Uso de PET-CT en el delineado de volumen en la planificación del tratamiento con radiación / Use of PET-CT in the one delineated of volume in the planning of the one radiant treatment

El tratamiento con radioterapia, consiste en irradiar de forma homogénea el tumor, evitando irradiar los órganos cercanos. El desarrollo de la tecnología en el campo de la medicina, ha permitido que se cumpla este principio, con buenos resultados de respuesta objetiva, que se traduce en el control de la enfermedad de los pacientes con cáncer. La Tomografía axial computarizada por emisión de positrones (PET-CT) consigue una mayor precisión en el delineado del volumen blanco o tumoral. El propósito de este estudio fue analizar la influencia del uso del PET-CT en el delineado de volúmenes a tratar en la planificación del tratamiento con radiaciones.Se diseñó un estudio piloto con dos pacientes preparados para radioterapia por neoplasias malignas, a los cuáles se les realizó un TAC simple y un PET-CT y observadores independientes realizaron la delimitación del tumor. Se examinó la consistencia entre los observadores y las mediciones en las imágenes.El uso del PET-CT favoreció la delimitación del volumen a irradiar lo que disminuye el riesgo para los órganos vecinos.

The treatment with radiotherapy consists on irradiating in a homogeneous way the tumor, avoiding to irradiate the near organs. The development of the technology in the field of the medicine, it has allowed that this principle is completed, with good results of objective answer what allows the control of the illness of the patients with cancer. The computerized axial tomography by positrons emission (PET-CT) it gets a bigger precision in the one delineated of the white volume or tumoral. The purpose of this study was to analyze the influence of the use of the PET-CT in the one delineated of volumes to try in the planning of the treatment with radiations.A study pilot was designed with two prepared patients for radiotherapy for malignant diseases, to those which they were carried out a simple TAC and a PET-CT and independent observers carried out the delimitation of the tumor. The consistency was examined between the observers and the mensuration in the images.The use of the PET-CT favors the delimitation of the volume to irradiate what diminishes the risk for the neighboring organs.

Radioprotective natural products as alternative complements in oncological radiotherapy / Productos naturales radioprotectores como complementos alternativos en la radioterapia oncológica

Humans when exposed to harmful ionising radiations suffer from various pathophysiological disorders including cancer. Radiotherapy is a treatment where these cancerous cells within a tumor aretargeted and killed by means of high energy waves. This therapy is very expensive and involves highly sophisticated instruments. In addition to this, most synthetic radioprotectors including Amifostine have been found to possess toxicity. This led researchers to develop a novel, economically viable, and efficient therapeutic alternative to radiation therapy. The last two decades have observed a major shift towards investigating natural products as radioprotectors, as these are immensely effective in terms of their potential bioequivalence relative to many of the established synthetic compounds available. Taking into account the limitations of radiation therapy, an approach 'Integrative Oncology' that involves a combination of both traditional and conventional medical treatment are used nowadays to treat patients suffering from cancer and associated mental and psychological disorders.

Los seres humanos, cuando se exponen a radiaciones ionizantes nocivas, sufren diversos trastornos fisiopatológicos, incluido el cáncer. La radioterapia es un tratamiento en el que estas células cancerosas dentro de un tumor son atacadas y destruidas por medio de ondas de alta energía. Esta terapia es muy cara e implica instrumentos muy sofisticados. Además de esto, se ha descubierto que la mayoría de los radioprotectores sintéticos, incluida la amifostina, poseen toxicidad. Esto llevó a los investigadores a desarrollar una novedosa, económicamente viable y eficiente alternativa terapéutica a la radioterapia. En las dos últimas décadas se ha observado un cambio importante hacia la investigación de productos naturales como radioprotectores, ya que son inmensamente eficaces en términos de su potencial bioequivalencia en relación con muchos de los compuestos sintéticos establecidos disponibles. Teniendo en cuenta las limitaciones de la radioterapia, hoy en día se utiliza un enfoque de "Oncología Integrativa" que implica una combinación de tratamiento médico tradicional y convencional para tratar a pacientes que padecen cáncer y trastornos mentales y psicológicos asociados.

La cardiooncología pediátrica como disciplina emergente en Cuba / Pediatric cardio-oncology as an emergent discipline in Cuba

El reconocimiento inicial de la disfunción cardíaca ocasionada por estrategias terapéuticas aplicadas contra el cáncer fue realizado en la sexta década del siglo xx. La Cardiooncología es una nueva disciplina horizontal dirigida a la identificación de los pacientes en riesgo elevado para el desarrollo de toxicidad cardíaca. El eficaz desempeño inherente a la Cardiooncología pediátrica radica en la adecuada selección del medio diagnóstico capaz de identificar y evaluar los indicios de cardiotoxicidad mediante la detección de cambios precoces en la funcionalidad del miocardio tras la aplicación de terapias antitumorales y, sobre todo, la predicción a largo plazo de estos eventos en niños sobrevivientes de cáncer. La cardiotoxicidad secundaria a la terapéutica aplicada sobre estos pacientes es un problema de salud latente en nuestro país que precisa la adopción de medidas organizativas concebidas para su enfrentamiento. Se persigue contribuir a la estructuración de la atención integral correspondiente al niño con cáncer y afectado por cardiotoxicidad en Cuba(AU)

The initial recognition of cardiac dysfunction caused by therapeutic strategies applied against cancer was performed in the sixth decade of the twentieth century. Cardio-Oncology is a new horizontal discipline aimed at the identification of patients at high risk for the development of cardiac toxicity. The effective performance inherent in Pediatric cardio-oncology lies in the appropriate selection of the diagnostic mean which can be capable of identifying and evaluating the indications of heart toxicity by detecting early changes in myocardial functionality after the application of anti-tumour therapies and, above all, the long-term prediction of these events in children survivors of cancer. Cardiac toxicity secondary to the therapies applied on these patients is a latent health problem in our country that requires the adoption of organisational measures conceived for their confrontation. It is pursued to contribute to the structuring of the comprehensive care corresponding to children with cancer and affected by cardiotoxicity in Cuba(AU)

Is moderate hypofractionation accepted as a new standard of care in north america for prostate cancer patients treated with external beam radiotherapy? Survey of genitourinary expert radiation oncologists

ABSTRACT Introduction: Several recent randomized clinical trials have evaluated hypofractionated regimens against conventionally fractionated EBRT and shown similar effectiveness with conflicting toxicity results. The current view regarding hypofractionation compared to conventional EBRT among North American genitourinary experts for management of prostate cancer has not been investigated. Materials and Methods: A survey was distributed to 88 practicing North American GU physicians serving on decision - making committees of cooperative group research organizations. Questions pertained to opinions regarding the default EBRT dose and fractionation for a hypothetical example of a favorable intermediate - risk prostate cancer (Gleason 3 + 4). Treatment recommendations were correlated with practice patterns using Fisher's exact test. Results: Forty - two respondents (48%) completed the survey. We excluded from analysis two respondents who selected radical hypofractionation with 5 - 12 fractions as a preferred treatment modality. Among the 40 analyzed respondents, 23 (57.5%) recommend conventional fractionation and 17 (42.5%) recommended moderate hypofractionation. No demographic factors were found to be associated with preference for a fractionation regimen. Support for brachytherapy as a first choice treatment modality for low - risk prostate cancer was borderline significantly associated with support for moderate hypofractionated EBRT treatment modality (p = 0.089). Conclusions: There is an almost equal split among North American GU expert radiation oncologists regarding the appropriateness to consider moderately hypofractionated EBRT as a new standard of care in management of patients with prostate cancer. Physicians who embrace brachytherapy may be more inclined to support moderate hypofractionated regimen for EBRT. It is unclear whether reports with longer follow-ups will impact this balance, or whether national care and reimbursement policies will drive the clinical decisions. In the day and age of patient - centered care delivery, patients should receive an objective recommendation based on available clinical evidence. The stark division among GU experts may influence the design of future clinical trials utilizing EBRT for patients with prostate cancer.

Can positron emission tomography be more than a diagnostic tool? A survey on clinical practice among radiation oncologists in India.

AIM: The purpose of the survey was to understand the role of positron emission tomography (PET) in clinical radiotherapy practice among the radiation oncologists’ in India. SETTINGS AND DESIGN: An online questionnaire was developed to survey the oncologists on their use of PET, viewing protocols, contouring techniques practiced, the barriers on the use of PET and the need for training in use of PET in radiotherapy. The questionnaire was sent to about 500 oncologists and 76 completed responses were received. RESULTS: The survey shows that radiation oncologists use PET largely to assess treatment response and staging but limitedly use it for radiotherapy treatment planning. Only manual contouring and fixed threshold based delineation techniques (e.g. 40% maximum standard uptake value [SUVmax] or SUV 2.5) are used. Cost is the major barrier in the wider use of PET, followed by limited availability of FDG radionuclide tracer. Limited or no training was available for the use of PET. CONCLUSIONS: Our survey revealed the vast difference between literature suggestions and actual clinical practice on the use of PET in radiotherapy. Additional training and standardization of protocols for use of PET in radiotherapy is essential for fully utilizing the capability of PET.

Radioterapia hipofraccionada en el tratamiento preservador del cáncer de mama en estadio precoz resultados preliminares / Hypo fraction radiation therapy in the preserved tratment of early breast cancer

Resultados preliminares del tratamiento con radioterapia hipofraccionada, en pacientes con cáncer de mama en estadio precoz, y cirugía preservadora. Análisis retrospectivo de 64 pacientes estadios 0, I y II, ganglios negativos, tratadas entre marzo 2009 abril 2011. Tratamiento con planificación conformada tridimensional, dosis de 42,6 Gy en 16 fracciones de 2,66 Gy a toda la mama, más dosis adicional de 7,98 Gy en 3 fracciones al lecho del tumor primario. La distribución por estadios fue: estadio 0 15/ 64 pacientes 23,4%; estadio I 41/64 64,1%, estadio II 8/64 12,6%. Seguimiento de 1 a 2,3 meses, promedio 4,4 meses. Todas las pacientes se encuentran vivas, libres de enfermedad hasta el momento. Complicaciones agudas: 85,94 radiodermatitis grado 0-I (55/64), 7,81% radiodermatitis grado II (5/64),3,1% grado III (2/64) y 2 pacientes no fueron evaluables, 6-24 meses después de finalizar la irradiación, 53,1% no presentó complicaciones, 32,8% (21/64) presentaron radiodermatitis grado I (eritema, hiperpigmentación), 1,6% (1) dermatitis grado II, 2 pacientes dermatitis grado III,6/64 (9,3%). 3 estudios aleatorios han demostrado la efectividad de los regímenes de hipofraccionamiento, resultados comparables a los esquemas de fraccionamiento convencional. Los resultados preliminares, nos animan a continuar el empleo de estos esquemas de radioterapia en la práctica clínica. Es necesario un mayor tiempo de seguimiento en la serie de pacientes presentadas, para evaluar los resultados de control local, sobrevida y morbilidad tardía por radioterapia

Preliminary results obtained with hypo fractionated radiotherapy in patients with early breast cancer who have undergone breast conserving surgery. Retrospective analysis 64 patients treated from March 2009- April 2011. Treated with 3D conformal radiation therapy; dose 42.6 Gy in 16 fractions 2.66 Gy was given to the breast followed by a boost to tumor bed of 7.98 Gy in 3 fractions. Distribution according to stage was: Stage 0 15/64 patients 23.4%; stage I 41/64 64.1% and stage II 8/64 12.6%. Mean follow up 4, 4 months, with range 1 to 2.3 months. All patients are alive and free of disease, at moment analysis the data. Acute complications: Grade 0-1 skin reactions 85.94% (55/64 ), grade II 7.81% (5/64 ), grade III 3,1% (2/64), 2 patients could not be evaluated. 6-24 months after completion treatment 53,1% had no complications; 32.8% (21/64) grade I dermatitis (Erythema, hyper pigmentation); 1.6% (1) grade II, 2 patients grade III dermatitis, 6/64 patients (9.3%) there was mild subcutaneous fibrosis. 3 randomized clinical trials, regimens of hypo fraction y have produced results comparable to conventional fractionation. The preliminary results of this study are encouraging; we continue to apply this regimen in the clinical practice. Obviously a longer follow up time is necessary to determine results regarding survival, local control and chronic complications of radiotherapy in the present study

The role of intensity-modulated radiotherapy in head and neck cancer.

Intensity-modulated radiotherapy (IMRT) has been a significant technological advance in the field of radiotherapy in recent years. IMRT allows sparing of normal tissue while delivering radical radiation doses to the target volumes. The role of IMRT for parotid salivary gland sparing in head and neck cancer is well established. The utility of IMRT for pharyngeal constrictor muscle and cochlear sparing requires investigation in clinical trials. The current evidence supporting the use of IMRT in various head and neck subsites has been summarized. Sparing of organs at risk allows for dose-escalation to the target volumes, taking advantage of the steep dose-response relationship for squamous cell carcinomas to improve treatment outcomes in advanced head and neck cancers. However, dose-escalation could result in increased radiation toxicity (acute and late), which has to be studied in detail. The future of IMRT in head and neck cancers lies in exploring the use of biological imaging for dose-escalation using targeted dose painting.

Non-FDG PET in the practice of oncology.

Fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET) is utilized in more than 90% of cancers in staging, re-staging, assessing therapy response and during the follow-up. However, not all tumors show significant increase of metabolic activity on FDG-PET imaging. This is particularly true for prostate cancer, neuroendocrine tumors and hepatic tumors. In this review we have considered those already used for clinical applications such as 11C- and 18F-Choline, 11C-Methionine and 18F-FET, 18F-DOPA, 68Ga-DOTA-somatostatine analogues, 11C-Acetate and 18F-FLT. Choline presents a high affinity for malignant prostate tissue, even if low grade. Choline can be labeled with either 11C or 18F, the former being the preference due to lower urinary excretion and patients exposure. The latter is more useful for possible distribution to centers lacking in on-site cyclotron. Methionine is needed for protein synthesis and tumor cells require an external supply of methionine. These tracers have primarily been used for imaging of CNS neoplasms. The most appropriate indication is when conventional imaging procedures do not distinguish between edema, fibrosis or necrosis and disease relapse. In addition, the uptake of 11C-Methionine is proportional to the tumor grade and, therefore, the maximum small unilamellar vesicles (SUV) inside the brain mass before therapy is somehow considered a prognostic value. Neuroendocrine tumors (carcinoids, pheocromocytoma, neuroblastoma, medullary thyroid cancer, microcytoma, carotid glomus tumors, and melanoma) demonstrate an increased activity of L-DOPA decarboxylase, and hence they show a high uptake of 18FDOPA. For the study of NETs, 68Ga-DOTA-TOC/DOTA-NOC has been introduced as PET tracer. This compound for PET imaging has a high affinity for sst2 and sst5 and has been used in the detection of NETs in preliminary studies; 68Ga-DOTA-NOC PET is useful before metabolic radiotherapy in order to evaluate the biodistribution of the therapeutic compound; 18F-FLT is a specific marker of cell proliferation and the most important field of application of FLT is lung cancer. Other tracers are used in PET utilized as markers of hypoxia inside big neoplastic masses include 18F-MISO, 64Cu-ATSM, 18F-EF5, which highlight the presence of hypoxic areas are useful for patients that must be treated with radiotherapy.

Primer caso de preservación de fertilidad en Guatemala / First case of preservation of fertility in Guatemala

La sobrevida a largo plazo de las pacientes con patología oncológica se ha incrementado en las últimas décadas, gracias a la detección temprana y a los avances en la terapia oncológica. Esta condición cada vez es mayor en mujeres que se encuentran en edad fértil, y que aún no han considerado su deseo gestacional. Se sabe muy bien que la terapia oncológica es tóxica para las gónadas, efecto que dependerá del medicamento, dosis, empleo de radioterapia y de edad de administración del tratamiento...

Clinical Characteristics of Radiation Oncology in Korea during Past 10 Years

To understand trends in the clinical characteristics of radiation oncology over the last 10 yr in Korea, annual survey questionnaires were sent to all of Korean radiation oncology facilities since 1990. Questionnaires addressed basic radiation therapy facilities and the clinical information. Responses were obtained from all facilities, and data collected from 1997 to 2006 was analyzed. The numbers of new patients that have undergone radiation therapy and the numbers of hospitals with a department of radiation oncology have steadily increased over the past 10 yr, and totaled 37,215 patients and 60 hospitals, respectively, in 2006. However, the proportion of patients irradiated among total cancer patients has remained below 30% over the last 10 yr. The numbers of prostate cancer, breast cancer, and hepatoma have increased by more than 3 fold over the past 10 yr. Moreover, the percentage of irradiated patients treated by brachytherapy was 10.3% in 1997, but this gradually fell to only 4.2% in 2006. The information collected described the role played by radiation oncology in Korea. Continuous surveys are required to enable trends to be detected.

La radioterapia: ¿Tratamiento sistémico? / The radiotherapy: Systemic treatment?

La radioterapia como modalidad terapéutica oncológica se usa extensivamente para el control locorregional de un sinnúmero de neoplasias sólidas y hematológicas. Sin embargo, también puede hablarse de radioterapia como una terapia sistémica cuando ésta se usa en grandes áreas corporales. La presente revisión resume el enfoque actual, la experiencia y la aplicación de la radioterapia sistémica en nuestro medio