LATIN AMERICAN IMAGE QUALITY SURVEY IN DIGITAL MAMMOGRAPHY STUDIES.

Under International Atomic Energy Agency regional programme TSA3 Radiological Protection of Patients in Medical Exposures, Latin American countries evaluated the image quality and glandular doses for digital mammography equipment with the purpose of seeing the performance and compliance with international recommendations. Totally, 24 institutions participated from Brazil, Chile, Costa Rica, El Salvador, Mexico, Paraguay and Venezuela. Signal difference noise ratio results showed for CR poor compliance with tolerances; better results were obtained for full-field digital mammography equipment. Mean glandular dose results showed that the majority of units have values below the acceptable dose levels. This joint Latin American project identified common problems: difficulty in working with digital images and lack of specific training by medical physicists from the region. Image quality is a main issue not being satisfied in accordance with international recommendations; optimisation processes in which the doses are increased should be very carefully done in order to improve early detection of any cancer signs.

Latin American dose survey results in mammography studies under IAEA programme: radiological protection of patients in medical exposures (TSA3).

Latin American countries (Argentina, Brazil, Chile, Costa Rica, Cuba, Ecuador, El Salvador, Guatemala, Mexico, Nicaragua, Paraguay, Uruguay and Venezuela) working under the International Atomic Energy Agency (IAEA) Technical Cooperation Programme: TSA3 Radiological Protection of Patients in Medical Exposures have joined efforts in the optimisation of radiation protection in mammography practice. Through surveys of patient doses, the region has a unique database of diagnostic reference levels for analogue and digital equipment that will direct future optimisation activities towards the early detection of breast cancer among asymptomatic women. During RLA9/057 (2007-09) 24 institutions participated with analogue equipment in a dose survey. Regional training on methodology and measurement equipment was addressed in May 2007. The mean glandular dose (DG) was estimated using the incident kerma in air and relevant conversion coefficients for both projections craneo caudal and mediolateral oblique (CC and MLO). For Phase 2, RLA9/067 (2010-11), it was decided to include also digital systems in order to see their impact in future dose optimisation activities. Any new country that joined the project received training in the activities through IAEA expert missions. Twenty-nine new institutions participated (9 analogue and 20 digital equipment). A total of 2262 patient doses were collected during this study and from them D(G) (mGy) for both projections were estimated for each institution and country. Regional results (75 percentile in mGy) show for CC and MLO views, respectively: RLA9/057 (analogue) 2.63 and 3.17; RLA/067: 2.57 and 3.15 (analogue) and 2.69 and 2.90 (digital). Regarding only digital equipment for CC and MLO, respectively, computed radiography systems showed 2.59 and 2.78 and direct digital radiography (DDR) systems 2.78 and 3.04. Based on the IAEA Basic Safety Standard (BSS) reference dose (3 mGy), it can be observed that there is enough room to start optimisation processes in Latin America (LA); several countries or even particular institutions have values much higher than the 3 mGy. The main issues to address are lack of well-established quality assurance programmes for mammography, not enough medical physicists with training in mammography, an increase in patient doses with the introduction of digital equipment and to create awareness on radiation risk and optimisation strategies.

Determination of diagnostic reference levels in general radiography in Latin America.

The International Atomic Energy Agency (IAEA) through the International Action Plan on Radiation Protection of Patients and the International Commission on Radiological Protection have for some time carried out important efforts to assure that in the medical applications of the ionising radiations, the optimisation of radiological protection of patients is fundamental, to such a point that the IAEA includes it directly as a requirement for these practices (in its International Basic Safety Standards for Protection against Ionising Radiation and for the Safety of Radiation Sources (BSS)-GSR Part 1, 2011). For this reason, among the objectives of Regional Project RLA/9/057 and Regional Project RLA/9/067, the intention was to establish the dose references in conventional radiology for Latin America, for the purposes of determining whether these doses comply with the requirements of the BSS and to tend to improve practices, in order to minimise the dose received by the patients.

Braquiterapia intersticial de próstata / Interstitial brachytherapy of prostate

El cáncer de próstata representa un verdadero problema de salud pública, en nuestro país ocupa el primer lugar de incidencia de la población masculina. En los últimos años el enfoque terapéutico del cáncer de próstata ha sufrido el impacto de la revolución tecnológica. El objetivo de este trabajo es presentar el método utilizado en la terapia radical intersticial para estadios tempranos de carcinoma de próstata cuyo tamaño sea, menor de B1, es decir localizados dentro de la glándula prostática. El método consiste en la inserción de material radioactivo intralesional, se usan semillas de yodo 125, un isótopo de baja energía 35,5 KeV, con alcance en tejido de apenas 2 cm aproximadamente y 60 días de vida media, que es escogida porque permite de acuerdo con la experiencia clínica acumulada hasta el momento una mayor seguridad para el personal que trabaja con radiaciones, para los implantes permanentes es recomendable utilizar los de baja actividad. Las semillas son implantadas en la próstata de manera permanente, con el fin de administrar la dosis tumoral adecuada. Se describen los aspectos clínicos y de seguridad radiológica

Tumores del antro maxilar resultados con radioterapia / MAxillary sinus tumors result with radiotherapy

Se analizan 25 pacientes con tumores del antro maxilar tratados entre 1980-1998 60 por ciento (15/25) eran del sexo masculino, 40 por ciento (10/25) femenino. La mayoría se ubicó en el rango de edad entre los 60 y 69 años. 68 por ciento (17/25) fueron histológicamente epidermoides y entre ellos 41.17 por ciento (7/17) del tipo indeferenciado. Predominó la enfermedad localmente avanzada estadio III. Recibieron radioterapia la totalidad de los pacientes en 20 de ellos através de campo localizados ajustados a la extensión de la lesión, en cinco pacientes se incluyó el drenaje ganglionar. Se utilizó fraccionamiento convencional y energía proveniente de un acelerador lineal y una bomba de Co60, en pacientes usamos filtros y cuñas compensadoras. La tasa de RP fue del 60 por ciento (15/25) con complicaciones leves, 56 por ciento (14/25) recibieron QT como sensibilizante a la RT. La sobrevida actuarial global a los 3 y 5 años fue del 53 por ciento y 40 por ciento respectivamente. Aun trabajando con pacientes con enfermedad localmente avanzada con nuestra técnica de Rt logramos respuesta local y cifras de sobrevida similares a otras estadísticas mundiales. El uso de nuevos antineoplásicos y la adquisición de unidades de RT de última generación, unidos a campañas adecuadas de educación y prevención nos permitirán obtener mejor control local y mayores cifras de sobrevida en nuestros pacientes