by the ribonucleoprotein PTBP1, which is normally repressed during neuronal development. PTBP1 was highly expressed in glioblastomas due to loss of a brain-enriched microRNA (miR-124) and to PTBP1 amplification. The alternative ANXA7 splicing trait was present in precursor cells, suggesting that glioblastoma cells inherit the trait from a potential tumor-initiating ancestor and that these cells exploit this trait through accumulation of mutations that enhance EGFR signaling. Our data illustrate that lineage-specific splicing of a tissue-regulated alternative exon in a constituent of an oncogenic pathway eliminates tumor suppressor functions and promotes glioblastoma progression. This paradigm may offer a general model as to how tissue-specific regulatory mechanisms can reprogram normal developmental processes into oncogenic ones.
Glioblastoma (GBM) is the most common and highly lethal primary malignant brain tumor in adults. There is a dire need for easily accessible, noninvasive biomarkers that can delineate underlying ...molecular activities and predict response to therapy. To this end, we sought to identify subtypes of GBM, differentiated solely by quantitative magnetic resonance (MR) imaging features, that could be used for better management of GBM patients. Quantitative image features capturing the shape, texture, and edge sharpness of each lesion were extracted from MR images of 121 single-institution patients with de novo, solitary, unilateral GBM. Three distinct phenotypic "clusters" emerged in the development cohort using consensus clustering with 10,000 iterations on these image features. These three clusters--pre-multifocal, spherical, and rim-enhancing, names reflecting their image features--were validated in an independent cohort consisting of 144 multi-institution patients with similar tumor characteristics from The Cancer Genome Atlas (TCGA). Each cluster mapped to a unique set of molecular signaling pathways using pathway activity estimates derived from the analysis of TCGA tumor copy number and gene expression data with the PARADIGM (Pathway Recognition Algorithm Using Data Integration on Genomic Models) algorithm. Distinct pathways, such as c-Kit and FOXA, were enriched in each cluster, indicating differential molecular activities as determined by the image features. Each cluster also demonstrated differential probabilities of survival, indicating prognostic importance. Our imaging method offers a noninvasive approach to stratify GBM patients and also provides unique sets of molecular signatures to inform targeted therapy and personalized treatment of GBM.
Abstract
BACKGROUND:
An alternative treatment option to whole-brain irradiation after surgical resection of brain metastases is resection cavity stereotactic radiosurgery (SRS).
OBJECTIVE:
To review ...the dynamics of cavity volume change after surgical resection with the goal of determining the optimal timing for cavity SRS.
METHODS:
Preresection tumor, postresection/pre-SRS cavity, and post-SRS cavity volumes were measured for 68 cavities in 63 patients treated with surgery and postresection cavity SRS. Percent differences between volumes were calculated and correlation analyses were performed to assess volume changes before and after SRS.
RESULTS:
For the majority of tumors, the postresection cavity volume was smaller than the preresection tumor volume by a median percent volume change of −29% (range, −82% to 1258%), with larger preresection tumors resulting in greater cavity shrinkage (P < .001). To determine the optimal timing for cavity SRS, we examined cavity volume dynamics by comparing the early postresection (postoperative days 0–3) and treatment planning magnetic resonance imaging scans (median time to magnetic resonance imaging, 20 days; range, 9-33 days) and found no association between the postresection day number and volume change (P = .75). The volume decrease resulting from tumor resection was offset by the addition of a 2-mm clinical target volume margin, which is our current technique.
CONCLUSION:
The greatest volume change occurs immediately after surgery (postoperative days 0–3) with no statistically significant volume change occurring up to 33 days after surgery for most patients. Therefore, there is no benefit of cavity shrinkage in waiting longer than the first 1 to 2 weeks to perform cavity SRS.
NFKBIA Deletion in Glioblastomas Bredel, Claudia; Bredel, Markus; Scholtens, Denise M ...
The New England journal of medicine,
02/2011, Volume:
364, Issue:
7
Journal Article, Web Resource
Peer reviewed
This study shows that the tumor-suppressor gene NFKBIA is deleted in glioblastomas and suggests a degree of mutual exclusivity between these deletions and amplification of EGFR in these tumors. Both ...NFKBIA deletion and EGFR amplification are associated with poor survival.
Glioblastoma multiforme is the most common and most deadly primary brain tumor.
1
It is a complex disease, in which many signaling pathways are disrupted.
2
–
7
Almost all glioblastomas have excessive activation of the epidermal growth factor receptor (EGFR) pathway,
8
often brought about by amplification (see the Glossary for this and other key terms) or activating mutations of the EGFR oncogene.
9
Alternative mechanisms of the activation of the EGFR pathway may exist in tumors that do not have alterations of
EGFR
.
Nuclear factor of κ-light polypeptide gene enhancer in B-cells (NF-κB) is a transcription factor activated by the EGFR pathway. . . .
To report the outcomes of repeat stereotactic radiosurgery (SRS), deferring whole-brain radiation therapy (WBRT), for distant intracranial recurrences and identify factors associated with prolonged ...overall survival (OS).
We retrospectively identified 652 metastases in 95 patients treated with 2 or more courses of SRS for brain metastases, deferring WBRT. Cox regression analyzed factors predictive for OS.
Patients had a median of 2 metastases (range, 1-14) treated per course, with a median of 2 courses (range, 2-14) of SRS per patient. With a median follow-up after first SRS of 15 months (range, 3-98 months), the median OS from the time of the first and second course of SRS was 18 (95% confidence interval CI 15-24) and 11 months (95% CI 6-17), respectively. On multivariate analysis, histology, graded prognostic assessment score, aggregate tumor volume (but not number of metastases), and performance status correlated with OS. The 1-year cumulative incidence, with death as a competing risk, of local failure was 5% (95% CI 4-8%). Eighteen (24%) of 75 deaths were from neurologic causes. Nineteen patients (20%) eventually received WBRT. Adverse radiation events developed in 2% of SRS sites.
Multiple courses of SRS, deferring WBRT, for distant brain metastases after initial SRS, seem to be a safe and effective approach. The graded prognostic assessment score, updated at each course, and aggregate tumor volume may help select patients in whom the deferral of WBRT might be most beneficial.
Abstract
BACKGROUND
Single-session stereotactic radiosurgery (SRS) treatment of vestibular schwannomas results in excellent tumor control. It is not known whether functional outcomes can be improved ...by fractionating the treatment over multiple sessions.
OBJECTIVE
To examine tumor control and complication rates after multisession SRS.
METHODS
Three hundred eighty-three patients treated with SRS from 1999 to 2007 at Stanford University Medical Center were retrospectively reviewed. Ninety percent were treated with 18 Gy in 3 sessions, targeting a median tumor volume of 1.1 cm3 (range, 0.02-19.8 cm3).
RESULTS
During a median follow-up duration of 3.6 years (range, 1-10 years), 10 tumors required additional treatment, resulting in 3- and 5-year Kaplan-Meier tumor control rates of 99% and 96%, respectively. Five-year tumor control rate was 98% for tumors > 3.4 cm3. Neurofibromatosis type 2–associated tumors were associated with worse tumor control (P = .02). Of the 200 evaluable patients with pre-SRS serviceable hearing (Gardner-Robertson grade 1 and 2), the crude rate of serviceable hearing preservation was 76%. Smaller tumor volume was associated with hearing preservation (P = .001). There was no case of post-SRS facial weakness. Eight patients (2%) developed trigeminal dysfunction, half of which was transient.
CONCLUSION
Multisession SRS treatment of vestibular schwannomas results in an excellent rate of tumor control. The hearing, trigeminal nerve, and facial nerve function preservation rates reported here are promising.
Gangliogliomas rarely occur in the sella or suprasellar region and are almost never seen in the pituitary stalk. Seven cases of gangliogliomas occurring in this region have been reported; only one ...case involved a tumor within the pituitary stalk. Of the six tumors external to the pituitary stalk, two occurred in the neurohypophysis, one was in the adenohypophysis, the location of one was unspecified, and two extensively invaded the optic chiasm, hypothalamus and brainstem. This is only the second reported case of a pituitary stalk ganglioglioma, and it is unique in its use of an extended endoscopic endonasal approach for biopsy.
A 51-year old woman presented with an eleven-month history of polydipsia and polyuria leading to the diagnosis of diabetes insipidus. Magnetic Resonance Imaging of the brain revealed contrast-enhanced thickening and anterior bowing of the hypophyseal stalk. An extended endoscopic endonasal approach permitted midline removal of the tuberculum sella, opening of underlying dura, and exposure of the pituitary stalk. A firm, white, 4 mm diameter mass, integral to the right side of the enlarged pituitary stalk was seen and biopsied. Histopathological analysis was consistent with WHO grade 1 ganglioglioma. The patient tolerated the procedure well and required no endocrinologic treatment other than desmopressin.
Pituitary stalk gangliogliomas are extremely rare. The diagnosis should be considered in patients with pituitary stalk enlargement. Endoscopic endonasal approach is a safe surgical approach to establish a tissue diagnosis which is essential for pathologic certainty given the wide differential diagnosis of stalk lesions.
Single-modality treatment of large brain metastases (>2 cm) with whole-brain irradiation, stereotactic radiosurgery (SRS) alone, or surgery alone is not effective, with local failure (LF) rates of ...50% to 90%. Our goal was to improve local control (LC) by using multimodality therapy of surgery and adjuvant SRS targeting the resection cavity.
We retrospectively evaluated 97 patients with brain metastases >2 cm in diameter treated with surgery and cavity SRS. Local and distant brain failure (DF) rates were analyzed with competing risk analysis, with death as a competing risk. The overall survival rate was calculated by the Kaplain-Meier product-limit method.
The median imaging follow-up duration for all patients was 10 months (range, 1-80 months). The 12-month cumulative incidence rates of LF, with death as a competing risk, were 9.3% (95% confidence interval CI, 4.5%-16.1%), and the median time to LF was 6 months (range, 3-17 months). The 12-month cumulative incidence rate of DF, with death as a competing risk, was 53% (95% CI, 43%-63%). The median survival time for all patients was 15.6 months. The median survival times for recursive partitioning analysis classes 1, 2, and 3 were 33.8, 13.7, and 9.0 months, respectively (p = 0.022). On multivariate analysis, Karnofsky Performance Status (≥80 vs. <80; hazard ratio 0.54; 95% CI 0.31-0.94; p = 0.029) and maximum preoperative tumor diameter (hazard ratio 1.41; 95% CI 1.08-1.85; p = 0.013) were associated with survival. Five patients (5%) required intervention for Common Terminology Criteria for Adverse Events v4.02 grade 2 and 3 toxicity.
Surgery and adjuvant resection cavity SRS yields excellent LC of large brain metastases. Compared with other multimodality treatment options, this approach allows patients to avoid or delay whole-brain irradiation without compromising LC.
Hormonal insufficiency of 1 or more pituitary axes can appear after pituitary surgery. Adrenal axis impairment after surgery can lead to serious consequences if not identified and treated.
Assess ...early and late postoperative adrenal insufficiency (AI) and identify the risk factors predicting their occurrence after endoscopic transsphenoidal resection of pituitary adenomas.
Retrospective review identified 176 pituitary adenomas resected using an endoscopic transsphenoidal approach. Patients taking steroids preoperatively, Cushing disease patients, and patients with incomplete records were excluded. Sixty-nine patients were excluded according to our exclusion criteria.
The study group thus included 107 patients (total of 111 operations). The median age was 50 years (range, 18–89 years). The median duration of follow-up was 30 months (range, 6–74 months). Eighty-three patients (74.7%) had macroadenomas, and 89 (59.3%) had nonfunctional adenomas. Of the 111 procedures, 61 patients (55%) had early AI. Of the 61 patients, 48 patients (79%) were not taking steroids in long-term follow-up, and only 13 (21%) required long-term replacement. Sixteen of the patients undergoing 111 procedures (14.4%) had AI on long-term follow-up. Of those 16 patients, 13 were already taking steroids and 3 had new diagnoses of AI. Age, male gender, and cerebrospinal fluid (CSF) leaks were associated with persistent postoperative AI (P = 0.018, P = 0.001, P = 0.007, respectively).
Hypothalamic pituitary adrenal axis insufficiency is common after endoscopic transsphenoidal surgery. Male gender, age greater than 50 years, visual impairment, and intraoperative CSF leak were correlated with late postoperative AI. More than two thirds of patients in whom early AI developed did not require steroids in the long term.
•Of 111 endoscopic transsphenoidal surgery for pituitary adenoma, 61 patients (55%) had early adrenal insufficiency (AI). Of the 61 patients, 48 patients (79%) were not using steroids at long-term follow-up and only 13 (21%) required long-term replacement.•16/111 patients (14.4%) had AI at long-term follow-up. Of those 16 patients, 13 were already using steroids and 3 had new diagnoses of AI.•Male gender, age older than 50 years, visual impairment, and intraoperative cerebrospinal fluid leak were correlated with late postoperative AI.•More than two thirds of patients in whom early AI developed did not require steroids in the long term.
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