Preoperative stereotactic radiosurgery as neoadjuvant therapy for resectable brain tumors.

PURPOSE: Stereotactic radiosurgery (SRS) is a method of delivering conformal radiation, which allows minimal radiation damage to surrounding healthy tissues. Adjuvant radiation therapy has been shown to improve local control in a variety of intracranial neoplasms, such as brain metastases, gliomas, and benign tumors (i.e., meningioma, vestibular schwannoma, etc.). For brain metastases, adjuvant SRS specifically has demonstrated positive oncologic outcomes as well as preserving cognitive function when compared to conventional whole brain radiation therapy. However, as compared with neoadjuvant SRS, larger post-operative volumes and greater target volume uncertainty may come with an increased risk of local failure and treatment-related complications, such as radiation necrosis. In addition to its role in brain metastases, neoadjuvant SRS for high grade gliomas may enable dose escalation and increase immunogenic effects and serve a purpose in benign tumors for which one cannot achieve a gross total resection (GTR). Finally, although neoadjuvant SRS has historically been delivered with photon therapy, there are high LET radiation modalities such as carbon-ion therapy which may allow radiation damage to tissue and should be further studied if done in the neoadjuvant setting. In this review we discuss the evolving role of neoadjuvant radiosurgery in the treatment for brain metastases, gliomas, and benign etiologies. We also offer perspective on the evolving role of high LET radiation such as carbon-ion therapy. METHODS: PubMed was systemically reviewed using the search terms "neoadjuvant radiosurgery", "brain metastasis", and "glioma". ' Clinicaltrials.gov ' was also reviewed to include ongoing phase III trials. RESULTS: This comprehensive review describes the evolving role for neoadjuvant SRS in the treatment for brain metastases, gliomas, and benign etiologies. We also discuss the potential role for high LET radiation in this setting such as carbon-ion radiotherapy. CONCLUSION: Early clinical data is very promising for neoadjuvant SRS in the setting of brain metastases. There are three ongoing phase III trials that will be more definitive in evaluating the potential benefits. While there is less data available for neoadjuvant SRS for gliomas, there remains a potential role, particularly to enable dose escalation and increase immunogenic effects.

Carbon Ion Radiotherapy: An Evidence-Based Review and Summary Recommendations of Clinical Outcomes for Skull-Base Chordomas and Chondrosarcomas.

Skull-base chordoma and chondrosarcoma are rare radioresistant tumors treated with surgical resection and/or radiotherapy. Because of the established dosimetric and biological benefits of heavy particle therapy, we performed a systematic and evidence-based review of the clinical outcomes of patients with skull-base chordoma and chondrosarcoma treated with carbon ion radiotherapy (CIRT). A literature review was performed using a MEDLINE search of all articles to date. We identified 227 studies as appropriate for review, and 24 were ultimately included. The published data illustrate that CIRT provides benchmark disease control outcomes for skull-base chordoma and chondrosarcoma, respectively, with acceptable toxicity. CIRT is an advanced treatment technique that may provide not only dosimetric benefits over conventional photon therapy but also biologic intensification to overcome mechanisms of radioresistance. Ongoing research is needed to define the magnitude of benefit, patient selection, and cost-effectiveness of CIRT compared to other forms of radiotherapy.

Let's make size not matter: tumor control and toxicity outcomes of hypofractionated Gamma Knife radiosurgery for large brain metastases.

PURPOSE: Management of patients with large brain metastases poses a clinical challenge, with poor local control and high risk of adverse radiation events when treated with single-fraction stereotactic radiosurgery (SF-SRS). Hypofractionated SRS (HF-SRS) may be considered, but clinical data remains limited, particularly with Gamma Knife (GK) radiosurgery. We report our experience with GK to deliver mask-based HF-SRS to brain metastases greater than 10 cc in volume and present our control and toxicity outcomes. METHODS: Patients who received hypofractionated GK radiosurgery (HF-GKRS) for the treatment of brain metastases greater than 10 cc between January 2017 and June 2022 were retrospectively identified. Local failure (LF) and adverse radiation events of CTCAE grade 2 or higher (ARE) were identified. Clinical, treatment, and radiological information was collected to identify parameters associated with clinical outcomes. RESULTS: Ninety lesions (in 78 patients) greater than 10 cc were identified. The median gross tumor volume was 16.0 cc (range 10.1-56.0 cc). Prior surgical resection was performed on 49 lesions (54.4%). Six- and 12-month LF rates were 7.3% and 17.6%; comparable ARE rates were 1.9% and 6.5%. In multivariate analysis, tumor volume larger than 33.5 cc (p = 0.029) and radioresistant histology (p = 0.047) were associated with increased risk of LF (p = 0.018). Target volume was not associated with increased risk of ARE (p = 0.511). CONCLUSIONS: We present our institutional experience treating large brain metastases using mask-based HF-GKRS, representing one of the largest studies implementing this platform and technique. Our LF and ARE compare favorably with the literature, suggesting that target volumes less than 33.5 cc demonstrate excellent control rates with low ARE. Further investigation is needed to optimize treatment technique for larger tumors.

Efficacy of ketamine mouthwash in the management of oral and pharyngeal toxicity associated with head and neck chemoradiotherapy: protocol for a phase II, Simon's two-stage trial.

INTRODUCTION: Curative intent treatment of head and neck cancer (HNC) is frequently radiation therapy over 7 weeks with concurrent chemotherapy. This regimen is effective but carries a burden of toxicity leading to severe pain and treatment breaks portending inferior outcomes. Conventional palliation methods include opioids, anticonvulsants and local anaesthetics. Breakthrough toxicities are nevertheless ubiquitous and present an urgent unmet need. Ketamine is an inexpensive drug with mechanisms of analgesia outside the opioid pathway including N-methyl-D-aspartate (NMDA) receptor antagonism and a pharmacologically unique property of opioid desensitisation. Systemic ketamine is validated in randomised controlled trials for efficacy in reducing pain and/or opioid burden in the oncologic setting. Literature supports peripherally administered ketamine for pain control without systemic toxicity. These data support our rationale of using ketamine mouthwash to decrease acute toxicity of curative treatment of HNC, the efficacy of which is our aim to elucidate. METHODS AND ANALYSIS: This is a phase II, Simon's two-stage trial. Patients have pathologically confirmed HNC and an intended regimen of 70 Gy of radiation with concurrent cisplatin. The protocol is initiated on diagnosis of grade 3 mucositis and consists of 2 weeks of 4 times daily (QID) ketamine mouthwash use. The primary endpoint is pain response defined as a combination of pain score and opioid use. 23 subjects will be enrolled in stage 1. If statistical criteria are met, 33 subjects will be enrolled in stage 2. Secondary endpoints include daily pain, daily opioid use, dysphagia at baseline and completion, nightly sleep quality, feeding tube placement and any unscheduled treatment breaks. ETHICS AND DISSEMINATION: All trial data will be stored in an Institutional Review Board (IRB) approved database. The protocol is registered under Northwell IRB registration number #22-0292 and U.S. Food and Drug Administration (FDA) Investigational New Drug (IND) approval has been granted under IND number 161609. Results are intended to be published in an open-source journal and further data, statistics and source documents are available on request. TRIAL REGISTRATION NUMBER: NCT05331131.

Does Size Matter? On the Role of Stereotactic Radiosurgery for Large Vestibular Schwannomas as Seen in an Institutional Experience of Gamma Knife Radiosurgery for High-Grade Tumors.

OBJECTIVE: Management of large vestibular schwannoma (VS) is controversial. Surgery has historically been the treatment of choice, but emerging literature suggests that definitive stereotactic radiosurgery is feasible. We report our institutional experience of control and morbidity outcomes treating Koos grade 3-4 VS with Gamma Knife radiosurgery (GKRS). METHODS: An institutional review board-approved database compiled outcomes of Koos grade 3-4 VS treated by GKRS from March 2014 to January 2021 with >6 months' follow-up. Baseline symptoms per Common Terminology Criteria for Adverse Events definitions were recorded. Control rates, toxicities, and post-treatment volumetric changes were analyzed. Aggregate impairment scores (AIs) were defined by the sum of relevant Common Terminology Criteria for Adverse Events grades to categorize symptomatic burdens. Baseline and post-treatment AIs were tested for association with definitive versus adjuvant strategies. RESULTS: In total, 34 patients with Koos grade 3-4 VS were identified, 19 treated with definitive GKRS (GKRS-D) and 15 with adjuvant GKRS (GKRS-A). Median follow-up was 34.2 months for GKRS-D and 48.8 months for GKRS-A. Patients who received GKRS-A had greater AIs at presentation (3.73 vs. 2.11, P = 0.017). Irrespective of treatment approach, tumor control rates were 100% without instances of brainstem necrosis or shunt placement. Six of 19 patients who received GKRS-D had improved post-treatment AI, and 63% of patients who received GKRS-D and 66% of patients who received GKRS-A had tumor shrinkage >20%. CONCLUSIONS: In well-selected patients with Koos grade 3-4 VS, definitive stereotactic radiosurgery may be an appropriate strategy with excellent control and minimal toxicity. Our data suggest that the need for surgical decompression should be considered based on pretreatment symptom burden rather than tumor size.

Impact of the COVID-19 Pandemic Surge on Radiation Treatment: Report From a Multicenter New York Area Institution.

PURPOSE: During the COVID-19 surge months of March and April 2020, our New York multicenter health system experienced an influx of cases with COVID-19. We sought to study the impact of the surge period on patients with cancer prescribed radiation treatment (RT). METHODS: We reviewed our secure departmental quality assurance database for all patients who underwent RT planning simulations from March 6, 2020, through April 30, 2020. A priority level between 1 and 3 was prospectively assigned to each case based on faculty consensus to determine which patients required immediate RT. In May 2020, each faculty physician again retrospectively reviewed their patients from the database and provided additional commentary on how the COVID-19 pandemic had affected each patient's care. All statistics are descriptive. RESULTS: A total of 412 RT courses in 406 unique patients were simulated for linear accelerator-based external beam RT. The median age was 66 years. Treatment intent was curative in 70.6% and palliative in 29.4%. Of the 412 cases, 66.7% were priority 1, 25% priority 2, and 7.8% priority 3. Two hundred thirty-nine cases (58%) underwent standard-of-care diagnosis, workup, and treatment plan. Seventeen patients (4.1%) electively canceled their RT, and 17 others (4.1%) electively delayed RT start. Thirty-four (8.3%) were prescribed hypofractionation to shorten their RT course, and 22 (5.3%) had a change in modality. Incomplete or delayed workup was identified in 19 cases (4.6%). CONCLUSION: The COVID-19 pandemic surge resulted in 42% of our patients having a non-standard-of-care pathway. This outcome demonstrates a significant impact of the COVID-19 crisis on routine cancer care.

Guidelines for Palliative Treatment of Spinal Metastases: Choosing Between Stereotactic Body Radiation Therapy and Conventional Fractionation.

Symptomatic spinal metastasis is a frequent complication of cancer that had been treated, until relatively recently, with primitive techniques to modest radiation dose levels, with a baseline assumption of limited survival and poor patient performance in that setting. In the era of targeted and personalized therapies, many patients are living longer and more functionally and are able to manage their disease on the model of chronic illness. Given these developments, an attractive option is the use of stereotactic body radiation therapy (SBRT) to deliver high biologically effective doses of radiation conformally to maximize the palliative gains of treatment. However, randomized data to guide practice are scarce. We review the extant literature and present an algorithmic approach to selecting patients with metastatic disease for palliative spinal SBRT favoring the results of available randomized studies and remaining within the safety constraints supported by evidence from randomized trials.

Stop hedging your bets: reasons for non-adherence to a tri-modality regimen in the treatment of esophageal cancer in a multidisciplinary setting.

BACKGROUND: In locally-advanced esophageal cancer (LAEC), providers' concerns regarding eventual surgical candidacy can persuade physicians to defer to definitive doses of 50 Gy or higher preoperatively. We report the successful completion rate of tri-modality therapy (TMT) (documented at the outset) and reasons for TMT non-adherence at a large multi-disciplinary esophageal program. METHODS: LAEC patients diagnosed 2007-2016 from a prospective institutional database were subdivided into CRT/S+ [completed chemoradiation (CRT) and surgery] and CRT/S- (CRT and no subsequent surgery) groups. Chart review provided surgery non-adherence reasons. RESULTS: A total of 283 patients met planned TMT criteria: 164 (58.0%) patients received 50 or 50.4 Gy CRT, 27 patients (9.5%) received greater than 50.4 Gy, and 92 patients received less than 50 Gy (32.5%, only 8 patients received CRT to 41.4 Gy); 221 (78.1%) completed surgery (CRT/S+), while 62 (21.9%) failed to advance to surgery (CRT/S-): 25 of 62 CRT/S- patients (40.3%) evidenced metastatic progression before surgery, 4 (6.5%) were deemed unresectable intraoperatively, 4 (6.5%) expired prior to planned surgery (3 from unknown causes, 1 suicide), 8 (12.9%) experienced significant CRT-related medical decompensation and were withdrawn from surgical consideration, 16 (25.8%) voluntarily declined surgery post-CRT (largely due to long-term quality of life concerns), and 5 (8.1%) failed to advance for unknown reasons. Four of the 16 patients who voluntarily declined surgery after CRT received less than 50 Gy. The 22.2% of CRT/S+ patients achieved pathologic complete response (21.6% for adenocarcinoma and 29.0% for squamous cell carcinoma). CONCLUSIONS: Our institution's 78% surgery completion rate among TMT-indicated patients highlights the benefits of upfront multidisciplinary care. Metastatic disease development most commonly truncated TMT with a low rate failing due to medical decompensation. Given the number of patients who voluntarily declined surgery following CRT, TMT counseling and involvement of a patient advocate are paramount prior to treatment planning.