Current uses and applications of stereotactic body radiation therapy.

Stereotactic body radiation therapy (SBRT) is a modality that delivers high doses of radiation to a well-defined tumor target in a single or a few fractions and with high precision, which significantly reduces the dose received by surrounding normal tissues. SBRT is indicated for inoperable, early stage (T1 and T2) primary non-small cell lung cancer, lung metastases with a controlled primary tumor, prostate tumors and oligometastatic disease. Despite the lack of long-term or phase III studies, efficacy results in local control are higher than 90%, with similar toxicity to that reported with conventional fractionated radiotherapy. This article describes SBRT technology and technique, along with clinical applications, indications and limitations of this therapeutic modality.

La radioterapia corporal estereotáctica es una modalidad que con alta precisión administra dosis alta de radiación a un objetivo tumoral bien definido, en una o en pocas fracciones, y reduce significativamente la dosis que reciben los tejidos sanos circundantes. Está indicada en cáncer primario de pulmón de células no pequeñas en estadios tempranos (T1 y T2) no operable, metástasis pulmonares con un tumor primario controlado, tumores prostáticos y enfermedad oligometastásica. A pesar de la falta de estudios a largo plazo o fase III, los resultados de su eficacia en el control local es superior a 90 %, con toxicidad similar a la reportada con fraccionamientos convencionales de radioterapia. Este artículo describe la tecnología y la técnica de radioterapia corporal estereotáctica, con las aplicaciones clínicas, indicaciones y limitaciones de esta modalidad terapéutica.

Voluntary breath-hold reduces dose to organs at risk in radiotherapy of left-sided breast cancer.

AIM: To compare the dose to organs at risk with free breathing (FB) or voluntary breath-hold (VBH) during radiotherapy of patients with left sided breast cancer. BACKGROUND: Radiotherapy reduces the risk of breast-cancer-specific mortality but the effects on other organs increase non-cancer-specific mortality. Radiation exposure to the heart, in particular in patients with left sided breast cancer, can be reduced by breath hold methods that increase the distance between the heart and the radiation field. MATERIALS AND METHODS: Three-dimensional conformal radiotherapy (3D-CRT) dose plans for the left breast and organs at risk including the heart, left anterior descending coronary artery (LAD) and ipsilateral lung were compared with FB and VBH in ten patients with left sided breast cancer. RESULTS: The mean doses to the heart and LAD were reduced by 50.4 % (p < 0.001) and 58.8 % (p = 0.006), respectively, in VBH relative to FB. The mean dose to the ipsilateral lung was reduced by 13.8 % (p = 0.11) in VBH relative to FB. The planning target volume (PTV) coverage was at least 95 % in both FB and VBH (p = 0.78). CONCLUSION: The VBH technique significantly reduces the dose to organs at risk in 3D-CRT treatment plans of left sided breast cancer.

Radiotherapy for the treatment of pituitary adenomas: A dosimetric comparison of three planning techniques.

AIM: Our goal was to compare conformal 3D (C3D) radiotherapy (RT), modulated intensity RT (IMRT), and volumetric modulated arc therapy (VMAT) planning techniques in treating pituitary adenomas. BACKGROUND: RT is important for managing pituitary adenomas. Treatment planning advances allow for higher radiation dosing with less risk of affecting organs at risk (OAR). MATERIALS AND METHODS: We conducted a 5-year retrospective review of patients with pituitary adenoma treated with external beam radiation therapy (C3D with flattening filter, flattening filter-free [FFF], IMRT, and VMAT). We compared dose-volume histogram data. For OARs, we recorded D2%, maximum, and mean doses. For planning target volume (PTV), we registered V95%, V107%, D95%, D98%, D50%, D2%, minimum dose, conformity index (CI), and homogeneity index (HI). RESULTS: Fifty-eight patients with pituitary adenoma were included. Target-volume coverage was acceptable for all techniques. The HI values were 0.06, IMRT; 0.07, VMAT; 0.08, C3D; and 0.09, C3D FFF (p < 0.0001). VMAT and IMRT provided the best target volume conformity (CI, 0.64 and 0.74, respectively; p < 0.0001). VMAT yielded the lowest doses to the optic pathway, lens, and cochlea. The position of the neck in extreme flexion showed that it helps in planning mainly with VMAT by allowing only one arc to be used and achieving the desired conformity, decreasing the treatment time, while allowing greater protection to the organs of risk using C3D, C3DFFF. CONCLUSIONS: Our results confirmed that EBRT in pituitary adenomas using IMRT, VMAT, C3D, C3FFF provide adequate coverage to the target. VMAT with a single arc or incomplete arc had a better compliance with desired dosimetric goals, such as target coverage and normal structures dose constraints, as well as shorter treatment time. Neck extreme flexion may have benefits in treatment planning for better preservation of organs at risk. C3D with extreme neck flexion is an appropriate treatment option when other treatment techniques are not available.

National Clinical Practice Guidelines for the management of non-small cell lung cancer in early, locally advanced and metastatic stages. Extended version. / Guía de Práctica Clínica Nacional para el manejo del cáncer de pulmón de células no pequeñas en estadios tempranos, localmente avanzados y metastásicos.

OBJECTIVE: Lung cancer is one the leading causes of mortality worldwide. Symptomatic manifestations of the disease generally occur in the advanced-stage setting, and therefore an important number of patients have advanced or metastatic disease by the time they are diagnosed. This situation contributes to a poor prognosis in the treatment of lung cancer. Evidencebased clinical recommendations are of great value to support decision-making for daily practice, and thus improving health care quality and patient outcomes. MATERIALS AND METHODS: This document was an initiative of the Mexican Society of Oncology (SMEO) in collaboration with Mexican Center of Clinical Excellence (Cenetec) according to Interna- tional Standards. Such standards included those described by the IOM, NICE, SIGN and GI-N. An interdisciplinary Guideline Development Group (GDG) was put together which included medical oncologists, surgical oncologistsc, radiation therapists, and methodologists with expertise in critical appraisal, sys- tematic reviews and clinical practice guidelines development. RESULTS: 62 clinical questions were agreed among members of the GDG. With the evidence identified from systematic reviews, the GDG developed clinical recommendations using a Modified Delphi Panel technique. Patients' representatives validated them. CONCLUSIONS: These Clinical Practice Guideline aims to support the shared decision-making process for patients with different stages of non-small cell lung cancer. Our goal is to improve health-care quality on these patients.

OBJETIVO: El cáncer de pulmón es una de las principales causas de mortalidad alrededor del mundo. Su historia natural, con la manifestación de síntomas en etapas avanzadas y el retraso en su diagnóstico hacen que una gran proporción de pacientes se diagnostiquen en estadios tardíos de la enfermedad, lo que hace muy complicado el tratamiento exitoso de la misma. De esto deriva la importancia de dar origen a recomendaciones basadas en evidencia para soportar la toma de decisiones clínicas por parte de los grupos interdisicplinarios que se encargan del manejo de este padecimiento. MATERIAL Y MÉTODOS: Este documento se desarrolló por parte de la Sociedad Mexicana de Oncología en colaboración con el Centro Nacional de Excelencia Tec- nológica de México (Cenetec) a través de la dirección de integración de Guías de Práctica Clínica en cumplimiento a estándares internacionales como los descritos por el Ins- tituto de Medicina de EUA (IOM, por sus siglas en inglés), el Instituto de Excelencia Clínica de Gran Bretaña (NICE, por sus siglas en inglés), la Red Colegiada para el Desarrollo de Guías de Escocia (SIGN, por sus siglas en inglés), la Red Internacional de Guías (G-I-N, por sus siglas en inglés); entre otros. Se integró en representación de la Sociedad Mexicana de Oncología un Grupo de Desarrollo de la Guía (GDG) de manera interdisciplinaria, considerando oncólogos médicos, cirujanos oncólogos, cirujanos de tórax, radio-oncólogos, y metodólogos con experiencia en revisiones sistemáticas de la literatura y guías de práctica clínica. RESULTADOS: Se consensuaron 62 preguntas cllínicas que abarcaron lo establecido previamente por el GDG en el documento de alcances de la Guía. Se identificó la evidencia científica que responde a cada una de estas preguntas clínicas y se evaluó críticamente la misma, antes de ser incorporada en el cuerpo de evidencia de la Guía. El GDG acordó mediante la técnica de consenso formal de expertos Panel Delphi la redacción final de las recomendaciones clínicas. C. CONCLUSIONES: Esta Guía de Práctica Clínica pretende proveer recomendaciones clínicas para el manejo de los distintos estadios de la enfermedad y que asistan en el proceso de toma de decisiones compartida. El GDG espera que esta guía contribuya a mejorar la calidad de la atención clínica en las pacientes con cáncer de pulmón de células no pequeñas.

The role of para-aortic nodal irradiation in cervical cancer.

The current standard of care for locally advanced cervical cancer is whole pelvis and para-aortic radiation when indicated, delivered concomitantly with chemotherapy and brachytherapy. Para-aortic node involvement is a predictor of survival in locally advanced disease but presence of metastases is difficult to determine because the currently available imaging methods lack enough sensitivity to be able to detect accurately para-aortic metastases when surgical staging is not feasible. The objective of this review is to describe the current status of para-aortic lymph node irradiation in locally advanced cervical cancer. It includes analysis of the diagnostic imaging and surgical approaches for assessment of para-aortic lymph node dissemination, together with indications for radiotherapy and radiotherapeutic techniques.

Usos y aplicaciones actuales de la radioterapia corporal estereotáctica / Current uses and applications of stereotactic body radiation therapy

Resumen La radioterapia corporal estereotáctica es una modalidad que con alta precisión administra dosis alta de radiación a un objetivo tumoral bien definido, en una o en pocas fracciones, y reduce significativamente la dosis que reciben los tejidos sanos circundantes. Está indicada en cáncer primario de pulmón de células no pequeñas en estadios tempranos (T1 y T2) no operable, metástasis pulmonares con un tumor primario controlado, tumores prostáticos y enfermedad oligometastásica. A pesar de la falta de estudios a largo plazo o fase III, los resultados de su eficacia en el control local es superior a 90 %, con toxicidad similar a la reportada con fraccionamientos convencionales de radioterapia. Este artículo describe la tecnología y la técnica de radioterapia corporal estereotáctica, con las aplicaciones clínicas, indicaciones y limitaciones de esta modalidad terapéutica.

Abstract Stereotactic body radiation therapy (SBRT) is a modality that delivers high doses of radiation to a well-defined tumor target in a single or a few fractions and with high precision, which significantly reduces the dose received by surrounding normal tissues. SBRT is indicated for inoperable, early stage (T1 and T2) primary non-small cell lung cancer, lung metastases with a controlled primary tumor, prostate tumors and oligometastatic disease. Despite the lack of long-term or phase III studies, efficacy results in local control are higher than 90%, with similar toxicity to that reported with conventional fractionated radiotherapy. This article describes SBRT technology and technique, along with clinical applications, indications and limitations of this therapeutic modality.