Leptomeningeal metastases from solid tumors: A SNO and ASCO consensus review on clinical management and future directions

Leptomeningeal metastases are increasingly becoming recognized as a treatable, yet generally incurable, complication of advanced cancer. As modern cancer therapeutics have prolonged the lives of patients with metastatic cancer, specifically in patients with parenchymal brain metastases, treatment options and clinical research protocols for patients with leptomeningeal metastases from solid tumors have similarly evolved to improve survival within specific populations. Recent expansion in clinical investigation, early diagnosis, and drug development have given rise to new unanswered questions. These include leptomeningeal metastasis biology and preferred animal modeling, epidemiology in the modern cancer population, ensuring validation and accessibility of newer leptomeningeal metastasis diagnostics, best clinical practices with multi-modality treatment options, clinical trial design and standardization of response assessments, and avenues worthy of further research. An international group of multi-disciplinary experts in the research and management of leptomeningeal metastases, supported by the Society for Neuro-Oncology and American Society of Clinical Oncology, were assembled to reach a consensus opinion on these pressing topics and provide a roadmap for future directions. Our hope is that these recommendations will accelerate collaboration and progress in the field of leptomeningeal metastases and serve as a platform for further discussion and patient advocacy.

Prognostic value of cerebrospinal fluid tumor cell count in leptomeningeal disease from solid tumors

PURPOSE

Treatment decisions for leptomeningeal disease (LMD) rely on patient risk stratification, since clinicians lack objective prognostic tools. The introduction of rare cell capture technology for identification of cerebrospinal fluid tumor cells (CSF-TCs), such as CNSide assay, improved the sensitivity of LMD diagnosis, but prognostic value is unknown. This study assesses the prognostic value of CSF-TC density in patients with LMD from solid tumors.

METHODS

We conducted a retrospective cohort study of patients with newly diagnosed or previously treated LMD from a single institution who had CNSide assay testing for CSF-TCs from 2020 to 2023. Univariable and multivariable survival analyses were conducted with Cox proportional-hazards modeling. Maximally-selected rank statistics were used to determine an optimal cutpoint for CSF-TC density and survival.

RESULTS

Of 31 patients, 29 had CSF-TCs detected on CNSide. Median (interquartile range [IQR]) CSF-TC density was 67.8 (4.7-639) TCs/mL. CSF cytology was positive in 16 of 29 patients with positive CNSide (CNSide diagnostic sensitivity = 93.5%, negative predictive value = 85.7%). Median (IQR) survival from time of CSF-TC detection was 176 (89-481) days. On univariable and multivariable analysis, CSF-TC density was significantly associated with survival. An optimal cutpoint for dichotomizing survival by CSF-TC density was 19.34 TCs/mL. The time-dependent sensitivity and specificity for survival using this stratification were 76% and 67% at 6 months and 65% and 67% at 1 year, respectively.

CONCLUSIONS

CSF-TC density may carry prognostic value in patients with LMD from solid tumors. Integrating CSF-TC density into LMD patient risk-stratification may help guide treatment decisions.

Implementation Strategies to Promote Short-Course Radiation for Bone Metastases

Importance

For patients with nonspine bone metastases, short-course radiotherapy (RT) can reduce patient burden without sacrificing clinical benefit. However, there is great variation in uptake of short-course RT across practice settings.

Objective

To evaluate whether a set of 3 implementation strategies facilitates increased adoption of a consensus recommendation to treat nonspine bone metastases with short-course RT (ie, ≤5 fractions).

Design, Setting, and Participants

This prospective, stepped-wedge, cluster randomized quality improvement study was conducted at 3 community-based cancer centers within an existing academic-community partnership. Rollout was initiated in 3-month increments between October 2021 and May 2022. Participants included treating physicians and patients receiving RT for nonspine bone metastases. Data analysis was performed from October 2022 to May 2023.

Exposures

Three implementation strategies-(1) dissemination of published consensus guidelines, (2) personalized audit-and-feedback reports, and (3) an email-based electronic consultation platform (eConsult)-were rolled out to physicians.

Main Outcomes and Measures

The primary outcome was adherence to the consensus recommendation of short-course RT for nonspine bone metastases. Mixed-effects logistic regression at the bone metastasis level was used to model associations between the exposure of physicians to the set of strategies (preimplementation vs postimplementation) and short-course RT, while accounting for patient and physician characteristics and calendar time, with a random effect for physician. Physician surveys were administered before implementation and after implementation to assess feasibility, acceptability, and appropriateness of each strategy.

Results

Forty-five physicians treated 714 patients (median [IQR] age at treatment start, 67 [59-75] years; 343 women [48%]) with 838 unique nonspine bone metastases during the study period. Implementing the set of strategies was not associated with use of short-course RT (odds ratio, 0.78; 95% CI, 0.45-1.34; P = .40), with unadjusted adherence rates of 53% (444 lesions) preimplementation vs 56% (469 lesions) postimplementation; however, the adjusted odds of adherence increased with calendar time (odds ratio, 1.68; 95% CI, 1.20-2.36; P = .003). All 3 implementation strategies were perceived as being feasible, acceptable, and appropriate; only the perception of audit-and-feedback appropriateness changed before vs after implementation (19 of 29 physicians [66%] vs 27 of 30 physicians [90%]; P = .03, Fisher exact test), with 20 physicians (67%) preferring reports quarterly.

Conclusions and Relevance

In this quality improvement study, a multicomponent set of implementation strategies was not associated with increased use of short-course RT within an academic-community partnership. However, practice improved with time, perhaps owing to secular trends or physician awareness of the study. Audit-and-feedback was more appropriate than anticipated. Findings support the need to investigate optimal approaches for promoting evidence-based radiation practice across settings.

Radiation Therapy in the Management of Leptomeningeal Disease From Solid Tumors

Purpose

Leptomeningeal disease (LMD) is clinically detected in 5% to 10% of patients with solid tumors and is a source of substantial morbidity and mortality. Prognosis for this entity remains poor and treatments are palliative. Radiation therapy (RT) is an essential tool in the management of LMD, and a recent randomized trial demonstrated a survival benefit for proton craniospinal irradiation (CSI) in select patients. In the setting of this recent advance, we conducted a review of the role of RT in LMD from solid tumors to evaluate the evidence basis for RT recommendations.

Methods and Materials

In November 2022, we conducted a comprehensive literature search in PubMed, as well as a review of ongoing clinical trials listed on ClinicalTrials.gov, to inform a discussion on the role of RT in solid tumor LMD. Because of the paucity of high-quality published evidence, discussion was informed more by expert consensus and opinion, including a review of societal guidelines, than evidence from clinical trials.

Results

Only 1 prospective randomized trial has evaluated RT for LMD, demonstrating improved central nervous system progression-free survival for patients with breast and lung cancer treated with proton CSI compared with involved-field RT. Modern photon CSI techniques have improved upon historical rates of acute hematologic toxicity, but the overall benefit of this modality has not been prospectively evaluated. Multiple retrospective studies have explored the use of involved-field RT or the combination of RT with chemotherapy, but clear evidence of survival benefit is lacking.

Conclusions

Optimal management of LMD with RT remains reliant upon expert opinion, with proton CSI indicated in patients with good performance status and extra-central nervous system disease that is either well-controlled or for which effective treatment options are available. Photon-based CSI traditionally has been associated with increased marrow and gastrointestinal toxicities, though intensity modulated RT/volumetric-modulated arc therapy based photon CSI may have reduced the toxicity profile. Further work is needed to understand the role of radioisotopes as well as combined modality treatment with intrathecal or central nervous system penetrating systemic therapies.

Standard-of-care systemic therapy with or without stereotactic body radiotherapy in patients with oligoprogressive breast cancer or non-small-cell lung cancer (Consolidative Use of Radiotherapy to Block [CURB] oligoprogression): an open-label, randomised, controlled, phase 2 study

BACKGROUND

Most patients with metastatic cancer eventually develop resistance to systemic therapy, with some having limited disease progression (ie, oligoprogression). We aimed to assess whether stereotactic body radiotherapy (SBRT) targeting oligoprogressive sites could improve patient outcomes.

METHODS

We did a phase 2, open-label, randomised controlled trial of SBRT in patients with oligoprogressive metastatic breast cancer or non-small-cell lung cancer (NSCLC) after having received at least first-line systemic therapy, with oligoprogression defined as five or less progressive lesions on PET-CT or CT. Patients aged 18 years or older were enrolled from a tertiary cancer centre in New York, NY, USA, and six affiliated regional centres in the states of New York and New Jersey, with a 1:1 randomisation between standard of care (standard-of-care group) and SBRT plus standard of care (SBRT group). Randomisation was done with a computer-based algorithm with stratification by number of progressive sites of metastasis, receptor or driver genetic alteration status, primary site, and type of systemic therapy previously received. Patients and investigators were not masked to treatment allocation. The primary endpoint was progression-free survival, measured up to 12 months. We did a prespecified subgroup analysis of the primary endpoint by disease site. All analyses were done in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT03808662, and is complete.

FINDINGS

From Jan 1, 2019, to July 31, 2021, 106 patients were randomly assigned to standard of care (n=51; 23 patients with breast cancer and 28 patients with NSCLC) or SBRT plus standard of care (n=55; 24 patients with breast cancer and 31 patients with NSCLC). 16 (34%) of 47 patients with breast cancer had triple-negative disease, and 51 (86%) of 59 patients with NSCLC had no actionable driver mutation. The study was closed to accrual before reaching the targeted sample size, after the primary efficacy endpoint was met during a preplanned interim analysis. The median follow-up was 11·6 months for patients in the standard-of-care group and 12·1 months for patients in the SBRT group. The median progression-free survival was 3·2 months (95% CI 2·0-4·5) for patients in the standard-of-care group versus 7·2 months (4·5-10·0) for patients in the SBRT group (hazard ratio [HR] 0·53, 95% CI 0·35-0·81; p=0·0035). The median progression-free survival was higher for patients with NSCLC in the SBRT group than for those with NSCLC in the standard-of-care group (10·0 months [7·2-not reached] vs 2·2 months [95% CI 2·0-4·5]; HR 0·41, 95% CI 0·22-0·75; p=0·0039), but no difference was found for patients with breast cancer (4·4 months [2·5-8·7] vs 4·2 months [1·8-5·5]; 0·78, 0·43-1·43; p=0·43). Grade 2 or worse adverse events occurred in 21 (41%) patients in the standard-of-care group and 34 (62%) patients in the SBRT group. Nine (16%) patients in the SBRT group had grade 2 or worse toxicities related to SBRT, including gastrointestinal reflux disease, pain exacerbation, radiation pneumonitis, brachial plexopathy, and low blood counts.

INTERPRETATION

The trial showed that progression-free survival was increased in the SBRT plus standard-of-care group compared with standard of care only. Oligoprogression in patients with metastatic NSCLC could be effectively treated with SBRT plus standard of care, leading to more than a four-times increase in progression-free survival compared with standard of care only. By contrast, no benefit was observed in patients with oligoprogressive breast cancer. Further studies to validate these findings and understand the differential benefits are warranted.

FUNDING

National Cancer Institute.

Craniospinal irradiation for CNS leukemia: rates of response and durability of CNS control

PURPOSE

Management of CNS involvement in leukemia may include craniospinal irradiation (CSI), though data on CSI efficacy are limited.

METHODS

We retrospectively reviewed leukemia patients who underwent CSI at our institution between 2009 and 2021 for CNS involvement. CNS local recurrence (CNS-LR), any recurrence, progression-free survival (PFS), CNS PFS, and overall survival (OS) were estimated.

RESULTS

Of thirty-nine eligible patients treated with CSI, most were male (59%) and treated as young adults (median 31 years). The median dose was 18 Gy to the brain and 12 Gy to the spine. Twenty-five (64%) patients received CSI immediately prior to allogeneic hematopoietic cell transplant, of which 21 (84%) underwent total body irradiation conditioning (median 12 Gy). Among 15 patients with CSF-positive disease immediately prior to CSI, all 14 assessed patients had pathologic clearance of blasts (CNS-response rate 100%) at a median of 23 days from CSI start. With a median follow-up of 48 months among survivors, 2-year PFS and OS were 32% (95% CI 18-48%) and 43% (95% CI 27-58%), respectively. Only 5 CNS relapses were noted (2-year CNS-LR 14% (95% CI 5-28%)), which occurred either concurrently or after a systemic relapse. Only systemic relapse after CSI was associated with higher risk of CNS-LR on univariate analysis. No grade 3 or higher acute toxicity was seen during CSI.

CONCLUSION

CSI is a well-tolerated and effective treatment option for patients with CNS leukemia. Control of systemic disease after CSI may be important for CNS local control. CNS recurrence may reflect reseeding from the systemic space.

Prophylactic Radiation Therapy Versus Standard of Care for Patients With High-Risk Asymptomatic Bone Metastases: A Multicenter, Randomized Phase II Clinical Trial

PURPOSE

External-beam radiation therapy (RT) is standard of care (SOC) for pain relief of symptomatic bone metastases. We aimed to evaluate the efficacy of radiation to asymptomatic bone metastases in preventing skeletal-related events (SRE).

METHODS

In a multicenter randomized controlled trial, adult patients with widely metastatic solid tumor malignancies were stratified by histology and planned SOC (systemic therapy or observation) and randomly assigned in a 1:1 ratio to receive RT to asymptomatic high-risk bone metastases or SOC alone. The primary outcome of the trial was SRE. Secondary outcomes included hospitalizations for SRE and overall survival (OS).

RESULTS

A total of 78 patients with 122 high-risk bone metastases were enrolled between May 8, 2018, and August 9, 2021, at three institutions across an affiliated cancer network in the United States. Seventy-three patients were evaluable for the primary end point. The most common primary cancer types were lung (27%), breast (24%), and prostate (22%). At 1 year, SRE occurred in one of 62 bone metastases (1.6%) in the RT arm and 14 of 49 bone metastases (29%) in the SOC arm (P < .001). There were significantly fewer patients hospitalized for SRE in the RT arm compared with the SOC arm (0 v 4, P = .045). At a median follow-up of 2.5 years, OS was significantly longer in the RT arm (hazard ratio [HR], 0.49; 95% CI, 0.27 to 0.89; P = .018), which persisted on multivariable Cox regression analysis (HR, 0.46; 95% CI, 0.23 to 0.85; P = .01).

CONCLUSION

Radiation delivered prophylactically to asymptomatic, high-risk bone metastases reduced SRE and hospitalizations. We also observed an improvement in OS with prophylactic radiation, although a confirmatory phase III trial is warranted.

Leptomeningeal Carcinomatosis from Solid Tumor Malignancies: Treatment Strategies and Biomarkers

Leptomeningeal metastases/diseases (LMDs) are a late-stage complication of solid tumor or hematologic malignancies. LMD is spread of cancer cells to the layers of the leptomeninges (pia and arachnoid maters) and subarachnoid space seen in 3 to 5% of cancer patients. It is a disseminated disease which carries with it significant neurologic morbidity and mortality. Our understanding of disease pathophysiology is currently lacking; however, advances are being made. As our knowledge of disease pathogenesis has improved, treatment strategies have evolved. Mainstays of treatment such as radiotherapy have changed from involved-field radiotherapy strategies to proton craniospinal irradiation which has demonstrated promising results in recent clinical trials. Systemic treatment strategies have also improved from more traditional chemotherapeutics with limited central nervous system (CNS) penetration to more targeted therapies with better CNS tumor response. Many challenges remain from earlier clinical detection of disease through improvement of active treatment options, but we are getting closer to meaningful treatment.

Emergent radiotherapy for brain and leptomeningeal metastases: a narrative review

BACKGROUND AND OBJECTIVE

As novel systemic therapies allow patients to live longer with cancer, the risk of developing central nervous system (CNS) metastases increases and providers will more frequently encounter emergent presentation of brain metastases (BM) and leptomeningeal metastases (LM). Management of these metastases requires appropriate work-up and well-coordinated multidisciplinary care. We set out to perform a review of emergent radiotherapy (RT) for CNS metastases, specifically focusing on BM and LM.

METHODS

We review the appropriate pathways for workup and initial management of BM and LM, while reviewing the literature supporting emergent treatment of these entities with surgery, systemic anti-cancer therapy, and RT. To inform this narrative review, literature searches in PubMed and Google Scholar were conducted, with preference given to articles employing modern RT techniques, when applicable. Due to the paucity of high-quality evidence for management of BM and LM in the emergent setting, discussion was supplemented by the authors' expert commentary.

KEY CONTENT AND FINDINGS

This work highlights the importance of surgical evaluation, particularly for patients presenting with significant mass effect, hemorrhagic metastases, or increased intracranial pressure. We review the rare situations where emergent initiation of systemic anti-cancer therapy is indicated. When defining the role of RT, we review factors guiding selection of appropriate modality, treatment volume, and dose-fractionation. Generally, 2D- or 3D-conformal treatment techniques prescribed as 30 Gy in 10 fractions or 20 Gy in 5 fractions, should be employed in the emergent setting.

CONCLUSIONS

Patients with BM and LM present from a diverse array of clinical situations, requiring well-coordinated multidisciplinary management, and there is a paucity of high-quality evidence guiding such management decisions. This narrative review aims to more thoroughly prepare providers for the challenging situation of emergent management of BM and LM.

Study on physicochemical properties, fatty acids, texture, antioxidant and antibacterial activities of ghee from different regions

Due to the lack of basic information on Chinese ghee and the increasing demand of consumers for natural oils, this study aims to explore and distinguish the quality characteristics of ghee in different regions of China. Ghee samples from 16 regions of Qinghai Province, Gansu Province, Xinjiang Uyghur Autonomous Region, and Tibet Autonomous Region were selected and their physicochemical properties, fatty acids, texture, antioxidant and antibacterial activities were determined. The results showed that: (1) The physicochemical properties of ghee were different from different regions, but the freshness and fat content are generally high. The results of iodine value and saponification value suggest that the fatty acid composition is good; (2) The unsaturated fatty acid/saturated fatty acid content of ghee in Tibet and Xinjiang ranges from 63.05% to 79.13%, which is better than that in other regions; (3) Gansu Diebu ghee has the highest hardness (40.69 N); (4) Ghee from different regions has good antioxidant activity, DPPH free radical scavenging activity is 30.45% to 58.06%, ABTS free radical scavenging activity is 41.14% to 65.53%, and has varying degrees of inhibition on gram-positive bacteria. In addition, yak ghee, cattle-yak ghee and cow ghee have better fatty acid composition and antibacterial ability than scalper ghee. The results of this study distinguish the differences in the quality characteristics of yak ghee in different geographical regions. Therefore, it can provide a theoretical basis for the origin tracing and quality-oriented improvement of yak ghee.

Emergent radiotherapy for spinal cord compression/impingement-a narrative review

BACKGROUND AND OBJECTIVE

Malignant epidural spinal cord compression (MESCC), often presenting with back pain and motor/sensory deficits, is associated with poor survival, particularly when there is loss of ambulation. The purpose of this review is to evaluate the literature and discuss appropriate workup and management of MESCC, specifically in the emergent setting.

METHODS

A PubMed search was conducted on "spinal cord compression" and "radiation therapy." Articles were analyzed for the purpose of this narrative review.

KEY CONTENT AND FINDINGS

If MESCC is suspected, neurologic examination and complete spine imaging are recommended. Emergent treatment is indicated if there is radiographic evidence of high-grade compression and/or clinically significant motor deficits. Treatment involves a combination of medical management, surgical decompression, radiation therapy (RT), and rehabilitation. For motor deficits, emergent initiation of high dose steroids is recommended. Circumferential surgical decompression ± stabilization followed by RT provides superior clinical outcomes than RT alone. For patients whom surgery is not reasonable, RT alone may provide significant treatment response which depends on radioresponsiveness of the pathology. Systemic therapy, if indicated, is typically reserved till after primary treatment of MESCC, but patients with chemoresponsive tumors may receive primary chemotherapy. The selected RT schedule should be personalized to each patient and commonly is 30 Gy in 10 fractions (fx), 20 Gy in 5 fx, or 8 Gy in 1 fx. MESCC recurrence may be treated with additional RT, if within the spinal cord tolerance, or surgery. Stereotactic body radiation therapy (SBRT) has been used for high grade MESCC in patients with relatively intact neurologic function at a few centers with a very robust infrastructure to support rapid initiation of treatment within a short period of time, but is generally not feasible for most clinical practices. SBRT may be advantageous for low grade MESCC, recurrence, or in the post-operative setting. Detection of MESCC prior to development of high-grade compression or deterioration of neurologic function may allow patients to benefit more from advanced therapies and improve prognosis.

CONCLUSIONS

MESCC is a devastating condition; optimal treatment should be personalized to each patient and approached collaboratively by a multidisciplinary team.

Dosimetric Impact of Radiolucent Carbon Fiber Hardware for Post-Operative Spine Stereotactic Body Radiation Therapy

PURPOSE/OBJECTIVE(S)

The spine is the most common site of osseous metastases. In the non-operative setting, there is growing support for stereotactic body radiation therapy (SBRT) over conventional radiation therapy for improved pain relief and local control. Hybrid therapy consisting of separation surgery and post-operative SBRT is considered in patients with biomechanical instability and epidural cord compression. Surgery traditionally requires titanium (Ti) implants, which introduce artifacts on post-operative imaging in addition to increased uncertainty and beam attenuation. Use of radiolucent carbon fiber reinforced polyetheretherketone (CFR-PEEK) hardware has been shown to provide safe and comparable surgical outcomes as compared to Ti. Our primary objective is to assess the dosimetric impact of Ti versus carbon fiber implants in spine SBRT.

MATERIALS/METHODS

Single institution retrospective series of post-operative spine SBRT from 2019-2020. Re-irradiation cases were excluded. The electronic medical record and treatment planning systems (TPS) were queried. Dosimetric analyses compared original Ti plans with reoptimized plans, replacing Ti hardware electronic density with carbon fiber. Maintaining clinical goals, dose calculations were performed in a treatment planning system using a collapsed cone algorithm. All treatments used step and shoot intensity modulated radiation therapy to avoid beam angles with significant metal along the beam path. Metallic artifacts were contoured and assigned the appropriate tissue density. A D'Agostino-Pearson test was used to assess data for normality. We used paired Student's t-tests to compare three dosimetric outcomes in the setting of Ti and carbon fiber implants. Planning target volume (PTV) coverage was represented by the volume receiving at least the prescribed dose (%), the maximum point dose (dmax, cGy) to the spinal cord planning risk volume (PRV, 2 mm margin), and the overall hot spot intensity (plan dmax).

RESULTS

A series of 14 consecutive SBRT cases were evaluated (dose 27-30 Gy in 3-5 fractions). All dosimetric outcomes were normally distributed (p>0.05). We found a statistically significant difference in PTV coverage between the original SBRT treatment plans with Ti hardware (mean 85.1 ± 7.9%) and reoptimized carbon fiber hardware (87.3 ± 6.6%; p = 0.002). There was no significant difference in mean spinal cord PRV dmax between Ti and carbon fiber plans (1846 ± 483 cGy vs. 1842 ± 495 cGy; p>0.05). We observed a nonsignificant increase in mean overall dmax from 3932 ± 416 cGy in the Ti cohort to 4111 ± 906 cGy in the carbon fiber cohort (p>0.05).

CONCLUSION

Carbon fiber implants provide a significant increase in SBRT target coverage, without impacting the overall plan and spinal cord PRV dmax in this retrospective series. In addition to improved post-operative imaging and reduced uncertainty, carbon fiber hardware may offer dosimetric advantages as compared to traditional Ti spinal implants, and warrants further investigation in a larger cohort.

Craniospinal Irradiation for CNS Leukemia: Rates of Response and Durability of CNS Control

PURPOSE/OBJECTIVE(S)

Craniospinal irradiation (CSI) is used in the management of leukemia patients with central-nervous-system (CNS) involvement, though the data on response and local control are limited. Given the radioresponsiveness of leukemia, we hypothesized that response to CSI would be high, but CNS control would be influenced by control of systemic disease.

MATERIALS/METHODS

This retrospective, single-institution analysis included consecutive pediatric and adult patients between 2009-2021 with leukemia that underwent CSI for CNS involvement, defined as presence of blasts (i.e., >0%) on CSF flow cytometry. Endpoints included CNS response rate (RR), CNS local recurrence (LR), progression-free survival (PFS), and overall survival (OS), which were estimated from start of CSI. The probability of CNS LR was summarized using a cumulative incidence estimate, where death without LR was considered a competing risk. The probabilities of OS and PFS were obtained using Kaplan-Meier estimates.

RESULTS

Among the 39 eligible patients (43% AML, 49% ALL, 8% blast-phase CML), most were male (59%). All had CSF confirmation of disease. Median age at CSI was 31 years (range 7-67). CSI (protons 54%, photons 46%) was utilized early within the CNS disease course (median 0 CNS relapses prior to CSI). Twenty-five patients (64%) received CSI immediately prior to a stem-cell transplant (SCT), of which 21 (84%) had TBI conditioning to a median dose of 12 Gy (range 2-13.2). Patients treated with CSI alone received a higher CSI dose (median 18 Gy; range 10.8-24) than those treated with SCT consolidation (median 12 Gy; range 10.8-24). Fifteen patients had CSF-positive disease immediately prior to CSI; all 14 of those assessed for response (RR 100%) had confirmed clearance of blasts at a median of 23 days (range 7-197) from CSI start. With a median follow-up of 48 months (range 0.4-123) for survivors, 2-year PFS and OS estimates were 32% and 43%, respectively. Only 5 CNS relapses were noted (2-year CNS LR of 14%). All CNS relapses either occurred after (n = 4) or concurrently (n = 1) with a systemic relapse. In Cox regression univariate models, age, sex, time to CNS disease, positive CSF immediately prior to CSI, and SCT did not show demonstrable evidence of association with CNS LR. However, systemic relapse after CSI (HR 5.9, 95% CI 2.5-13.8, P<0.0001) and systemic disease at the time of CSI (HR 3.9, 95% CI 1.6-9.5, P = 0.003) were associated with higher risk of CNS LR. No grade-3+ acute toxicity was seen during CSI.

CONCLUSION

CSI is a well-tolerated and effective treatment option for patients with CNS leukemia. Though CNS local recurrence was modest, there was a high risk of systemic relapse and/or death. Control of systemic disease, both before and after CSI, may be important for CNS local control, and raises consideration that CNS recurrence may reflect reseeding from the systemic space.

Implementation Outcomes of Strategies to Promote Short-Course Radiation for Nonspine Bone Metastases in an Academic-Community Partnership: Survey Results from the ALIGNMENT Trial

PURPOSE/OBJECTIVE(S)

Local treatment of nonspine bone metastases has become increasingly complex, resulting in physician practice variability nationwide. The purpose of this study was to assess physician perceptions of 3 implementation strategies to promote adoption of short course radiotherapy (RT) for nonspine bone metastases.

MATERIALS/METHODS

ALIGNMENT ("Alliance Group for Bone Metastasis") was a multi-institutional stepped wedge cluster randomized implementation trial testing strategies to increase use of ≤5 fractions for nonspine bone metastases conducted across 3 clinical sites in an academic-community partnership. Strategies included a) multidisciplinary consensus guidelines, b) e-Consults, an email-based consultation platform, and c) personalized audit and feedback (A&F) reports with peer comparison. Using the Proctor et al. framework and validated questions from Weiner et al., physician surveys were used to assess each strategy's usefulness, acceptability (i.e., "I welcome [strategy]"), appropriateness (i.e., "[strategy] seems like a good match"), and feasibility (i.e., "[strategy] seems implementable" or "easy to use"). Survey responses were anonymized, so Fisher's Exact test was used to compare proportions with significance set at p<0.05.

RESULTS

Overall, 29 of 38 and 30 of 38 physicians participated in the pre- and post-implementation surveys, respectively, with 80% completing both. Pre-implementation, guidelines was most often ranked 1st in terms of usefulness (61%), followed by eConsults (38%) and A&F (3%). Post-implementation, guidelines and eConsults had the most and least favorable acceptability, appropriateness, and feasibility scores, respectively (Table), with 77% of physicians being likely to recommend the guidelines to other oncologists. In contrast, while 43% of physicians reported having at least 1 difficult clinical question regarding bone metastases during the study, only 33% of physicians preferred eConsults, while 50% preferred reaching out to a friend/colleague. Lastly, although A&F had the lowest perceived usefulness pre-implementation, A&F had the greatest increase in acceptability (72%→90%; p = 0.10), appropriateness (66%→90%; p = 0.03) feasibility ("implementable": 59%→93%, p = 0.002; "easy to use": 45%→93%, p<0.001).

CONCLUSION

In this multicenter trial, all strategies were acceptable, appropriate, and feasible, with guidelines and A&F showing the most favorable outcomes post-implementation. While guidelines were assessed as the most useful, A&F had significant increases in appropriateness and feasibility.

A Worksheet to Facilitate Discussions of Values for Patients With Metastatic Cancer: A Pilot Study

CONTEXT

Individual goals and values should drive medical decision making for patients with serious illness. Unfortunately, clinicians' existing strategies to encourage reflection and communication regarding patients' personal values are generally time-consuming and limited in scope.

OBJECTIVES

Herein, we develop a novel intervention to facilitate at-home reflection and discussion about goals and values. We then conduct a pilot study of our intervention in a small population of patients with metastatic cancer.

METHODS

We first engaged former cancer patients and their families to adapt an existing serious illness communication guide to a worksheet format. We then distributed this adapted "Values Worksheet" to 28 patients with metastatic cancer. We surveyed participants about their perceptions of the Worksheet to assess its feasibility.

RESULTS

Of 30 patients approached, 28 agreed to participate. Seventeen participants completed the Values Worksheet, and of those 11 (65%) responded to the follow-up survey. Seven of eleven reported that the Values Worksheet was a good use of time, and nine of eleven would be likely to recommend it to other patients with cancer. Eight of ten reported mild distress, two of ten reported moderate to severe distress.

CONCLUSION

The Values Worksheet was a feasible way to facilitate at-home discussions of goals and values for select patients with metastatic cancer. Further research should focus on identifying which patients are most likely to benefit from the Values Worksheet, and should employ the Worksheet as one tool to facilitate reflection on the questions that arise around serious illness, as an adjunct to serious illness conversations with a physician.

Early Detection of Leptomeningeal Metastases Among Patients Undergoing Spinal Stereotactic Radiosurgery

Purpose

The management of patients with advanced solid malignancies increasingly uses stereotactic body radiation therapy (SBRT). Advanced cancer patients are at risk for developing leptomeningeal metastasis (LM), a fatal complication of metastatic cancer. Cerebrospinal fluid (CSF) is routinely collected during computed tomography (CT) myelography for spinal SBRT planning, offering an opportunity for early LM detection by CSF cytology in the absence of radiographic LM or LM symptoms (subclinical LM). This study tested the hypothesis that early detection of tumor cells in CSF in patients undergoing spine SBRT portends a similarly poor prognosis compared with clinically overt LM.

Methods and Materials

We retrospectively analyzed clinical records for 495 patients with metastatic solid tumors who underwent CT myelography for spinal SBRT planning at a single institution from 2014 to 2019.

Results

Among patients planned for SBRT, 51 (10.3%) developed LM. Eight patients (1.6%) had subclinical LM. Median survival with LM was similar between patients with subclinical versus clinically evident LM (3.6 vs 3.0 months, P = .30). Patients harboring both parenchymal brain metastases and LM (29/51) demonstrated shorter survival than those with LM alone (2.4 vs 7.1 months, P = .02).

Conclusions

LM remains a fatal complication of metastatic cancer. Subclinical LM detected by CSF cytology in spine SBRT patients has a similarly poor prognosis compared with standardly detected LM and warrants consideration of central nervous system-directed therapies. As aggressive local therapies are increasingly used for metastatic patients, more sensitive CSF evaluation may further identify patients with subclinical LM and should be evaluated prospectively.

Dynamic Mutational Landscape of Cerebrospinal Fluid Circulating Tumor DNA and Predictors of Survival after Proton Craniospinal Irradiation for Leptomeningeal Metastases

PURPOSE

Proton craniospinal irradiation (pCSI) is a promising treatment for patients with solid tumor leptomeningeal metastasis (LM). We hypothesize that genetic characteristics before and changes resulting after pCSI will reflect clinical response to pCSI. We analyzed the cerebrospinal fluid (CSF) circulating tumor DNA (ctDNA) from patients receiving pCSI for LM and explored genetic variations associated with response.

EXPERIMENTAL DESIGN

We subjected CSF from 14 patients with LM before and after pCSI to cell-free DNA sequencing using a targeted-sequencing panel. In parallel, plasma ctDNA and primary tumors were subjected to targeted sequencing. Variant allele frequency (VAF) and cancer cell fraction (CCF) were calculated; clonality of observed mutations was determined. Kaplan-Meier analysis was used to associate genomic changes with survival.

RESULTS

The median overall survival (OS) for the cohort was 9 months [interquartile range (IQR), 5-21 months]. We showed clonal evolution between tumor and ctDNA of the CSF and plasma with unique mutations identified by compartment. Higher CSF ctDNA mean VAF before pCSI (VAFpre) had worse OS (6 months for VAFpre ≥ 0.32 vs. 9 months for VAFpre < 0.32; P = 0.05). Similarly, increased VAF after pCSI portended worse survival (6 vs. 18 months; P = 0.008). Higher mean CCF of subclonal mutations appearing after pCSI was associated with worse OS (8 vs. 17 months; P = 0.05).

CONCLUSIONS

In patients with solid tumor LM undergoing pCSI, we found unique genomic profiles associated with pCSI through CSF ctDNA analyses. Patients with reduced genomic diversity within the leptomeningeal compartment demonstrated improved OS after pCSI suggesting that CSF ctDNA analysis may have use in predicting pCSI response.

Radiomic Analysis to Predict Histopathologically Confirmed Pseudoprogression in Glioblastoma Patients

Purpose

Pseudoprogression mimicking recurrent glioblastoma remains a diagnostic challenge that may adversely confound or delay appropriate treatment or clinical trial enrollment. We sought to build a radiomic classifier to predict pseudoprogression in patients with primary isocitrate dehydrogenase wild type glioblastoma.

Methods and Materials

We retrospectively examined a training cohort of 74 patients with isocitrate dehydrogenase wild type glioblastomas with brain magnetic resonance imaging including dynamic contrast enhanced T1 perfusion before resection of an enhancing lesion indeterminate for recurrent tumor or pseudoprogression. A recursive feature elimination random forest classifier was built using nested cross-validation without and with O⁶-methylguanine-DNA methyltransferase status to predict pseudoprogression.

Results

A classifier constructed with cross-validation on the training cohort achieved an area under the receiver operating curve of 81% for predicting pseudoprogression. This was further improved to 89% with the addition of O⁶-methylguanine-DNA methyltransferase status into the classifier.

Conclusions

Our results suggest that radiomic analysis of contrast T1-weighted images and magnetic resonance imaging perfusion images can assist the prompt diagnosis of pseudoprogression. Validation on external and independent data sets is necessary to verify these advanced analyses, which can be performed on routinely acquired clinical images and may help inform clinical treatment decisions.

Randomized Phase II Trial of Proton Craniospinal Irradiation Versus Photon Involved-Field Radiotherapy for Patients With Solid Tumor Leptomeningeal Metastasis

PURPOSE

Photon involved-field radiotherapy (IFRT) is the standard-of-care radiotherapy for patients with leptomeningeal metastasis (LM) from solid tumors. We tested whether proton craniospinal irradiation (pCSI) encompassing the entire CNS would result in superior CNS progression-free survival (PFS) compared with IFRT.

PATIENTS AND METHODS

We conducted a randomized, phase II trial of pCSI versus IFRT in patients with non-small-cell lung cancer and breast cancers with LM. We enrolled patients with other solid tumors to an exploratory pCSI group. For the randomized groups, patients were assigned (2:1), stratified by histology and systemic disease status, to pCSI or IFRT. The primary end point was CNS PFS. Secondary end points included overall survival (OS) and treatment-related adverse events (TAEs).

RESULTS

Between April 16, 2020, and October 11, 2021, 42 and 21 patients were randomly assigned to pCSI and IFRT, respectively. At planned interim analysis, a significant benefit in CNS PFS was observed with pCSI (median 7.5 months; 95% CI, 6.6 months to not reached) compared with IFRT (2.3 months; 95% CI, 1.2 to 5.8 months; P < .001). We also observed OS benefit with pCSI (9.9 months; 95% CI, 7.5 months to not reached) versus IFRT (6.0 months; 95% CI, 3.9 months to not reached; P = .029). There was no difference in the rate of grade 3 and 4 TAEs (P = .19). In the exploratory pCSI group, 35 patients enrolled, the median CNS PFS was 5.8 months (95% CI, 4.4 to 9.1 months) and OS was 6.6 months (95% CI, 5.4 to 11 months).

CONCLUSION

Compared with photon IFRT, we found pCSI improved CNS PFS and OS for patients with non-small-cell lung cancer and breast cancer with LM with no increase in serious TAEs.

[Progress in epidemiological research of 2019-nCoV infection and COVID-19 vaccination in pregnancy]

Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by 2019-nCoV. Due to the physiological change in pregnancy, pregnant women are susceptible to COVID-19 and are at increased risk for adverse pregnancy outcomes, especially in the context of spread of novel variants. At present, less evidences have been obtained from randomized controlled trials on the effectiveness and safety of COVID-19 vaccine use in pregnant women, and the recommendations of COVID-19 vaccination for pregnant women vary with countries, posing challenge to the prevention and control of COVID-19 in pregnant women. This paper summarizes the progress in major research of 2019-nCoV infection in pregnancy conducted both at home and abroad, describes the harm of COVID-19 in pregnancy to pregnant women, fetuses and infants and introduces the effectiveness and safety of COVID-19 vaccination in pregnancy revealed by real world studies in order to provide reference for the related research and development of COVID-19 prevention and control strategies in pregnant women.

LOCL-15 PERMANENT CARRIER-EMBEDDED CESIUM-131 BRACHYTHERAPY FOR THE SALVAGE TREATMENT OF PREVIOUSLY IRRADIATED, RECURRENT BRAIN METASTASES

BACKGROUND

Salvage of recurrent of previously-irradiated brain metastases (rBrM) is a significant clinical challenge. High local failure rates are seen following salvage resection without adjuvant re-irradiation, while reirradiation is associated with high radionecrosis rates. Salvage surgery plus intraoperative Cs131 brachytherapy may offer dosimetric and biologic advantages including improved local control versus observation, with reduced integral brain dose versus re-irradiation.

METHODS

A prospective registry of consecutively treated patients with rBrM after prior stereotactic radiosurgery (SRS) was analyzed. Following maximal-safe resection and intraoperative viable-disease confirmation, cavities were implanted with commercially-available, collagen-matrix embedded Cs131 seeds (GammaTile, GT Medical Technologies). Prescribed dose was 60Gy at 5mm from the cavity.

RESULTS

Twenty patients underwent 24 operations with Cs131 implantation in 25 cavities. Previous SRS occurred a median of 358d preoperatively (range=56-1334). Median maximum preoperative diameter was 3.0cm (range=1.1-6.3) and enhancing volume was 9.5cm3 (range=0.6-69.7). Gross- or near-total resection was achieved in 60% of lesions. A median of 16 Cs131 seeds (range=6-30), with a median activity of 3.5U/seed were implanted. Maximal preoperative diameter and enhancing volume were weakly associated with the number of implanted seeds (correlation coefficients=0.50, 0.41, respectively). There was one postoperative wound dehiscence in a multiply resected and irradiated patient with hydrocephalus. With median follow-up of 12.5 months, 2 tumors recurred (one in-field, one marginal) resulting in a 1-year progression incidence of 9.8% (95%CI=0.0-23.2). Radiographic seed migration was identified in 7/25 cavities (28%) on surveillance scans ranging from 1.9-11.7 months post-implantation, without clinical sequelae.

CONCLUSIONS

With &gt;1 year of follow-up, intraoperative brachytherapy with commercially-available Cs131 implants was associated with a high rate of local control and a favorable toxicity profile. Modest correlation between preoperative tumor geometry and implanted tiles in the context of high associated cost suggests a need to optimize planning criteria. A randomized trial of salvage resection with or without Cs131 is ongoing (NCT04690348) to assess the incremental benefit of brachytherapy.

Salvage resection plus cesium-131 brachytherapy durably controls post-SRS recurrent brain metastases

BACKGROUND

Salvage of recurrent previously irradiated brain metastases (rBrM) is a significant challenge. Resection without adjuvant re-irradiation is associated with a high local failure rate, while reirradiation only partially reduces failure but is associated with greater radiation necrosis risk. Salvage resection plus Cs131 brachytherapy may offer dosimetric and biologic advantages including improved local control versus observation, with reduced normal brain dose versus re-irradiation, however data are limited.

METHODS

A prospective registry of consecutive patients with post-stereotactic radiosurgery (SRS) rBrM undergoing resection plus implantation of collagen-matrix embedded Cs131 seeds (GammaTile, GT Medical Technologies) prescribed to 60 Gy at 5 mm from the cavity was analyzed.

RESULTS

Twenty patients underwent 24 operations with Cs131 implantation in 25 tumor cavities. Median maximum preoperative diameter was 3.0 cm (range 1.1-6.3). Gross- or near-total resection was achieved in 80% of lesions. A median of 16 Cs131 seeds (range 6-30), with a median air-kerma strength of 3.5 U/seed were implanted. There was one postoperative wound dehiscence. With median follow-up of 1.6 years for survivors, two tumors recurred (one in-field, one marginal) resulting in 8.4% 1-year progression incidence (95%CI = 0.0-19.9). Radiographic seed settling was identified in 7/25 cavities (28%) 1.9-11.7 months post-implantation, with 1 case of distant migration (4%), without clinical sequelae. There were 8 cases of radiation necrosis, of which 4 were symptomatic.

CONCLUSIONS

With > 1.5 years of follow-up, intraoperative brachytherapy with commercially available Cs131 implants was associated with favorable local control and toxicity profiles. Weak correlation between preoperative tumor geometry and implanted tiles highlights a need to optimize planning criteria.

HGG-35. Radiation Induced High Grade Gliomas: A Single Center Experience

INTRODUCTION: Patients receiving cranial radiotherapy (RT) are at risk for a subsequent radiation-induced glioma (RIG). RIGs are rare, generally develop with a latency of 2 years to several decades, display high-grade histology and an aggressive clinical course with poor prognosis. METHODS: We retrospectively analyzed patients with a diagnosis of RIG seen at our institution from 2001-2021, analyzing clinical, histological, molecular, and genetic characteristics. RESULTS: Twenty-one patients (n=15 male) with a history of ALL (n=6), medulloblastoma (n=5), germ cell tumors (n=4), or other (n=6) diagnosed at a median age of 8.3 years (range 1.6 to 36.4) were identified. Median age at RIG diagnosis was 18 years (range 7.8 to 66.9). Prior RT was focal+craniospinal (n=7), whole brain (n=5), total body (n=3), focal (n=1), or unknown (n=5). Median radiation dose received was 2,340 cGy (range 1,200 to 5,400). The median time from RT to RIG diagnosis was 7.7 years (range 1.6 to 23.8). All RIGs were histologically high grade (WHO Grade III or IV). Immunohistochemistry did not reveal IDH(R132H) (n=9) or H3K27M (n=8) in any tumor. Some tumors demonstrated loss of expression of ATRX (1/9) and/or H3K27me3 (3/6), and/or strong diffuse expression of p53 (0/3). Targeted panel sequencing (n=10) revealed recurrent somatic alterations including CDKN2A/B, PDGFRa/KIT/KDR, TEK, MTAP, ATM and NF1. Germline alterations were detected in 4/12 patients (pathogenetic variants in ATM, CHEK2, HOXB13 and NF1). With median follow-up of 4.5 years, two-year PFS and OS for the cohort (n=20) were 10% and 44% respectively. Two patients (with anaplastic oligodendroglioma and anaplastic astrocytoma) are alive without progression 5.4 and 13.6 years after diagnosis following surgery, RT and chemotherapy. CONCLUSION: Although RIGs are associated with a poor prognosis, they are not always fatal. Our findings suggest aggressive therapy should be considered for these patients.