Updates in the Management of Metastatic Spine Disease.

The number of cancer diagnoses continues to increase each year in the United States, and given the propensity for bone metastases from solid organ malignancies, orthopaedic spine surgeons will inevitably encounter patients with metastatic spine disease and need to have a framework for approaching the evaluation and treatment of these complex patients. Many patients seeking care for spinal metastases already have a history of disseminated malignancy, but metastatic spine disease itself will be the presenting symptom of cancer in approximately 20% of patients. Because the first presentation of cancer may be to a spine surgeon, an appropriate strategy for the initial evaluation of a patient with a new spinal lesion is critical to establish the diagnosis of metastatic disease before undergoing treatment. Once the diagnosis of metastatic spine disease is confirmed, decisions regarding treatment should be made in coordination with a multidisciplinary team including radiation oncology and medical oncology. Spinal metastases are most often treated with radiation therapy. Direct circumferential decompression of the spinal cord with postoperative radiation therapy is considered for high-grade epidural spinal cord compression to preserve neurologic function. Mechanical spinal instability is another potential indication for surgery. When considering surgery, the patient's medical fitness, systemic burden of cancer, and overall prognosis all must be accounted for, and the importance of multidisciplinary evaluation and shared decision making cannot be overstated.

Estrategias de tratamiento en la metástasis vertebral. Necesidad de comités multidisciplinarios desde la perspectiva del cirujano. Narración de la literatura / Treatment strategies in vertebral metastasis. Need for multidisciplinary committees from the perspective of the surgeon. Narration of literatura

Las mejoras en el diagnóstico y tratamiento del cáncer han mejorado la supervivencia. Secundariamente también aumenta el número de estos pacientes que presentan una metástasis vertebral y el número con alguna morbilidad en relación con estas metástasis. Fractura vertebral, compresión radicular o lesión medular causan un deterioro de su calidad de vida. El objetivo en el tratamiento de las mismas ha de ser el control del dolor, mantenimiento función neurológica y de la estabilidad vertebral, teniendo presente que en muchos casos será un tratamiento paliativo.El tratamiento de estas complicaciones presenta un enfoque multidisciplinario, radiólogos, radiólogos intervencionistas, oncólogos y radioterapeutas, cirujanos de raquis, pero también Unidad de Rehabilitación o Unidad de Dolor. Recientes trabajos muestran que un enfoque multidisciplinario de estos pacientes puede mejorar calidad de vida e incluso pronóstico.En el presente trabajo se realiza una revisión y lectura de la bibliografía sobre el manejo multidisciplinario de estos pacientes.(AU)

Improvements in cancer diagnosis and treatment have improved survival. Secondarily, the number of patients who present a vertebral metastasis and the number with some morbidity in relation to these metastases also increases. Vertebral fracture, root compression or spinal cord injury cause a deterioration of their quality of life.The objective in the treatment of the vertebral metastasis must be the control of pain, maintenance of neurological function and vertebral stability, bearing in mind that in most cases it will be a palliative treatment.The treatment of these complications needs a multidisciplinary approach, radiologists, interventional radiologists, oncologists and radiation therapists, spine surgeons, but also rehabilitation or pain units. Recent studies show that a multidisciplinary approach of these patients can improve quality of life and even prognosis.In the present article, a review and reading of the literature on the multidisciplinary management of these patients is carried out.(AU)

[Translated article] Treatment strategies in vertebral metastasis. Need for multidisciplinary committees from the perspective of the surgeon. Narration of literature / Estrategias de tratamiento en la metástasis vertebral. Necesidad de comités multidisciplinarios desde la perspectiva del cirujano. Narración de la literatura

Las mejoras en el diagnóstico y tratamiento del cáncer han mejorado la supervivencia. Secundariamente también aumenta el número de estos pacientes que presentan una metástasis vertebral y el número con alguna morbilidad en relación con estas metástasis. Fractura vertebral, compresión radicular o lesión medular causan un deterioro de su calidad de vida. El objetivo en el tratamiento de las mismas ha de ser el control del dolor, mantenimiento función neurológica y de la estabilidad vertebral, teniendo presente que en muchos casos será un tratamiento paliativo.El tratamiento de estas complicaciones presenta un enfoque multidisciplinario, radiólogos, radiólogos intervencionistas, oncólogos y radioterapeutas, cirujanos de raquis, pero también Unidad de Rehabilitación o Unidad de Dolor. Recientes trabajos muestran que un enfoque multidisciplinario de estos pacientes puede mejorar calidad de vida e incluso pronóstico.En el presente trabajo se realiza una revisión y lectura de la bibliografía sobre el manejo multidisciplinario de estos pacientes.(AU)

Improvements in cancer diagnosis and treatment have improved survival. Secondarily, the number of patients who present a vertebral metastasis and the number with some morbidity in relation to these metastases also increases. Vertebral fracture, root compression or spinal cord injury cause a deterioration of their quality of life.The objective in the treatment of the vertebral metastasis must be the control of pain, maintenance of neurological function and vertebral stability, bearing in mind that in most cases it will be a palliative treatment.The treatment of these complications needs a multidisciplinary approach, radiologists, interventional radiologists, oncologists and radiation therapists, spine surgeons, but also rehabilitation or pain units. Recent studies show that a multidisciplinary approach of these patients can improve quality of life and even prognosis.In the present article, a review and reading of the literature on the multidisciplinary management of these patients is carried out.(AU)

[Artículo traducido] Manejo de metástasis sintomáticas de columna: un enfoque multidisciplinario basado en un diagrama de flujo / Management of symptomatic spine metastases: A multidisciplinary approach based flow-chart

Describimos un algoritmo para el manejo de las metástasis espinales en el que la importancia de los parámetros individuales varía dependiendo del momento en el que se contemplan.Cada paciente sigue su propio proceso secuencial «personal» que no necesariamente considera todos los parámetros cada vez, ya que algunos pueden ser irrelevantes a la hora de elegir el tipo de tratamiento para ese individuo. Por ejemplo, un paciente en mal estado general con una puntuación ASA alta generalmente no es candidato para la cirugía, independientemente de la naturaleza del tumor primario o del número de metástasis. Para este paciente, el elemento más importante sería la sensibilidad del tumor al tratamiento adyuvante. Del mismo modo, un paciente con lesión aguda y progresiva de la médula espinal se sometería a descompresión quirúrgica y estabilización sin considerar una intervención más agresiva.(AU)

We described an algorithm for the management of spinal metastases in which the importance of single parameters varies depending on when they are contemplated.Each patient follows his own «personal» sequential process which does not necessarily consider all the parameters each time as some may be irrelevant for the purpose of choosing the type of treatment for that single individual. For instance, a patient in general poor condition with a high ASA score is usually not a candidate for surgery, regardless of the primary tumor nature or the number of metastases. For this patient, the most important element would be the sensitivity of the tumor to adjuvant treatment. Similarly, a patient with acute and progressive spinal cord injury would undergo surgical decompression and stabilization without considering a more strenuous intervention.(AU)

Management of symptomatic spine metastases: A multidisciplinary approach based flow-chart / Manejo de metástasis sintomáticas de columna: un enfoque multidisciplinario basado en un diagrama de flujo

Describimos un algoritmo para el manejo de las metástasis espinales en el que la importancia de los parámetros individuales varía dependiendo del momento en el que se contemplan.Cada paciente sigue su propio proceso secuencial «personal» que no necesariamente considera todos los parámetros cada vez, ya que algunos pueden ser irrelevantes a la hora de elegir el tipo de tratamiento para ese individuo. Por ejemplo, un paciente en mal estado general con una puntuación ASA alta generalmente no es candidato para la cirugía, independientemente de la naturaleza del tumor primario o del número de metástasis. Para este paciente, el elemento más importante sería la sensibilidad del tumor al tratamiento adyuvante. Del mismo modo, un paciente con lesión aguda y progresiva de la médula espinal se sometería a descompresión quirúrgica y estabilización sin considerar una intervención más agresiva.(AU)

We described an algorithm for the management of spinal metastases in which the importance of single parameters varies depending on when they are contemplated.Each patient follows his own «personal» sequential process which does not necessarily consider all the parameters each time as some may be irrelevant for the purpose of choosing the type of treatment for that single individual. For instance, a patient in general poor condition with a high ASA score is usually not a candidate for surgery, regardless of the primary tumor nature or the number of metastases. For this patient, the most important element would be the sensitivity of the tumor to adjuvant treatment. Similarly, a patient with acute and progressive spinal cord injury would undergo surgical decompression and stabilization without considering a more strenuous intervention.(AU)

Papel de la radioterapia en el manejo de las metástasis vertebrales: últimas novedades / Role of radiotherapy in the management of spine metastases

Las metástasis vertebrales son una causa común de dolor en el paciente oncológico, lo cual puede generar limitación funcional, además de complicaciones derivadas de una posible compresión medular, radicular y fracturas. Se requiere de un abordaje complejo de estas metástasis por el riesgo de secuelas permanentes. Con el aumento de las supervivencia gracias a los nuevos tratamientos emergentes, las posibilidades de presentar metástasis vertebrales son cada vez mayores, por ende, el manejo de estas lesiones debe ir encaminado al alivio del dolor y el mantenimiento de la deambulación. La radioterapia juega un papel fundamental en el manejo de estas lesiones, y disponemos de avances tecnológicos en los últimos años que han permitido mejorar la calidad e intencionalidad de los tratamientos, pasando de ser meramente paliativos a proponer tratamientos que mejoren el control local. En este articulo hacemos una descripción de como la técnica de SBRT (stereotactic body radiotherapy), en pacientes seleccionados puede mejorar el control local de forma más duradera, y el valor que tiene en paciente oligometastásico y tras cirugía.(AU)

Spine metastases are a common cause of pain in the oncologic patient which can generate functional limitation, in addition to complications derived from spinal cord compression, radicular compression and fractures. A complex approach to these metastases is required due to the risk of permanent sequelae. With the increase in survival rates due to new emerging treatments, the possibilities of presenting vertebral metastases are increasing, therefore, the management of these lesions should be aimed at pain relief and maintenance of ambulation. Radiotherapy has a fundamental role in the management of these lesions, and technological advances in recent years have made it possible to improve the quality and intentionality of the treatments, going from having a palliative intent to proposing treatments that improve local control. In this article we describe how the stereotactic body radiotherapy (SBRT) technique, in selected patients, can improve local control and its value in oligometastatic patients and after surgery.(AU)

[Translated article] Role of radiotherapy in the management of spine metastases / Papel de la radioterapia en el manejo de las metástasis vertebrales: últimas novedades

Las metástasis vertebrales son una causa común de dolor en el paciente oncológico, lo cual puede generar limitación funcional, además de complicaciones derivadas de una posible compresión medular, radicular y fracturas. Se requiere de un abordaje complejo de estas metástasis por el riesgo de secuelas permanentes. Con el aumento de las supervivencia gracias a los nuevos tratamientos emergentes, las posibilidades de presentar metástasis vertebrales son cada vez mayores, por ende, el manejo de estas lesiones debe ir encaminado al alivio del dolor y el mantenimiento de la deambulación. La radioterapia juega un papel fundamental en el manejo de estas lesiones, y disponemos de avances tecnológicos en los últimos años que han permitido mejorar la calidad e intencionalidad de los tratamientos, pasando de ser meramente paliativos a proponer tratamientos que mejoren el control local. En este articulo hacemos una descripción de como la técnica de SBRT (stereotactic body radiotherapy), en pacientes seleccionados puede mejorar el control local de forma más duradera, y el valor que tiene en paciente oligometastásico y tras cirugía.(AU)

Spine metastases are a common cause of pain in the oncologic patient which can generate functional limitation, in addition to complications derived from spinal cord compression, radicular compression and fractures. A complex approach to these metastases is required due to the risk of permanent sequelae. With the increase in survival rates due to new emerging treatments, the possibilities of presenting vertebral metastases are increasing, therefore, the management of these lesions should be aimed at pain relief and maintenance of ambulation. Radiotherapy has a fundamental role in the management of these lesions, and technological advances in recent years have made it possible to improve the quality and intentionality of the treatments, going from having a palliative intent to proposing treatments that improve local control. In this article we describe how the stereotactic body radiotherapy (SBRT) technique, in selected patients, can improve local control and its value in oligometastatic patients and after surgery.(AU)

Metástasis vertebrales. Tratamiento en bloque / Vertebral metastases. En bloc treatment

La resección en bloque de metástasis en columna vertebral ha sido objeto de estudio en la literatura médica debido a su impacto en la calidad de vida de los pacientes y su efectividad en el control local de la enfermedad. Este análisis bibliográfico examina los hallazgos y perspectivas de estudios publicados en relación con la resección en bloque de oligometástasis vertebrales. La técnica, que implica la extirpación completa del tumor junto con una porción del hueso circundante, ha demostrado mejorar el control local del tumor, reducir la recurrencia y potencialmente prolongar la supervivencia de los pacientes en comparación con las técnicas convencionales de descompresión y estabilización. Sin embargo, la resección en bloque también presenta riesgos y complicaciones, como la morbilidad quirúrgica y el mayor tiempo de recuperación. La selección adecuada de pacientes, la planificación preoperatoria y el enfoque multidisciplinario son fundamentales para optimizar los resultados. A medida que se desarrollan nuevas técnicas y avances en el tratamiento adyuvante, la resección en bloque de oligometástasis vertebrales sigue siendo un área de interés en la investigación oncológica.(AU)

En bloc resection of vertebral metastases has been the subject of study in medical literature due to its impact on patients’ quality of life and effectiveness in local disease control. This bibliographic analysis examines the findings and perspectives of published studies concerning en bloc resection of oligometastases in the spine. The technique, which involves the complete removal of the tumour along with a portion of the surrounding bone, has been shown to improve local tumour control, reduce recurrence, and potentially prolong patient survival compared to conventional decompression and stabilization techniques. However, en bloc resection also presents risks and complications, such as surgical morbidity and extended recovery time. Appropriate patient selection, preoperative planning, and a multidisciplinary approach are essential to optimize outcomes. As new techniques and advances in adjuvant treatment develop, en bloc resection of oligometastases in the spine remains an area of interest in oncological research.(AU)

[Translated article] Vertebral metastases. En bloc treatment / Metástasis vertebrales. Tratamiento en bloque

La resección en bloque de metástasis en columna vertebral ha sido objeto de estudio en la literatura médica debido a su impacto en la calidad de vida de los pacientes y su efectividad en el control local de la enfermedad. Este análisis bibliográfico examina los hallazgos y perspectivas de estudios publicados en relación con la resección en bloque de oligometástasis vertebrales. La técnica, que implica la extirpación completa del tumor junto con una porción del hueso circundante, ha demostrado mejorar el control local del tumor, reducir la recurrencia y potencialmente prolongar la supervivencia de los pacientes en comparación con las técnicas convencionales de descompresión y estabilización. Sin embargo, la resección en bloque también presenta riesgos y complicaciones, como la morbilidad quirúrgica y el mayor tiempo de recuperación. La selección adecuada de pacientes, la planificación preoperatoria y el enfoque multidisciplinario son fundamentales para optimizar los resultados. A medida que se desarrollan nuevas técnicas y avances en el tratamiento adyuvante, la resección en bloque de oligometástasis vertebrales sigue siendo un área de interés en la investigación oncológica.(AU)

En bloc resection of vertebral metastases has been the subject of study in medical literature due to its impact on patients’ quality of life and effectiveness in local disease control. This bibliographic analysis examines the findings and perspectives of published studies concerning en bloc resection of oligometastases in the spine. The technique, which involves the complete removal of the tumour along with a portion of the surrounding bone, has been shown to improve local tumour control, reduce recurrence, and potentially prolong patient survival compared to conventional decompression and stabilization techniques. However, en bloc resection also presents risks and complications, such as surgical morbidity and extended recovery time. Appropriate patient selection, preoperative planning, and a multidisciplinary approach are essential to optimize outcomes. As new techniques and advances in adjuvant treatment develop, en bloc resection of oligometastases in the spine remains an area of interest in oncological research.(AU)

[Pediatric spinal tumors]. / Spinale Tumoren im Kindesalter.

Pediatric spinal tumors are rare and manifest frequently with unspecific symptoms, frequently resulting in delayed diagnosis. Many spinal tumor entities in children and adults are similar, but the lesions demonstrate a different prevalence and sometimes a different molecular genetic profile in children. For radiological evaluation of spinal tumor lesions, it is helpful to define the affected anatomical compartment. Important intradural pediatric tumor entities are astrocytomas, ependymomas, nerve sheath tumors, and liquorgenic metastases of intracranial neoplasms. Extradural masses are mostly primary tumors originating from osseous elements of the spine. Bone metastases are rare in children and can occur, for example, in neuroblastoma. Magnetic resonance imaging (MRI) is the most important noninvasive method for radiological spinal tumor evaluation.

Metastatic Lesions of the Brain and Spine.

Brain and spinal metastases are common in cancer patients and are associated with significant morbidity and mortality. Continued advancement in the systemic care of cancer has increased the life expectancy of patients, and consequently, the incidence of brain and spine metastasis has increased. There has been an increase in the understanding of oncogenic mutations, and research has also demonstrated spatial and temporal mutations in patients that may drive overall treatment resistance and failure. Combinatory treatments with radiation, surgery, and newer systemic therapies have continued to increase the life expectancy of patients with brain and spine metastases. Given the overall complexity of brain and spine metastases, this chapter aims to give a comprehensive overview and cover important topics concerning brain and spine metastases. This will include the molecular, genetic, radiographic, surgical, and non-surgical treatments of brain and spinal metastases.

Malignant Spinal Tumors.

Malignant spinal tumors constitute around 22% of all primary spinal tumors. The most common location of metastases to the spinal region is the extradural compartment. The molecular and genetic characterization of these tumors was the basis for the updated WHO classification of CNS tumors in 2016, where many CNS tumors are now diagnosed according to their genetic profile rather than relying solely on the histopathological appearance. Magnetic resonance imaging (MRI) is the current gold standard for the initial evaluation and subsequent follow-up on intradural spinal cord tumors, and the imaging sequences must include T2-weighted images (WI), short time inversion recovery (STIR), and pre- and post-contrast T1-WI in the axial, sagittal, and coronal planes. The clinical presentation is highly variable and depends on the tumor size, growth rate, type, infiltrative, necrotic and hemorrhagic potential as well as the exact location within the spinal compartment. Surgical intervention remains the mainstay of management of symptomatic and radiographically enlarging spinal tumors, where the goal is to achieve maximal safe resection. Tumor recurrences are managed with repeat surgical resection (preferred whenever possible and safe), radiotherapy, chemotherapy, or any combination of these therapies.

Malignant spinal cord compression in the paediatric population-a systematic review, meta-analysis.

BACKGROUND: Malignant spinal cord compression (MSCC) has been noted in 3-5% of children with primary tumours. MSCC can be associated with permanent neurological deficits and prompt treatment is necessary. Our aim was to perform a systematic review on MSCC in children < 18 years to help formulate national guidelines. METHODS: A systematic review of the English language was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Search criteria included 'MSCC in children, paediatric and metastases' for papers published between January1999 and December 2022. Isolated case reports/case series with < 10 patients were excluded. RESULTS: From a total of 17 articles identified, a final 7 were analysed (Level III/IV). Neuroblastoma constituted the most common cause for MSCC in children (62.7%) followed by sarcoma (14.2%). Soft tissue sarcomas were the most frequent cause of MSCC in children > 5 years old, while for neuroblastomas, the mean age of presentation was 20 months. The median age at time of diagnosis for the entire cohort of patients was 50.9 months (14.8-139). The median follow-up duration was 50.7 months (0.5-204). Motor deficits were the presenting symptom in 95.6% of children followed by pain in 65.4% and sphincter disturbance in 24%. There was a delay of about 26.05 days (7-600) between the onset of symptoms and diagnosis. A multimodality approach to treatment was utilised depending on the primary tumour. The prognosis for neurological recovery was found to be inversely proportional to the degree of neurological deficits and duration of symptoms in four studies. CONCLUSION: Neuroblastoma is the most common cause for MSCC in children (62.7%) followed by sarcoma (14.2%), whilst soft tissue sarcomas constituted the most frequent cause of MSCC in children > 5 years old. The majority of patients presented with motor deficit, followed by pain. In children with neuroblastoma /lymphoma, chemotherapy was the primary treatment. Early surgery should be a consideration with rapid deterioration of neurology despite chemotherapy. A multimodality approach including chemo-radiotherapy and surgery should be the treatment of choice in metastatic sarcomas. It is worth noting that multi-level laminectomy/decompression and asymmetrical radiation to the spine can lead to spinal column deformity in the future.

Dynamic Contrast-Enhanced MR Perfusion: Role in Diagnosis and Treatment Follow-Up in Patients with Vertebral Body Tumors.

Recent therapeutic advances have led to increased survival times for patients with metastatic disease. Key to survival is early diagnosis and subsequent treatment as well as early detection of treatment failure allowing for therapy modifications. Conventional MR imaging techniques of the spine can be at times suboptimal for identifying viable tumor, as structural changes and imaging characteristics may not differ pretreatment and posttreatment. Advanced imaging techniques such as DCE-MRI can allow earlier and more accurate noninvasive assessment of viable disease by characterizing physiologic changes and tumor microvasculature.

Management Algorithm for Osseous Metastatic Disease: What the Treatment Teams Want to Know.

Radiologists play a primary role in identifying, characterizing, and classifying spinal metastases and can play a lifesaving role in the care of these patients by triaging those with instability to urgent spine surgery consultation. For this reason, an understanding of current treatment algorithms and principles of spinal stability in patients with cancer is vital for all who interpret spine studies. In addition, advances in imaging allow radiologists to provide more accurate diagnoses and characterize pathology, thereby improving patient safety.

Spinal Metastases from Colorectal Cancer at Mass General Brigham: A Twenty-Year Case Series With Literature Review.

OBJECTIVE: We present an institutional case series of patients treated for colorectal carcinoma (CRC) spinal metastases to investigate the outcomes between no treatment, radiation, surgery, and surgery/radiation. METHODS: A retrospective cohort of patients with CRC spinal metastases presenting to affiliated institutions between 2001 and 2021 wereidentified. Information related to patient demographics, treatment modality, treatment outcomes, symptom improvement, and survival was collected by chart review. Overall survival (OS) was compared between treatments by log-rank significance testing. A literature review was conducted to identify other cases series of CRC patients with spinal metastases. RESULTS: Eighty-nine patients (mean age 58.5) with CRC spinal metastases across a mean of 3.3 levels met inclusion criteria: 14 (15.7%) received no treatment, 11 (12.4%) received surgery alone, 37 (41.6%) received radiation alone, and 27 (30.3%) received both radiation and surgery. Patients treated with combination therapy had the longest median OS of 24.7 months (range 0.6-85.9), which did not significantly differ from the median OS of 8.9 months (range 0.2-42.6) observed in patients who received no treatment (P = 0.075). Combination therapy provided objectively longer survival time in comparison to other treatment modalities but failed to reach statistical significance. The majority of patients that received treatment (n = 51/75, 68.0%) experienced some degree of symptomatic or functional improvement. CONCLUSIONS: Therapeutic intervention has the potential to improve the quality of life in patients with CRC spinal metastases. We demonstrate that surgery and radiation are useful options for these patients, despite their lack of objective improvement in OS.

Automating Structured Results Communication to Expedite Imaging-Directed Care in Spine Oncology.

Cancers frequently metastasize to the spine, where they can cause severe morbidity, including pain, vertebral collapse, and paralysis. Accurate assessment and timely communication of actionable imaging findings are critical. We developed a scoring mechanism to capture the key imaging features of examinations performed to detect and characterize spinal metastases in patients with cancer. An automated system was developed to relay those findings to the institution's spine oncology team to expedite treatment. This report describes the scoring scheme, the automated results communication platform, and initial clinical experience with the system. The scoring system and communication platform enable prompt, imaging-directed care of patients with spinal metastases.

Vertebral Primary Bone Lesions: Review of Management Options.

The assessment and treatment of vertebral primary bone lesions continue to pose a unique yet significant challenge. Indeed, there exists little in the literature in the way of compiling and overviewing the various types of vertebral lesions, which can often have complicated intervention strategies. Given the severe consequences of mismanaged vertebral bone tumors-including the extreme loss of motor function-it is clear that such an overview of spinal lesion care is needed. Thus, in the following paper, we aim to address the assessment of various vertebral primary bone lesions, outlining the relevant nonsurgical and surgical interventional methods. We describe examples of primary benign and malignant tumors, comparing and contrasting their differences. We also highlight emerging treatments and approaches for these tumors, like cryoablation and stereotactic body radiation therapy. Ultimately, we aim to emphasize the need for further guidelines in regard to correlating lesion type with proper therapy, underscoring the innate diversity of vertebral primary bone lesions in the literature.

Volumetric Intensity-Modulated Arc Stereotactic Radiosurgery Boost in Oligometastatic Patients with Spine Metastases: a Dose-escalation Study.

AIMS: To report the final results of a dose-escalation study of volumetric intensity-modulated arc stereotactic radiosurgery (VMAT-SRS) boost after three-dimensional conformal radiation therapy in patients with spine metastases. MATERIALS AND METHODS: Oligometastatic cancer patients bearing up to five synchronous metastases (visceral or bone, including vertebral ones) and candidates for surgery or radiosurgery were considered for inclusion. 25 Gy was delivered in 10 daily fractions (2 weeks) to the metastatic lesion, affected vertebrae and adjacent ones (one cranial and one caudal vertebra). Sequentially, the dose to spinal metastases was progressively increased (8 Gy, 10 Gy, 12 Gy) in the patient cohorts. Dose-limiting toxicities were defined as any treatment-related non-hematologic acute adverse effects rated as grade ≥3 or any acute haematological toxicity rated as ≥ 4 by the Radiation Therapy Oncology Group scale. RESULTS: Fifty-two lesions accounting for 40 consecutive patients (male/female: 29/11; median age: 71 years; range 40-85) were treated from April 2011 to September 2020. Most patients had a primary prostate (65.0%) or breast cancer (22.5%). Thirty-two patients received 8 Gy VMAT-SRS boost (total BED α/ß10: 45.6 Gy), 14 patients received 10 Gy (total BED α/ß10: 51.2 Gy) and six patients received 12 Gy (total BED α/ß10: 57.6 Gy). The median follow-up time was over 70 months (range 2-240 months). No acute toxicities > grade 2 and no late toxicities > grade 1 were recorded. The overall response rate based on computed tomography/positron emission tomography-computed tomography/magnetic resonance was 78.8%. The 24-month actuarial local control, distant metastases-free survival and overall survival rates were 88.5%, 27.1% and 90.3%, respectively. CONCLUSION: A 12 Gy spine metastasis SRS boost following 25 Gy to the affected and adjacent vertebrae was feasible with an excellent local control rate and toxicity profile.