Feasibility and Acute Toxicity of Hypo-Fractionated Radiotherapy on 0.35T MR-LINAC: The First Prospective Study in Spain.

This observational, descriptive, longitudinal, and prospective basket-type study (Registry #5289) prospectively evaluated the feasibility and acute toxicity of hypo-fractionated radiotherapy on the first 0.35T MR-LINAC in Spain. A total of 37 patients were included between August and December 2023, primarily with prostate tumors (59.46%), followed by pancreatic tumors (32.44%). Treatment regimens typically involved extreme hypo-fractionated radiotherapy, with precise dose delivery verified through quality assurance measures. Acute toxicity assessment at treatment completion revealed manageable cystitis, with one case persisting at the three-month follow-up. Gastrointestinal toxicity was minimal. For pancreatic tumors, daily adaptation of organ-at-risk (OAR) and gross tumor volume (GTV) was practiced, with median doses to OAR within acceptable limits. Three patients experienced gastrointestinal toxicity, mainly nausea. Overall, the study demonstrates the feasibility and safety of extreme hypo-fractionated radiotherapy on a 0.35T MR-LINAC, especially for challenging anatomical sites like prostate and pancreatic tumors. These findings support the feasibility of MR-LINAC-based radiotherapy in delivering precise treatments with minimal toxicity, highlighting its potential for optimizing cancer treatment strategies.

MR-LINAC, a New Partner in Radiation Oncology: Current Landscape.

Technological advances in radiation oncology are oriented towards improving treatment precision and tumor control. Among these advances, magnetic-resonance-image-guided radiation therapy (MRgRT) stands out, with technological advances to deliver targeted treatments adapted to a tumor's anatomy on the day while minimizing incidental exposure to organs at risk, offering an unprecedented therapeutic advantage compared to X-ray-based IGRT delivery systems. This new technology changes the traditional workflow in radiation oncology and requires an evolution in team coordination to administer more precise treatments. Once implemented, it paves the way for newer indication for radiation therapy to safely deliver higher doses than ever before, with better preservation of healthy tissues to optimize patient outcomes. In this narrative review, we assess the technical aspects of the novel linear accelerators that can deliver MRgRT and summarize the available published experience to date, focusing on oncological results and future challenges.

Coronavirus disease 2019 and lung cancer: where are we?

Oncology patients are more susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection due to hospital contact and an immunological system that can be compromised by antineoplastic therapy and supportive treatments. Certain similarities have been described in the physiopathology of coronavirus disease 2019 (COVID-19) and lung cancer (LC) that may explain the higher probability of these patients of developing a more serious disease with more frequent hospitalizations and even death, especially with the addition of smoking, cardiovascular and respiratory comorbidities, old age and corticosteroids use. Pre-existing lesions and cancer therapies change the normal architecture of the lungs, so diagnostic scales such as COVID-19 Reporting and Data System (CO-RADS) are of vital importance for a correct diagnosis and patient homogenization, with a high inter-observer correlation. Moreover, anticancer treatments have required an adaptation to reduce the number of visits to the hospital [hypofractionated radiotherapy (RT), larger intervals between chemotherapy cycles, delay in follow-up tests, among others]. In a way, this has also caused a delay in the diagnosis of new cancers. On the other hand, vaccination has had a positive impact on the mortality of these patients, who maintain a similar seroprevalence to the rest of the population, with a similar impact in mortality.

Evolution of dosimetric treatment planning for pediatric total lymphoid irradiation (TLI): a single-institution experience.

Background: Total lymphoid irradiation (TLI) is a conditioning regimen in allogeneic hematopoietic stem cell transplantation (allo-HSCT) which may reduce long-term toxicities attributed to other techniques, such as total body irradiation (TBI). At our institution, TLI treatments were first planned with the three-dimensional conformal radiation therapy (3D-CRT) technique and later with volumetric modulated arc therapy (VMAT). With the recent availability of a basic helical tomotherapy (HT), the possible dosimetric gain of the latter for TLI is studied. Materials and methods: 22 pediatric patients were planned for VMAT and HT, prescribed to 8 Gy in 4 fractions. VMAT was planned with template based on a single cost function, using the Monaco treatment planning system (TPS). HT plans were planned using Accuray Precision TPS for a basic HT without the dynamic jaws feature or VOLO-Ultra algorithm. Plan quality was analyzed based on four quality indices, mean and maximum doses to planning target volume (PTV) and organs at risk (OARs), dose gradient and integral doses. Differences were analyzed with Wilcoxon signed-rank test. Results: HT plans resulted in improved conformity (CI) and homogeneity indices (HI) (p < 0.05) but less steep dose gradient (p = 0.181). VMAT plans created larger areas with high doses within the PTV, while comparable doses to OARs, except mainly for the spinal marrow, for which a reduction of 37.7% in D2% was obtained (p < 0.05). Integral dose for non-tumor tissue was 11.3% lower with the VMAT template (p < 0.05). Conclusion: HT achieves better conformity and homogeneity even without its more advanced features. Nevertheless, the VMAT template achieves dosimetric results close to those of HT, both with similar clinical outcome.

ESTRO ACROP and SIOPE recommendations for myeloablative Total Body Irradiation in children.

BACKGROUND AND PURPOSE: Myeloablative Total Body Irradiation (TBI) is an important modality in conditioning for allogeneic hematopoietic stem cell transplantation (HSCT), especially in children with high-risk acute lymphoblastic leukemia (ALL). TBI practices are heterogeneous and institution-specific. Since TBI is associated with multiple late adverse effects, recommendations may help to standardize practices and improve the outcome versus toxicity ratio for children. MATERIAL AND METHODS: The European Society for Paediatric Oncology (SIOPE) Radiotherapy TBI Working Group together with ESTRO experts conducted a literature search and evaluation regarding myeloablative TBI techniques and toxicities in children. Findings were discussed in bimonthly virtual meetings and consensus recommendations were established. RESULTS: Myeloablative TBI in HSCT conditioning is mostly performed for high-risk ALL patients or patients with recurring hematologic malignancies. TBI is discouraged in children <3-4 years old because of increased toxicity risk. Publications regarding TBI are mostly retrospective studies with level III-IV evidence. Preferential TBI dose in children is 12-14.4 Gy in 1.6-2 Gy fractions b.i.d. Dose reduction should be considered for the lungs to <8 Gy, for the kidneys to ≤10 Gy, and for the lenses to <12 Gy, for dose rates ≥6 cGy/min. Highly conformal techniques i.e. TomoTherapy and VMAT TBI or Total Marrow (and/or Lymphoid) Irradiation as implemented in several centers, improve dose homogeneity and organ sparing, and should be evaluated in studies. CONCLUSIONS: These ESTRO ACROP SIOPE recommendations provide expert consensus for conventional and highly conformal myeloablative TBI in children, as well as a supporting literature overview of TBI techniques and toxicities.

Elevated D-Dimer and acute pulmonary embolism in COVID-19 patients / Dímero-D elevado y tromboembolismo pulmonar agudo en pacientes con COVID-19

INTRODUCTION: It has been determined that patients with SARS-CoV-2 infection and severe pneumonia with elevated D-dimer values ​​can develop acute pulmonary thromboembolism (APE) as a complication, being one of the causes related to mortality in this group of patients. METHODS: A retrospective analysis of 12 patients diagnosed with SARS-CoV-2 infection with high clinical suspicion of APE confirmed by computed tomography pulmonary angiopgraphy (CTPA) was performed and the described findings are described. RESULTS: 12 patients with diagnosis of severe pneumonia, elevated D-dimer 9.2 μg / ml (1.4 - ˃20 μg / mL) and confirmation of SARS-CoV-2 infection through real-time reverse transcription polymerasa chain reaction (RT-PCR). APEs were observed mainly in segmental arteries (75%) and main arteries (25%). Pneumonia with patched areas of bilateral ground glass opacities was observed in 100% of the sample as a typical finding of SARS-CoV-2 infection. CONCLUSION: SARS-CoV-2 infection is related to elevation of D-dimer and APE. The CTPA determines the diagnosis, severity and timely management (anticoagulation) of patients with APE. Therefore CTPA should be considered in all patients with elevated D-dimer or clinical worsening

INTRODUCCIÓN: Se ha determinado que los pacientes con infección por SARS-CoV-2 y neumonía severa con valores elevados de dímero-D, pueden desarrollar tromboembolismo pulmonar agudo (TEP) como complicación, siendo una de las causas relacionada con la mortalidad en este grupo de pacientes. MATERIAL Y MÉTODOS: Se realizó un análisis retrospectivo de 12 pacientes con diagnóstico de infección por SARS-CoV-2 con alta sospecha clínica de APE confirmado por angio tomografia computarizada (AngioTC) y se describen los hallazgos descritos. RESULTADOS: 12 pacientes con diagnóstico de neumonía severa, dímero-D elevado 9,2 μg/ml (1,4 - ˃20 μg/ml) y confirmación de infección de SARS-CoV-2 a través de reacción en cadena de polimerasa reversa (RT-PCR). Se objetivaron TEP principalmente en arterias segmentarias (75%) y arterias principales (25%). En el 100% de la muestra se objetivó neumonía con áreas parcheadas de vidrio deslustrado bilaterales como hallazgo típico de infección por SARS-CoV-2. CONCLUSIÓN: La infección por SARS-CoV-2 está relacionada con elevación del dímero-D y con TEP. La angioTC determina el diagnóstico, severidad y manejo oportuno (anticoagulación) de los pacientes con TEP. Por tanto el angioTC debe ser considerado en todos los pacientes con dímero-D elevado o empeoramiento clínico

Relación entre marcadores hematológicos y la respuesta patológica completa al tratamiento neoadyuvante en cáncer de recto localmente avanzado / Relationship between haematological markers and patological complete response to neoadjuvant treatment in locally advanced rectal cancer

INTRODUCCIÓN: Múltiples marcadores hematológicos de inflamación pueden tener relación con un peor pronóstico en los pacientes oncológicos. PROPÓSITO: Este estudio evaluó si los cambios en marcadores hematológicos antes y después del tratamiento quimio-radioterápico (QT-RT) en cáncer de recto pueden estar asociados con la respuesta patológica completa. MATERIAL Y MÉTODO: Se revisaron retrospectivamente las historias clínicas de 140 pacientes con cáncer de recto que recibieron tratamiento radioterápico neoadyuvante seguido de resección quirúrgica fueron revisados retrospectivamente. Se realizó analítica completa antes y después del tratamiento QT-RT. Se evaluaron leucocitos, hemoglobina, neutrófilos, linfocitos, monocitos, ratio neutrófilo-linfocitos (NLR), ratio plaqueta-linfocitos (PLR) y ratio linfocitos-monocitos (LMR). RESULTADOS: La respuesta patológica completa fue de 17,5%. Los marcadores hematológicos tuvieron una disminución significativa tras el tratamiento de QT-RT (p < 0,05), sin embargo en nuestro análisis no se relacionó con la respuesta patológica completa, salvo el PLR (p = 0,027). CONCLUSIÓN: Los marcadores hematológicos antres y después del tratamiento neoadyuvante no predicen la respuesta tumoral tras QT-RT en este estudio. Sin embargo una muestra mayor puede presentar resultados estadísticamente signifiacativos, especialmente con los monocitos

INTRODUCTION: Multiple haematological markers of inflammation might be related with poor prognosis in oncological patients. PURPOSE: This study evaluated whether changes of haematological markers before and after chemo-radiotherapy treatment in rectal cancer might be associated to pathological complete response. MATERIAL AND METHODS: Medical records of 140 patients with rectal cancer who received neoadjuvant radiotherapy followed by surgical resection were retrospectively review. Complete bloods counts (CBC) was measured days before and after period of RT. We assessed white blood cells count (WBC), hemoglobin levels (Hb), neutrophils count, lymphocytes count, monocytes count, neutrophil-to-lymphocye ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR). RESULTS: The overall rate of pCR was 17,5%. Hematological markers had a statistically significant decrease after CRT treatment (p < 0,05), however in our analysis they do not predict complete pathological response. CONCLUSION: Haematological markers before and after neoadjuvant treatment do not predict tumor responses in this study. However, a larger sample can show statistically significant results, especially in monocytes ratio

Quimioradioterapia en cáncer de recto y tasa de respuesta patológica / Chemoradiotherapy in rectal cancer and pathological response

INTRODUCCIÓN: El tratamiento neoadyuvante con radioterapia y quimioterapia radiosensibilizante en el cáncer de recto localmente avanzado (CRLA) disminuye significativamente las tasas de recurrencia local. Por tanto el objetivo de este estudio es analizar la respuesta patológica completa (RPC) y parcial (RPP) tras el tratamiento neoadyuvante con quimioradioterapia en pacientes con CRLA. MATERIAL Y MÉTODO: Se realizó un estudio descriptivo, retrospectivo en pacientes con diagnóstico de CRLA desde enero 2016 a diciembre 2018 en el Servicio de Oncología-Radioterápica del Hospital Universitario La Paz. Se incluyeron 140 pacientes. Un grupo de pacientes (92,9%) se trató con radioterapia 3D conformada con una dosis de 45Gy sobre pelvis y una sobreimpresión de 5,4Gy sobre tumor primario y otro grupo (7,1%) se trató con radioterapia con técnica volumétrica y en arcoterapia (VMAT) guiado por imagen (IGRT) con una dosis de 53,7Gy en pelvis con sobreimpresión concurrente al tumor. La dosis de capecitabina oral fue de 850mg/m2 dos veces al día durante el tratamiento. Todos los pacientes fueron reevaluados con resonancia magnética (RM) post-neoadyuvancia. Los pacientes se operaron entre 6-8 semanas tras quimioradioterapia. RESULTADOS: Se obtuvo una RPC de 17,1% y RPP de 80,1% con una tasa global de downstaging de 31,8%. CONCLUSIÓN: Se concluye que la quimioradioterapia neoadyuvante es un tratamiento seguro con aceptables tasas de control local en los pacientes con CRLA

INTRODUCTION: Neoadjuvant treatment with radiotherapy and radiosensitizing chemotherapy in locally advanced rectal cancer (LARC) significantly decreases local recurrence rates. Therefore the objective of this study is to analyze the pathological complete response (PCR) and partial response (PPR) of neoadjuvant treatment with exclusive chemoradiotherapy in patients with locally advanced rectal cancer. MATERIAL AND METHOD: It has been made a study descriptive, retrospective in a cohort of patients with LARC in the January 2016 to December 2018 period in the Radiation-Oncology Department of Hospital Universitario La Paz. 140 patients were included. A group of patients (92,9%) received treatment with radiotherapy 3D conformed technique with a dose administered the 45 Gy on pelvis and a boost of 5,4 Gy on tumor and other group (7,1%) received treatment with volumetric archotherapy radiotherapy (VMAT) guided by image (IGRT) with a dose administered of 53,7% on pelvis with concurrent boost and. The dose of capecitabine was 850 mg/m2, twice a day during the treatment. The patients were re-evaluated with post-neoadjuvant MRI. Patients were operated 6 to 8 weeks post chemoradiotherapy. RESULTS: CPR was obtained of 17,1% and pPR of 80,1% with a global rate downstaging of 31,8%. CONCLUSION: It concludes that chemoradiotherapy neoadjuvant is a safe treatment with acceptable rates of local control in patients with LARC

Valores de referencia de grasas para la población venezolana / Reference values of fats for the Venezuelan population

El presente trabajo es una revisión de la información disponible en la literatura científica en materia de alimentación y nutrición humana relacionada con las grasas y aceites. El objetivo es aportar una serie de orientaciones acerca de las recomendaciones nutricionales en la preñez, lactancia, niñez y adultez, para mejorar la salud y lograr el bienestar nutricional. Los temas tratados son: características de los ácidos grasos, requerimientos y recomendaciones relativas a su consumo y su impacto en la salud, situación en Venezuela y recomendaciones nutricionales. Se presentan las recomendaciones para las grasas totales y ácidos grasos en grupos de diferente edad y condiciones biológicas Se observó que según la distribución del consumo de grasas por alimento de la población venezolana el aporte de energía (28,84%) se encontró acorde con las recomendaciones de la FAO/WHO, 2010. Las grasas vegetales contribuyen con 62,60% de la grasa total y la fuente principal son los aceites vegetales (83,97%) seguido por los cereales (21,47%) el resto es aportado por vegetales, legumbres, hortalizas y otros. Mientras que las grasas de origen animal representan 36,84% de la grasa total y los principales alimentos fuentes son la leche y los lácteos que contribuyen con el mayor porcentaje (47,43%) seguido de las carnes y pescados (41,07%), y un menor aporte de los huevos (2,07%). Esto sugiere una alta relación n-6/n-3 dentro de las condiciones de alimentación general del venezolano, siendo necesario buscar vías que permitan disminuir esta relación, a fin de prevenir la enfermedad cardiovascular.

The present work is a review of the available information in the scientific literature in food and human nutrition related to fats and oils, in order to bring a range of guidance on nutritional requirements in pregnancy, infancy, childhood and adulthood, in improving the health and nutritional well-being. Topics include: characteristics of fatty acids, nomenclature, requirements and recommendations regarding their consumption and its impact on the health situation in Venezuela and recommendations. We present recommendations for total fat requirements and the different fatty acids for different age groups and biological conditions. It was noted that depending on the distribution of fat intake by food of the Venezuelan population energy intake (28.84%) is in line with the recommendations of the FAO / WHO, 2010. Vegetable fats contribute about 62.60% of the total fat where the main source are oils (83.97%) followed by cereals (21.47%) the rest is contributed by vegetables, legumes, vegetables and others. While animal fats represent a 36.84% Total chiffon, where milk and dairy products account for the highest percentage (47.43%) followed by meat and fish (41.07%), and a lower contribution from eggs (2.07%). This suggests a high ratio n-6/n-3 in feeding conditions Venezuelan general, being necessary to consider ways in which diminish this relationship, in order to prevent cardiovascular disease.