Postoperative Stereotactic Radiotherapy Research Articles

MSOR6 Presentation Time: 5:25 PM: Intraoperative or Postoperative Stereotactic Radiotherapy for Brain Metastases: Time to Systemic Treatment Onset and Other Patient-Relevant Outcomes

MSOR6 Presentation Time: 5:25 PM: Intraoperative or Postoperative Stereotactic Radiotherapy for Brain Metastases: Time to Systemic Treatment Onset and Other Patient-Relevant Outcomes

Determining Patterns of Relapse Following Pelvic Exenteration for Centrally Recurrent Gynecological Cancer: The Feasibility of Postoperative Stereotactic Radiotherapy

Determining Patterns of Relapse Following Pelvic Exenteration for Centrally Recurrent Gynecological Cancer: The Feasibility of Postoperative Stereotactic Radiotherapy

Radiomics-based prediction of local control in patients with brain metastases following postoperative stereotactic radiotherapy.

Surgical resection is the standard of care for patients with large or symptomatic brain metastases (BMs). Despite improved local control after adjuvant stereotactic radiotherapy, the risk of local failure (LF) persists. Therefore, we aimed to develop and externally validate a pre-therapeutic radiomics-based prediction tool to identify patients at high LF risk. Data were collected from A Multicenter Analysis of Stereotactic Radiotherapy to the Resection Cavity of BMs (AURORA) retrospective study (training cohort: 253 patients from 2 centers; external test cohort: 99 patients from 5 centers). Radiomic features were extracted from the contrast-enhancing BM (T1-CE MRI sequence) and the surrounding edema (T2-FLAIR sequence). Different combinations of radiomic and clinical features were compared. The final models were trained on the entire training cohort with the best parameter set previously determined by internal 5-fold cross-validation and tested on the external test set. The best performance in the external test was achieved by an elastic net regression model trained with a combination of radiomic and clinical features with a concordance index (CI) of 0.77, outperforming any clinical model (best CI: 0.70). The model effectively stratified patients by LF risk in a Kaplan-Meier analysis (P < .001) and demonstrated an incremental net clinical benefit. At 24 months, we found LF in 9% and 74% of the low and high-risk groups, respectively. A combination of clinical and radiomic features predicted freedom from LF better than any clinical feature set alone. Patients at high risk for LF may benefit from stricter follow-up routines or intensified therapy.

1137P Treatment strategies and survival outcomes in a nationwide, population-based cohort of patients with melanoma brain metastases: The role of planned shift in systemic therapy and postoperative stereotactic radiotherapy

1137P Treatment strategies and survival outcomes in a nationwide, population-based cohort of patients with melanoma brain metastases: The role of planned shift in systemic therapy and postoperative stereotactic radiotherapy

Post-Operative Stereotactic Radiotherapy for Resected Brain Metastases: Results of the Multicenter Analysis (AURORA) of the German Working Group "Stereotactic Radiotherapy"

While the results of prospective studies support the use of postoperative stereotactic radiotherapy (RT) to the resection cavity (RC) as the standard of care after surgery, there are several issues that need to be investigated such as factors for improving local control, risk of leptomeningeal disease and radiation necrosis. Further, the optimal dose and fractionation is still under debate. The working group "Stereotactic Radiotherapy" of the German Society of Radiation Oncology (DEGRO) analyzed its multi-institutional database with 661 patients who received postoperative stereotactic RT to the RC. Treatment was performed at 13 centers between 2008 and 2021. Patient characteristics, treatment details, and follow-up data including overall survival (OS), local control (LC) were evaluated. Cox Regression and Kaplan-Meier curves with Log-rank Tests were calculated for selected variables. In this retrospective study, overall survival was 61.5% at 1 year, 47.6% at 2 years, and 35.5% at 3 years, and local control was 84.6% at 1 year, 74.8% at 2 years, and 72.8% at 3 years. 96% of patients were treated with hypofractionated stereotactic radiotherapy (HSRT), only 26 patients received single fraction radiosurgery (4%). Prognostic factors associated with overall survival were Karnofsky Performance Status, RPA and GPA class, controlled primary tumor and absence of extracranial metastases, whereas prognostic factor associated with local control was planning target volume (23 mL or less). HSRT is the most common fractionation form in the treatment of RCs in this multicenter analysis. This approach results in excellent OS and LC outcomes. OS in patients with resected brain metastases is mainly influenced by performance status. In regard to local control, RT of large cavities remain a challenge with significantly worse outcome.

Intraoperative or postoperative stereotactic radiotherapy for brain metastases: time to systemic treatment onset and other patient-relevant outcomes

PurposeIntraoperative radiotherapy (IORT) has become a viable treatment option for resectable brain metastases (BMs). As data on local control and radiation necrosis rates are maturing, we focus on meaningful secondary endpoints such as time to next treatment (TTNT), duration of postoperative corticosteroid treatment, and in-hospital time.MethodsPatients prospectively recruited within an IORT study registry between November 2020 and June 2023 were compared with consecutive patients receiving adjuvant stereotactic radiotherapy (SRT) of the resection cavity within the same time frame. TTNT was defined as the number of days between BM resection and start of the next extracranial oncological therapy (systemic treatment, surgery, or radiotherapy) for each of the groups.ResultsOf 95 BM patients screened, IORT was feasible in 84 cases (88%) and ultimately performed in 64 (67%). The control collective consisted of 53 SRT patients. There were no relevant differences in clinical baseline features. Mean TTNT (range) was 36 (9 − 94) days for IORT patients versus 52 (11 − 126) days for SRT patients (p = 0.01). Mean duration of postoperative corticosteroid treatment was similar (8 days; p = 0.83), as was mean postoperative in-hospital time (11 versus 12 days; p = 0.97). Mean total in-hospital time for BM treatment (in- and out-patient days) was 11 days for IORT versus 19 days for SRT patients (p < 0.001).ConclusionIORT for BMs results in faster completion of interdisciplinary treatment when compared to adjuvant SRT, without increasing corticosteroid intake or prolonging in-hospital times. A randomised phase III trial will determine the clinical effects of shorter TTNT.

Hypofractionated stereotactic radiotherapy (HFSRT) versus single fraction stereotactic radiosurgery (SRS) to the resection cavity of brain metastases after surgical resection (SATURNUS): study protocol for a randomized phase III trial

BackgroundThe brain is a common site for cancer metastases. In case of large and/or symptomatic brain metastases, neurosurgical resection is performed. Adjuvant radiotherapy is a standard procedure to minimize the risk of local recurrence and is increasingly performed as local stereotactic radiotherapy to the resection cavity. Both hypofractionated stereotactic radiotherapy (HFSRT) and single fraction stereotactic radiosurgery (SRS) can be applied in this case. Although adjuvant stereotactic radiotherapy to the resection cavity is widely used in clinical routine and recommended in international guidelines, the optimal fractionation scheme still remains unclear. The SATURNUS trial prospectively compares adjuvant HFSRT with SRS and seeks to detect the superiority of HFSRT over SRS in terms of local tumor control.MethodsIn this single center two-armed randomized phase III trial, adjuvant radiotherapy to the resection cavity of brain metastases with HFSRT (6 – 7 × 5 Gy prescribed to the surrounding isodose) is compared to SRS (1 × 12–20 Gy prescribed to the surrounding isodose). Patients are randomized 1:1 into the two different treatment arms. The primary endpoint of the trial is local control at the resected site at 12 months. The trial is based on the hypothesis that HFSRT is superior to SRS in terms of local tumor control.DiscussionAlthough adjuvant stereotactic radiotherapy after resection of brain metastases is considered standard of care treatment, there is a need for further prospective research to determine the optimal fractionation scheme. To the best of our knowledge, the SATURNUS study is the only randomized phase III study comparing different regimes of postoperative stereotactic radiotherapy to the resection cavity adequately powered to detect the superiority of HFSRT regarding local control.Trial registrationThe study was retrospectively registered with ClinicalTrials.gov, number NCT05160818, on December 16, 2021. The trial registry record is available on https://clinicaltrials.gov/study/NCT05160818. The presented protocol refers to version V1.3 from March 21, 2021.

Separation Operation Followed by Stereotactic Radiotherapy in the Treatment of Spinal Metastasis From Hepatocellular Carcinoma: A Retrospective Cohort Study.

Retrospective cohort study. Spinal metastasis from hepatocellular carcinoma is rapidly progressive and predisposes to spinal disability, cord compression and further neural injury, leading to poor prognosis. Currently, it is still challenging to look for a treatment strategy that can improve the quality of life of patients and even directly prolong the survival time. This study attempts to evaluate the clinical efficacy of separation operation combined with postoperative stereotactic radiotherapy (SRT/SRS) in the treatment of hepatocellular carcinoma patients developing spinal metastasis and epidural spinal cord compression. Patients with metastases spinal cord compression from hepatocellular carcinoma were studied retrospectively and divided into two groups, the SO group (who undergo separation operations combined with postoperative SRS, n = 32) and RT group (who received only SRS, n = 28). The visual Analogue Scale (VAS) pain score, Frankel grade, Karnofsky performance score, and Quality of Life (SF-36) score were comparatively analyzed between the two groups. Significantly higher VAS pain scores, Frankel grades, Karnofsky performance scores and Quality of Life (SF-36) scores were demonstrated in patients with combination treatment than in patients with SRS alone. Separation operations are effective surgical procedure for the treatment of spinal metastatic tumor from hepatocellular carcinoma with spinal cord compression. The combination with postoperative SRS can significantly improve the quality of life in this patient population via spinal canal decompression and spinal stability reconstruction.

Minimizing Intracranial Disease Before Stereotactic Radiation in Single or Solitary Brain Metastases.

Stereotactic radiotherapy (SRT) in multiple fractions (typically ≤5) can effectively treat a wide range of brain metastases, including those less suitable for single-fraction stereotactic radiosurgery (SRS). Prior prospective studies on surgical resection with stereotactic radiation have focused exclusively on SRS, and retrospective studies have shown equivocal results regarding whether surgery is associated with improved outcomes compared with SRT alone. We compared resection with postoperative cavity SRT or SRS to SRT alone in patients with 1 brain metastasis, while including patients receiving SRS alone as an additional reference group. We studied 716 patients in a retrospective, single-institution cohort diagnosed with single or solitary brain metastases from 2007 to 2020. Patients receiving whole-brain radiotherapy were excluded. Cox proportional hazards models were constructed for overall survival and additional intracranial outcomes. After adjustment for potential confounders, surgery with cavity SRT/SRS was associated with decreased all-cause mortality (hazard ratio [HR]: 0.39, 95% CI [0.27-0.57], P = 1.52 × 10 -6 ) compared with SRT alone, along with lower risk of neurological death attributable to intracranial tumor progression (HR: 0.46, 95% CI [0.22-0.94], P = 3.32 × 10 -2 ) and radiation necrosis (HR: 0.15, 95% CI [0.06-0.36], P = 3.28 × 10 -5 ). Surgery with cavity SRS was also associated with decreased all-cause mortality (HR: 0.52, 95% CI [0.35-0.78], P = 1.46 × 10 -3 ), neurological death (HR: 0.30, 95% CI [0.10-0.88], P = 2.88 × 10 -2 ), and radiation necrosis (HR: 0.14, 95% CI [0.03-0.74], P = 2.07 × 10 -2 ) compared with SRS alone. Surgery was associated with lower risk of all-cause mortality and neurological death in cardinality-matched subsets of the cohort. Among surgical patients, gross total resection was associated with extended overall survival (HR: 0.62, 95% CI [0.40-0.98], P = 4.02 × 10 -2 ) along with lower risk of neurological death (HR: 0.31, 95% CI [0.17-0.57], P = 1.84 × 10 -4 ) and local failure (HR: 0.34, 95% CI [0.16-0.75], P = 7.08 × 10 -3 ). In patients with 1 brain metastasis, minimizing intracranial disease specifically before stereotactic radiation is associated with improved oncologic outcomes.

Personalized treatment of brain metastases: Evolving survival prediction models may benefit from evaluation of serum tumor markers (narrative review).

Treatment of a limited number of brain metastases (oligometastases) might include complex and sometimes invasive approaches, e.g. neurosurgical resection followed by post-operative stereotactic radiotherapy, and thus, correct identification of patients who are appropriate candidates is crucial. Both, staging procedures that visualize the true number of metastastic lesions and prognostic assessments that identify patients with limited survival, who should be managed with less complex, palliative approaches, are necessary before proceeding with local treatment that aims at eradication of all oligometastases. Some of the prognostic models, e.g. the LabBM score (laboratory parameters in patients with brain metastases), include blood biomarkers believed to represent surrogate markers of disease extent. In a recent study, patients with oligometastases and a LabBM score of 0 (no abnormal biomarkers) had an actuarial 5-year survival rate of 27% after neurosurgical resection and 39% after stereotactic radiotherapy. Other studies have tied serum tumor markers such as carcinoembryonic antigen (CEA) to survival outcomes. Even if head-to-head comparisons and large-scale definitive analyses are lacking, the available data suggest that attempts to integrate tumor marker levels in blood biomarker-based survival prediction models are warranted.

Hypofractionated postoperative stereotactic radiotherapy for large resected brain metastases

PurposeThe aim of the present retrospective study was to report outcomes after hypofractionated stereotactic radiotherapy (HSRT) for resected brain metastases (BM). Patients and methodsWe reviewed results of patients with resected BM treated with postoperative HSRT (3×7.7Gy to the prescription isodose 70%) between May 2013 and June 2020. Local control (LC), distant brain control (DBC), overall survival (OS), leptomeningeal disease relapse (LMDR), and radiation necrosis (RN) occurrence were reported. ResultsTwenty-two patients with 23 brain cavities were included. Karnofsky Performance status (KPS) was≥70 in 77.3%. Median preoperative diameter was 37mm [21.0–75.0] and median planning target volume (PTV) was 23 cm3 [9.9–61.6]. Median time from surgery to SRT was 69 days [7–101] and 48% of patients had a local relapse on pre-SRT imaging. Median follow-up was 17.5 months [1.6–95.9]. One and two-year LC rates were 60.9 and 52.2% respectively. One and 2-year DBC rates were 45.5 and 40.9%. Median OS was 16.5 months. Four patients (18.2%) presented LMDR during follow-up. RN occurred in 6 patients (27.2%). Three factors were associated with OS: ECOG-PS (P=0.009), KPS (P=0.04), cystic or solid nature of the metastasis before surgery (P=0.037). Several factors were related to RN occurrence: PTV diameter and volume, Normal brain V21, V21 and V24 isodoses volumes. ConclusionHSRT is the most widely used scheme for larger brain cavities after surgery. The optimal dose and scheme remain to be defined as well as the optimal delay between postoperative SRT and surgery. Dose escalation may be necessary, especially in case of subtotal resection.

Management of Medial Sphenoid Wing Meningioma Involving the Cavernous Sinus: A Single-Center Series of 105 Cases.

Simple SummaryMedial sphenoid wing meningiomas are among the three most common intracranial meningiomas. They present a challenge to neurosurgeons, especially when they invade critical neurovascular structures and the cavernous sinus. This study was designed to evaluate prognostic features influencing recurrence and progression-free survival of medial sphenoid meningiomas invading the cavernous sinus, with a particular focus on the impact of surgery and postoperative radiotherapy. A retrospective analysis was conducted of the database of our institution. Included were 105 cases of medial sphenoid wing meningiomas with invasion of the cavernous sinus, of which 64 were treated by surgery alone and 41 were treated by surgery plus radiotherapy. Near-total resection did reduce the risk of tumor recurrence significantly compared to subtotal resection. Progression-free survival was also significantly prolonged after postoperative radiotherapy. In conclusion, we found that performing a maximal safe resection is the factor most strongly associated with a lower recurrence rate in patients with medial sphenoid meningioma infiltrating the cavernous sinus, and that postoperative stereotactic radiotherapy of the residual tumor also significantly prolongs PFS.Objective: Medial sphenoid wing meningiomas are among the three most common intracranial meningiomas. These tumors pose a challenge to neurosurgeons in terms of surgical treatment, as they may involve critical neurovascular structures and invade the cavernous sinus. In case of the latter, a complete resection may not be achievable. The purpose of this study was to investigate prognostic features affecting recurrence and progression-free survival (PFS) of medial sphenoid wing meningiomas involving the cavernous sinus, focusing on the contribution of surgery and postoperative radiotherapy. Methods: A retrospective analysis was conducted of the database of our institution, and 105 cases of medial sphenoid wing meningioma with invasion of the cavernous sinus, which were treated between 1998 and 2019, were included. Surgical treatment only was performed in 64 cases, and surgical treatment plus postoperative radiotherapy was performed in 41 cases. Kaplan–Meier analysis was conducted to estimate median survival and PFS rates, and Cox regression analysis was applied to determine significant factors that were associated with each therapeutic modality. Results: The risk of recurrence was significantly reduced after near-total resection (NTR) (p-value = 0.0011) compared to subtotal resection. Progression-free survival was also significantly prolonged after postoperative radiotherapy (p-value = 0.0002). Conclusions: Maximal safe resection and postoperative stereotactic radiotherapy significantly reduced the recurrence rate of medial sphenoid wing meningiomas with infiltration of the cavernous sinus.

Preoperative stereotactic radiosurgery for brain metastases: the STEP study protocol for a multicentre, prospective, phase-II trial

BackgroundSurgery is an important therapeutic option for brain metastases. Currently, postoperative stereotactic radiosurgery (SRT) leads to 6-month and 1-year local control estimated at 70 and 62% respectively. However, there is an increased risk of radio-necrosis and leptomeningeal relapse. Preoperative SRT might be an alternative, providing local control remains at least equivalent. It is an innovative concept that could enable the stereotactic benefits to be retained with advantages over post-operative SRT.MethodsSTEP has been designed as a national, multicentre, open-label, prospective, non-randomized, phase-II trial. Seventeen patients are expected to be recruited in the study from 7 sites and they will be followed for 12 months. Patients with more than 4 distinct brain metastases, including one with a surgical indication, and an indication for SRT and surgery, are eligible for enrolment. The primary objective of the trial is to assess 6-month local control after preoperative SRT. The secondary objectives include the assessment of local control, radio-necrosis, overall survival, toxicities, leptomeningeal relapse, distant control, cognitive function, and quality of life. The experimental design is based on a Flemming plan.DiscussionThere is very little data available in the literature on preoperative SRT: there have only been 3 American single or two-centre retrospective studies. STEP is the first prospective trial on preoperative SRT in Europe. Compared to postoperative stereotactic radiotherapy, preoperative stereotactic radiotherapy will enable reduction in the irradiated volume, leptomeningeal relapse and the total duration of the combined treatment (from 4 to 6 weeks to a few days).Trial registration numberClinicaltrials.gov: NCT04503772, registered on August 07, 2020. Identifier with the French National Agency for the Safety of Medicines and Health Products (ANSM): N°ID RCB 2020-A00403–36, registered in February 2020. Protocol: version 4, 07 December 2020.

Application of a multi-institutional nomogram predicting salvage whole brain radiation-free survival to patients treated with postoperative stereotactic radiotherapy for brain metastases

PurposeThe ultimate goal of stereotactic radiotherapy (SRT) of brain metastases (BM) is to avoid or postpone whole brain radiotherapy (WBRT). A nomogram based on multi-institutional data was developed by Gorovets, et al. to estimate the 6 and 12-months WBRT-free survival (WFS). The aim of the current retrospective study was to validate the nomogram in a cohort of postoperative BM patients treated with adjuvant SRT. Material and methodsWe reviewed the data of 68 patients treated between 2008–2017 with postoperative SRT for BM. The primary endpoint was the WFS. The receiver operating characteristic curve and area under the curve (AUC) were calculated for both 6- and 12-months time points. ResultsAfter a median follow-up of 64 months, the 1-year cumulative incidence of local and distant brain relapse rates were 15% [95% CI=8–26%] and 34% [95% CI=24–48%], respectively. At recurrence, repeated SRT or salvage WBRT were applied in 33% and 57% cases, respectively. The WFS rates at 6 and 12 months were 88% [95% CI=81–97%] and 67% [95% CI=56–81%], respectively. Using the Gorovets nomogram, the 6 months rates were overestimated while they were accurate at 12 months. AUC values were 0.47 and 0.62 for the 6- and 12-months respectively. Overall, Harrell's concordance index was 0.54. ConclusionThis nomogram-predicted well the 12 months WFS but its discriminative power was quite low. This underlines the limits of this kind of predictive tool and leads us to consider the use of big data analysis in the future.

First Russian experience of the stereotactic radiotherapy on the prostate bed

Purpose. Assess the safety of postoperative radiation therapy on the area of the prostate bed (PB) using extreme dose hypofractionation (5 fractions of 6.67 Gr).&#x0D; Materials and methods. from April 2019 to March 2020 at the National Medical Center of Oncology named after N.N. Petrov of the Ministry of Health of the Russian Federation in the first 15 patients of the prostate cancer carried out stereotactic radiation therapy (SRT) on the PB. Depending on the clinical situation, adjuvant and salvage SRT were distinguished. Linear electron accelerators with 6 MeV energy are used for treatment. Three factional regimes were evaluated: 5 factions of 6.6 Gr, 5 factions of 6.8 Gr and 5 factions of 7 Gr. The clinical target volume is defined by RTOG (2010).&#x0D; Results. The median of follow-up was 7.6 (1.3-11.6) months. Of the 15 patients, adjuvant SRT performed three observed, and the remaining 12 patients salvage SRT (4 early, 8 delayed). Acute radiation toxicity was estimated in 12 patients. Early impairment from the lower urinary tract 1 degree was observed in 8 (66.7%) 12 of them. Toxicity of 2 or more degree in the early period was not observed. Clinical signs of early 1st degree toxicity from the rectum were found in five (41.7%) of the bowel of the 12 observed. One patient (8.3%) there was a mixture of blood in the feces, which required a medical correction, which was considered as toxicity of the 2nd degree.&#x0D; Conclusions. Postoperative SRT of the PB region is a promising modern method of radiation treatment of patients with prostate cancer. The presented methods of adjuvant and salvage SRT are feasible in clinical practice and are characterized by an acceptable level of early radiation toxicity.

P03.02 Risk of leptomeningeal dissemination in patients treated with postoperative stereotactic radiotherapy of brain metastases

Abstract Background There is a body of evidence that the risk of leptomeningeal dissemination (LMD) is increased in the postoperative stereotactic radiotherapy (SRT) of brain metastases (BM) compared to adjuvant whole brain radiotherapy (WBRT). The proposed mechanism is an iatrogenic tumor dissemination into the cerebrospinal fluid at time of surgery. Including a wider volume of meningeal wall and the entire surgical track in the definition of the postoperative SRT clinical target volume (CTV) to decrease LMD is still controversial. The aim of this study was to retrospectively analyze the outcome of adjuvant SRT targeted at resection cavities of BM without previous WBRT. MATERIAL / METHODS We reviewed 70 patients treated with postoperative SRT for BM. Stereotactic planning computed tomography and planning MRI were imported into iPlan RT image software for image registration and TV delineation. The CTV consisted of any residual enhancement and all resected cavity including a safety margin of 1 to 2 mm. Only in cases of superficial initial tumor with meningeal contact was the CTV enlarged to the adjacent meningeal wall, but never included edema or the entire surgical track. Patients underwent regular follow-up MRI. The cumulative incidence rates of LMD was retrospectively calculated as well as patterns of failure. RESULTS The most common histological type was non small cell lung cancer in 61.4%. There were 38.6% infratentorial locations and 37.2 % superficial lesions. En bloc resection was achieved in 60% and compete resection in 75.7%. After a median imaging follow up time of 16.7 months, 54.3% of patients experienced distant brain failure. LMD occurred in 9 of 70 patients (12.9 %) at a median time of 10.7 months. Survival without LMD was 88% at 1 year (IC 95% 79%-97%) and 82% at 2years (IC 95% 72%-94%). In three quarter of cases, LMD interested superficial lesions. In univariate analysis, survival rates without LMD at 1 year for superficial and deep lesions were 88 % and 94 %, respectively (p=0.49). We report only one recurrence in the surgical track (1.42%). CONCLUSION The risk of LMD was comparable to the literature (11–17%). Superficial lesions were slightly more likely to relapse in the meninges, but it was non-significant. The risk of recurrence in the surgical track is negligible. Our results do not support the current guidelines recommending the systematic inclusion of the surgical track and the related meninges in the CTV.

Strategy and Technique of Endonasal Endoscopic Bony Decompression and Selective Tumor Removal in Symptomatic Skull Base Meningiomas of the Cavernous Sinus and Meckel's Cave

Parasellar meningiomas involving the cavernous sinus and Meckel's cave pose a management challenge because of invasion around neurovascular structures and the pituitary gland. The management options range from aggressive resection to focused radiotherapy alone. We present a strategy for these tumors that includes endonasal bony decompression, partial tumor removal, and stereotactic radiotherapy (SRT) in select cases. The tumor location, previous treatments, cranial neuropathies, pituitary dysfunction, tumor control rates, use of stereotactic radiosurgery, SRT, and complications were retrospectively evaluated. Twenty patients (age range, 43-81 years; 65% women; 90% with World Health Organization grade I; median follow-up, 57 months; 14 without previous debulking and RT; 6 with previous debulking and RT) underwent endonasal bony decompression and partial tumor removal. The most common tumor locations were cavernous sinus (95%), Meckel's cave (95%), sella (75%), petroclival (60%), and optic canal/orbit (30%). Three patients with large meningiomas underwent staged transcranial and endonasal debulking. Of the 14 patients without previous debulking and RT, 11 had undergone postoperative SRT, with tumor shrinkage in 3 (27%). At the last follow-up examination, for these 14 patients and the 6 patients who had undergone previous surgery and RT, tumor control was 100% and 33%(P < 0.001) and the cranial neuropathies had improved in 57% and 33%, respectively. Major complications occurred in 2 patients: a permanent sixth cranial nerve palsy and cerebrospinal fluid leakage requiring reoperation. Endonasal bony decompression and selective tumor removal, followed by SRT, appears to be a reasonable treatment option for most previously untreated parasellar meningiomas. For patients who have undergone previous debulking and RT, new targeted treatment strategies are needed.

Preliminary Exploration of the Diagnosis and Treatment of Skull-Based Chondromyxoid Fibromas.

Chondromyxoid fibromas (CMFs) are benign tumors that occur rarely in the skull base. To conduct a preliminary exploration of the diagnosis and treatment of cranial CMFs. A retrospective analysis of 19 cases of CMFs in the base of the skull between 2009 and 2014 in our hospital was conducted. The clinical manifestations, imaging characteristics, pathology, treatment strategies, and outcomes were examined. The study cohort included 7 women (36.8%) and 12 men (63.2%), and symptom duration ranged from 1 mo to 5 yr. Of the 19 intracranial CMF cases examined, 15 (78.9%) conformed with the diagnostic criteria for extracranial CMF. Resection operations yielded subtotal removal of 13 tumors (68.4%) and partial removal of 6 tumors (31.6%). Postoperative pathological analysis demonstrated that the tumors were characterized by spindle-shaped or stellate cells arranged in a myxoid matrix without mitoses or permeation. Follow-up (range 2-7.3 yr; mean, 4.4 ± 1.7 yr) revealed that symptoms improved postoperatively in 15 cases (78.9%), were maintained in 2 cases (10.5%), and worsened in 2 cases (10.5%). Imaging follow-up revealed that residual tumors were stable in 18 cases (94.7%) and enlarged in 1 case (5.3%). An accurate diagnosis should involve comprehensive consideration of clinical, radiological, and pathological features. The treatment strategy for CMFs consists of maximizing tumor removal while protecting adjacent key structures. Postoperative stereotactic radiotherapy is appropriate for residual tumors.

A dosimetric comparison of linac-based stereotactic fractionated radiotherapy techniques for pituitary adenoma and craniopharyngioma

AbstractAimTo compare the dosimetric outcomes of linear accelerator-based stereotactic radiotherapy (SRT) techniques—static conformal field (SCF), static conformal arc (SCA) and dynamic conformal arc (DCA), for treating pituitary adenoma and craniopharyngioma.Materials and methodsComputer image sets of 20 patients with pituitary adenoma or craniopharyngioma and treated with post-operative SRT were selected for this study. For each dataset, three SRT plans, with SCF, SCA and DCA techniques were generated using Brain LAB, iPlan RT V.4.5.3, TPS software. The conformity index (CI), homogeneity index (HI), quality of coverage of the target, dose–volume histograms for the target and organs at risk (OARs) and the time taken to deliver treatment was compared across three sets of plan.ResultsThere were 12 patients with pituitary adenoma and eight with craniopharyngioma. The CI and HI were comparable across three techniques. The quality of coverage was superior in DCA technique. OARs were better spared in SCF and DCA techniques. Time taken to deliver treatment was least in SCF technique.ConclusionsThe linac-based SRT techniques SCF, SCA and DCA are efficient in delivering highly conformal and homogenous dose to the target in pituitary adenoma and craniopharyngioma. Among these three techniques, SCF and DCA had acceptable quality of coverage. The dose received by OARs was least in the SCF technique.

Increasing time to postoperative stereotactic radiation therapy for patients with resected brain metastases: investigating clinical outcomes and identifying predictors associated with time to initiation.

We sought todetermine the impact of time to initiation (TTI) of post-operative radiosurgery on clinical outcomes for patients with resected brain metastases and to identify predictors associated with TTI. All patients with resected brain metastases treated with postoperative SRS or fractionated stereotactic radiation therapy (fSRT) from 2012 to 2016at a single institution were reviewed. TTI was defined as the interval from resection to first day of radiosurgery. Receiver operating characteristic (ROC) curves were used to identify an optimal threshold for TTI with respect to local failure (LF). Survival outcomes were estimated using the Kaplan-Meier method and analyzed using the log-rank test and Cox proportional hazards models. Logistic regression models were used to identify factors associated with ROC-determined TTI covariates. A total of 79 resected lesions from 73 patients were evaluated. An ROC curve of LF and TTI identified an optimal threshold for TTI of 30.5 days, with an area under the curve of 0.637. TTI > 30days was associated with an increased hazard of LF (HR 4.525, CI 1.239-16.527) but was not significantly associated with survival (HR 1.002, CI 0.547-1.823) or distant brain failure (DBF, HR 1.943, CI 0.989-3.816). Fifteen patients (20.5%) required post-operative inpatient rehabilitation. Post-operative rehabilitation was associated with TTI > 30 days (OR 1.48, CI 1.142-1.922). In our study of resected brain metastases, longer time to initiation of post-operative radiosurgery was associated with increased local failure. Ideally, post-op SRS should be initiated within 30 days of resection if feasible.