Comprehensive craniospinal radiation for controlling central nervous system leukemia

Urgent and emergent radiotherapy for hematologic malignancies of the central nervous system: a review of the literature and practical approach

Introduction

Hematologic malignancies, including leukemias, lymphomas, and myeloma, can involve the central nervous system (CNS) at the time of diagnosis or later in relapse. CNS involvement can lead to acute neurologic symptoms or signs that need prompt evaluation and treatment. Radiotherapy (RT) can lead to quick disease response, but how it can best be incorporated early into multi-modality treatment in the urgent clinical setting is often unclear.

Methods

Here, we outline a practical approach to planning and incorporating urgent RT in patients with hematologic malignancies involving the CNS. We provide a review of the literature to inform RT indications, timing, dosing, and treatment volumes by histology and clinical scenario. We also highlight evolving controversies in this field and growing indications for RT in conjunction with novel therapeutics.

Results

RT is often the quickest-acting, most reliable tool to salvage cranial neuropathies or neurologic deficits and should be considered early. If systemic or intrathecal therapy are expected to achieve swift response as upfront treatment, simulation should still be planned in the event that response is delayed and RT is needed. RT in combination with certain systemic or intrathecal therapies can lead to unacceptable neurotoxicity; therefore, early multidisciplinary discussion to appropriately sequence therapies is critical. Thorough work-up with systemic imaging, complete neuroaxis MRI, ophthalmologic exam, and cerebrospinal fluid sampling can dictate target volumes from focal RT to comprehensive craniospinal irradiation (CSI). Dosing can range from as low as 4 Gray (Gy) for indolent disease to 36-50 Gy for more aggressive or refractory disease. Often, mid-treatment re-planning can be considered to address swift volume reduction to improve the therapeutic window. RT plays a promising role for bridging symptomatic patients to novel therapeutics (e.g., chimeric antigen receptor T-cell therapy), but optimal dosing and treatment volumes are evolving topics that require further prospective evaluation.

Conclusions

RT is a powerful tool for achieving rapid responses in hematologic malignancies and therefore should be considered early in urgent neurologic settings. Thorough workup and discussions with the multi-disciplinary team are critical to best incorporate RT in the context of other CNS-penetrating therapies. Further work is warranted on defining RT target volumes in the context of novel therapeutics.

Therapeutics of acute myeloid leukemia with central nervous system involvement

FLT3-mutated acute myeloid leukemia (AML) with central nervous system (CNS) involvement poses therapeutic challenges. We describe two cases and performed a systematic review evaluating the efficacy of therapeutic strategies in CNS involvement for both FLT3-mutated and wild-type (WT) AML. A MEDLINE, EMBASE, and Cochrane literature search identified relevant studies. Although CNS involvement in AML is associated with poor prognosis, routine CNS prophylaxis is not standard. Due to the uncertainty regarding the effect of intermediate doses of cytarabine on CNS involvement, we support a diagnostic lumbar puncture (LP) after achieving complete remission in patients with risk factors for CNS infiltration. Consolidation management should be modified depending on the result of the LP. The impact of total body irradiation (TBI) as a conditioning regimen in allogeneic stem cell transplantation on CNS AML outcomes remains ambiguous. Routine craniospinal irradiation is not recommended due to its associated higher morbidity rates, while cranial radiotherapy is preferred, particularly when combined with TBI. Fortunately, currently we can employ a FLT3 inhibitor with CNS penetrance in FLT3-mutated (either gilteritinib or sorafenib) or FLT3-WT (sorafenib) AML patients.

Clinical and biological advances of critical complications in acute myeloid leukemia

Managing acute myeloid leukemia (AML) and its critical complications requires understanding the complex interplay between disease biology, treatment strategies, and patient characteristics. Complications like sepsis, acute respiratory failure (ARF), hyperleukocytosis, coagulopathy, tumor lysis syndrome (TLS) and central nervous system (CNS) involvement present unique challenges needing precise evaluation and tailored interventions. Venetoclax-induced TLS and differentiation syndrome (DS) from IDH1/IDH2 or menin inhibitors highlight the need for ongoing research and innovative approaches. As the microbiological landscape evolves and new therapeutic agents emerge, adapting strategies to mitigate harmful pharmacological interactions is crucial. Advances in understanding the genetic profiles of patients with hyperleukocytosis contribute to better-targeted therapeutic strategies. Effective AML management relies on collaborative efforts from hematologists, specialized services, and intensive care units (ICUs). This review analyzes recent data on critical AML complications, identifies areas for further investigation, and proposes ways to advance clinical research and enhance patient care strategies.

The contemporary spectrum of radiotherapy for hematologic malignancies involving the central nervous system: From focal therapy to craniospinal

The contemporary landscape of systemic therapy options for hematologic malignancies involving the central nervous system (CNS-HM) is rapidly evolving; a key question is how radiotherapy (RT) can be optimally integrated to improve patient outcomes. Historically, use of RT to treat CNS-HM was defined by broad fields and high doses. While effective, this approach raised concerns of potential neurotoxicity which significantly decreased RT utilization. RT was replaced by high-dose, CNS-penetrant, systemic therapies that offered durable control with lower perceived neurotoxic risk. But, as the therapeutic toolbox for CNS-HM expands, so too does the complexity and diversity of potential clinical scenarios where RT should be considered. In this review, we describe both well-established and emerging opportunities for RT integration, emphasizing how dose selection and field design could balance neurotoxicity risk and disease control. We propose an anatomical framework that captures the diverse utilization of RT for CNS-HM and serves as a practical guide for RT volume and dose design.

Modern Treatment Delivery of Radiotherapy for Lymphomas and Leukemias: Making Every Gy Count

Radiotherapy has a long history in the treatment of lymphoma and leukemia, in which late toxicity outcomes have motivated current goals to improve how radiotherapy is delivered. Contemporary advanced radiotherapy techniques, including intensity modulated radiation therapy (IMRT), proton therapy, deep inspiration breath hold (DIBH), aim to reduce the risk of cardiac morbidity and second cancers caused by radiotherapy while maintaining local control. We use treatment of mediastinal and gastric lymphomas to introduce how modern techniques are chosen for optimal dose delivery, followed by an anatomic site-specific discussion of testicular, bone, and central nervous system disease.

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.

Central Nervous System Involvement in Adults with Acute Leukemia: Diagnosis, Prevention, and Management

PURPOSE OF REVIEW

Recent treatment advances in both acute myeloid leukemia and acute lymphoblastic leukemia have drastically improved outcomes for these diseases, but central nervous system (CNS) relapses still occur. Treatment of CNS disease can be challenging due to the impermeability of the blood-brain barrier to many systemic therapies.

RECENT FINDINGS

The diagnosis of CNS leukemia relies on assessment of clinical symptoms, cerebrospinal fluid sampling for conventional cytology and/or flow cytometry, and neuroimaging. While treatment of CNS leukemia with systemic or intrathecal chemotherapy and/or radiation can be curative in some patients, these modalities can also lead to serious toxicities. In the modern era, prophylaxis with intrathecal chemotherapy is the most important strategy to prevent CNS relapses in high risk patients. Accurate risk stratification tools and the use of risk-adapted prophylactic therapy are imperative to improving the outcomes of patients with acute leukemias and preventing the development of CNS leukemia.

Central Nervous System Prophylaxis and Treatment in Acute Leukemias

OPINION STATEMENT

Improvements in systemic therapy in the treatment of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) have improved patient outcomes and reduced the incidence of CNS relapse. However, management of patients with CNS disease remains challenging, and relapses in the CNS can be difficult to salvage. In addition to treatment with CNS-penetrant systemic therapy (high-dose methotrexate and cytarabine), intrathecal prophylaxis is indicated in all patients with ALL, however is not uniformly administered in patients with AML without high-risk features. There is a limited role for radiation treatment in CNS prophylaxis; however, radiation should be considered for consolidative treatment in patients with CNS disease, or as an option for palliation of symptoms. Re-examining the role of established treatment paradigms and investigating the role of radiation as bridging therapy in the era of cellular therapy, particularly in chemotherapy refractory patients, is warranted.

Neurologic complications of acute myeloid leukemia. Diagnostic approach and therapeutic modalities

Acute myeloid leukemia (AML) comprises a heterogeneous group of aggressive blood malignancies that arise from clonal expansion of malignant hematopoietic precursor cells in the bone marrow. Neurologic manifestations of these malignancies are manifolds. AML is the most common form of acute leukemia in adults and this review describes the neurologic complications in this age group. Neurologic symptoms and signs may develop in AML either from a direct neoplastic involvement of the central or the peripheral nervous system or as an indirect effect of the disease process. Direct involvement of the nervous system includes invasion of the central or the peripheral nervous system (parenchymal and leptomeningeal dissemination, myeloid sarcoma, neuroleukemiosis). Thrombotic and hemorrhagic events are common manifestations of indirect involvement of the nervous system and they are the outcome of hyperleukocytosis, thrombocytopenia and coagulopathy. Many neurologic complications are iatrogenic and include diverse categories such as lumbar puncture and intrathecal or systemic chemotherapy and targeted therapies, radiotherapy and allogeneic stem cell transplantation. Most neurologic manifestations require urgent treatment and confer a poor prognosis. This review describes the neurologic complications of acute myeloid malignancies in the era of contemporary treatment. Those manifestations require expert consideration of their origin as they are being identified with increasing frequency as patients survive longer.

Malignant Meningitis Associated with Hydrocephalus

Malignant meningitis (MM) is the diffuse involvement of the leptomeninges by infiltrating cancer cells, most frequently from lung and breast cancers. This review is aimed to discuss the current advances in the diagnosis and management of MM, along with management of MM-associated hydrocephalus. We reviewed the literature using PubMed and Google Scholar search engines, focusing on various recent randomized controlled trials and clinical trials on MM. Given the hallmark multifocal involvement, the clinical symptoms and signs are also random and asymmetric. There are three important pillars for establishing a diagnosis of MM: clinical examination, neuroimaging, and CSF cytological findings. Several factors should be considered in decision-making, including performance status, neurological findings (clinical, MRI, and CSF flow dynamic), and evaluation of the primary tumor (nature and systemic dissemination). Response Assessment in Neuro-Oncology (RANO) working group recommended the objective assessment of disease for evaluating the progression and response to therapy. Pillars of current management are mainly focal irradiation and intrathecal or systemic chemotherapy. Symptomatic hydrocephalus is managed with a ventriculoperitoneal shunt, lumboperitoneal shunt, or endoscopic third ventriculostomy as palliative procedures, providing significant improvement in performance scores in the limited survival time of patients with MM. Studies using novel therapeutic approaches, such as new biological or cytotoxic compounds, are ongoing. Despite the use of all the combinations, the overall prognosis remains grim; therefore, decision-making for treatment should predominantly be based on attaining an optimal quality of life.

Prognostic factors for clinical outcomes of patients with central nervous system leukemia

Prognostic factors associated with clinical outcomes of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) patients with central nervous system (CNS) involvement are unknown. We retrospectively studied the characteristics and outcomes of 66 (18 pediatric and 48 adult) patients with CNS leukemia with ALL (n = 41) or AML (n = 25). The median age of patients at diagnosis of CNS leukemia was 30 (range, 1-69) years. Nearly two-third patients had CNS involvement at the initial diagnosis of leukemia. Complete remission of CNS leukemia was attained in 58 (88%) patients, and probability of overall survival at 36 months after the diagnosis of CNS leukemia was 43% for the entire cohort. We identified that achieving remission of systemic leukemia and having CNS leukemia diagnosed and treated before allogeneic transplantation were the factors associated with CNS leukemia remission. Prognostic factors associated with better overall survival in patients with CNS leukemia included pediatric age, diagnosis of CNS leukemia before receiving allogenic transplantation, achieving clearance of systemic or CNS leukemia, receiving no cranial radiation in conjunction with intrathecal chemotherapy (IT), and receiving IT consolidation after achieving remission of CNS leukemia. Our findings show that patients with CNS leukemia are at considerable risk of mortality. Awareness of modifiable prognostic factors such as avoidance of cranial radiation whenever possible and use of IT consolidation can result in improved outcomes in subset of patients with CNS leukemia.

Leptomeningeal Carcinomatosis: Molecular Landscape, Current Management, and Emerging Therapies

Leptomeningeal carcinomatosis is a devastating consequence of late-stage cancer, and despite multimodal treatment, remains rapidly fatal. Definitive diagnosis requires identification of malignant cells in the cerebrospinal fluid (CSF), or frank disease on MRI. Therapy is generally palliative and consists primarily of radiotherapy and/or chemotherapy, which is administered intrathecally or systemically. Immunotherapies and novel experimental therapies have emerged as promising options for decreasing patient morbidity and mortality. In this review, the authors discuss a refined view of the molecular pathophysiology of leptomeningeal carcinomatosis, current approaches to disease management, and emerging therapies.

Emergent Radiotherapy for Leukemia-Induced Cranial Neuropathies Refractory to Intrathecal Therapy

Neurologic symptoms from leukemic infiltration of the central nervous system are an oncologic emergency, and expeditious treatment is required to preserve function. We report the case of a 44-year-old patient with relapsed acute myeloid leukemia (AML) who developed sub-acute cranial neuropathies refractory to treatment with intrathecal (IT) chemotherapy. The patient was therefore treated with an emergent course of whole-brain radiotherapy, resulting in immediate improvement and subsequent resolution of cranial neuropathies. This case illustrates that while central nervous system involvement by AML is rare, radiotherapy remains an effective modality to avoid long-term morbidity in patients failing to respond to systemic or IT chemotherapy.

A systematic review of craniospinal irradiation for leptomeningeal disease: past, present, and future

PURPOSE

Leptomeningeal disease (LMD) is a rare but deadly complication of cancer in which the disease spreads to the cerebrospinal fluid and seeds the meninges of the central nervous system (CNS). Craniospinal irradiation (CSI) involves treatment of the entire CNS subarachnoid space and is occasionally used as a last-resort palliative therapy for LMD.

METHODS

This review examined literature describing the role of CSI for LMD from solid and hematologic malignancies in adults. A search for studies published until September 1, 2020 was conducted using PubMed database.

RESULTS

A total of 262 unique articles were identified. Thirteen studies were included for analysis in which a total of 275 patients were treated with CSI for LMD. Median age at time of irradiation was 43 years, and most patients had KPS score of 70 and higher. The most common cancers resulting in LMD were acute lymphocytic leukemia, breast cancer, and acute myelogenous leukemia. Median CSI dose was 30 Gy and 18% of patients were treated with proton radiation. 52% of patients had stable-to-improved neurologic symptoms. Median overall survival for the entire cohort was 5.3 months. Patients treated with marrow-sparing proton radiation had median OS of 8 months. The most common treatment toxicities were hematologic and gastrointestinal events.

CONCLUSIONS

Despite advances in systemic and radiation therapies, LMD remains a devastating end-stage complication of some malignancies. Treatment-related toxicities can be a significant barrier to CSI delivery. In select patients with LMD, marrow-sparing proton CSI may provide safer palliation of symptoms and prolong survival.

[Treatment of central nervous system leukemia with CD19-chimeric antigen receptor T-cell immunotherapy: two cases report and literature review]

Objective: To explore the efficacy and safety of chimeric antigen receptor T (CAR-T) cells in the treatment of central nervous system leukemia (CNSL). Methods: Two leukemia patients with CNSL were treated with CD19-CAR-T cells. The process and results of the entire treatment is reported and related literature review is conducted. Results: The patients were diagnosed as acute myeloid leukemia (AML)-M(2) with B lymphoid antigen expression and B cell acute lymphoblastic leukemia(B-ALL) by morphology and immunophenotype assay. The immunophenotype was consistent with the abnormal manifestations of AML-M(2) and B-ALL. Their clinical manifestations and laboratory tests met the diagnostic criteria of CNSL. The diagnosis was clear and the two patients were treated with CD19-CAR-T cell immunotherapy. Central nervous system symptoms were relieved. The imaging abnormalities of patient one has disappeared but cytokines release syndrome (CRS) occurred during the treatment. Cerebrospinal fluid of patient two was negative and no obvious CRS reaction was found. Conclusions: CAR-T cell immunotherapy is likely to induce the remission of CNSL and improve the prognosis.

Radiation therapy and PD-1/PD-L1 blockade: the clinical development of an evolving anticancer combination

Several inhibitors of programmed cell death-1 (PD-1) and programmed death ligand-1 (PD-L1) have been approved as a form of immunotherapy for multiple cancers. Ionizing radiation therapy (RT) has been shown to enhance the priming and effector phases of the antitumor T-cell response rendering it an attractive therapy to combine with PD-1/PD-L1 inhibitors. Preclinical data support the rational combination of the 2 modalities and has paved way for the clinical development of the combination across a spectrum of cancers. In this review, we highlight the preclinical and clinical development of combined RT and PD-1/PD-L1 blockade to date. In addition to a comprehensive evaluation of available safety and efficacy data, we discuss important points of consideration in clinical trial design for this promising combination.

Leptomeningeal metastasis from systemic cancer: Review and update on management

Leptomeningeal metastasis is an uncommon and typically late complication of cancer with a poor prognosis and limited treatment options. Diagnosis is often challenging, with nonspecific presenting symptoms ranging from headache and confusion to focal neurologic deficits, such as cranial nerve palsies. Standard diagnostic evaluation involves a neurologic examination, magnetic resonance imaging of the brain and spine with gadolinium, and cytologic evaluation of the cerebral spinal fluid. Therapy entails a multimodal approach focused on palliation with surgery, radiation, and/or chemotherapy, which may be administered systemically or directly into the cerebral spinal fluid. Limited trial data exist to guide treatment, and current regimens are based primarily on expert opinion. Although newer targeted and immunotherapeutic agents are under investigation and have shown promise, an improved understanding of the biology of leptomeningeal metastasis and treatment resistance as well as additional randomized controlled studies are needed to guide the optimal treatment of this devastating disease. Cancer 2018;124:21-35. © 2017 American Cancer Society.

Craniospinal irradiation prior to stem cell transplant for hematologic malignancies with CNS involvement: Effectiveness and toxicity after photon or proton treatment

PURPOSE/OBJECTIVE(S)

Craniospinal irradiation (CSI) improves local control of leukemia/lymphoma with central nervous system (CNS) involvement; however, for adult patients anticipating stem cell transplant (SCT), cumulative treatment toxicity is a major concern. We evaluated toxicities and outcomes for patients receiving proton or photon CSI before SCT.

METHODS AND MATERIALS

We identified 37 consecutive leukemia/lymphoma patients with CNS involvement who received CSI before SCT at our institution. Photon versus proton toxicities during CSI, transplant, and through 100 days posttransplant were compared using Fisher exact and Wilcoxon rank sum tests. Long-term neurotoxicity, disease response, and overall survival were analyzed.

RESULTS

Thirty-seven patients (23 photon, 14 proton) underwent CSI for CNS involvement of acute lymphoblastic leukemia (49%), acute myeloblastic leukemia (22%), chronic lymphocytic leukemia (3%), chronic myelocytic leukemia (14%), lymphoma (11%), and myeloma (3%). CSI was used for consolidation (30 patients, 81%) and gross disease treatment (7 patients, 19%). Median radiation dose (interquartile range) was 24 Gy (23.4-24) for photons and 21.8 Gy (21.3-23.6) for protons (P = .03). Proton CSI was associated with lower rates of Radiation Therapy Oncology Group grade 1-3 mucositis during CSI (7% vs 44%, P = .03): 1 grade 3 with protons versus 5 grade 1, 3 grade 2, and 2 grade 3 with photons. During CSI, other toxicities (infection, gastrointestinal symptoms) did not differ. Allogeneic stem cell transplant (SCT) was used in 95% of patients, with 53% of patients in remission before SCT. Myeloablative conditioning was used for 76%. During SCT admission and 100 days post-SCT, toxicities did not differ by CSI technique. Successful engraftment occurred in 95% of patients (P = .67). Progression or death occurred for 47% of patients, with only 1 CNS relapse.

CONCLUSION

In our cohort, CSI offered excellent local control for CNS-involved hematologic malignancies in the pre-SCT setting. Acute mucositis occurred less frequently with proton CSI with comparable peritransplant/long-term toxicity profile, suggesting the need to further explore the benefit/toxicity profile of this technique.

Neurological Complications of the Leukemias Across the Ages

PURPOSE OF REVIEW

Acute and chronic leukemias are heterogeneous diseases and can affect any part of the body upon initial discovery. Understanding the sequela of systemic involvement is key for proper diagnosis and treatment.

RECENT FINDINGS

Over the decades, new research has emerged regarding neurological complications of the myeloid or lymphoid leukemias. Central nervous system involvement usually confers a poor prognosis and requires emergent treatment. Standard of care still involves systemic therapy, intrathecal administration of chemotherapeutic agents, and cranial radiation. Treatment-related side effects can occur and need to be recognized by any practitioner involved with patient care. It is imperative to understand neurologic complications from leukemia to prevent delays and initiate necessary treatment to maintain neurologic and cognitive function.