Recommendations for radiotherapy during the novel coronavirus pandemic

SUMMARY

Variación de dosis de radioyodo en pacientes con cáncer diferenciado de tiroides post implementación de guías ATA 2015 / Variation of radioiodine dose in patients with differentiated thyroid cancer after implementation of the ATA 2015 guidelines

Introducción: El cáncer diferenciado de tiroides (CDT), es actualmente la neoplasia endocrina más frecuente. Su tratamiento estándar es la resolución quirúrgica, asociado a ablación con radioyodo (RI) según la clasificación propuesta por la American Thyroid Association (ATA). Las indicaciones y dosis de este último, han ido variando en los últimos años según avanzan las investigaciones en este ámbito. Objetivo: En el siguiente estudio se compararon las dosis de RI utilizadas previo y posterior a la implementación de las últimas guías de la ATA. Materiales y métodos: Estudio retrospectivo observacional de 70 pacientes con diagnóstico de CDT del Hospital Clínico de la Universidad de Chile entre 2012 y 2017. Se agruparon los pacientes en dos cohortes, los operados entre los años 2012-2015 y los 2016-2017 clasificándolos según riesgo ATA, TNM y riesgo de recurrencia. Se consignaron las dosis de RI utilizadas y se compararon entre las cohortes. Análisis estadístico: Mann Whithney. Resultados: Al comparar la dosis de RI entre ambas cohortes, según TNM y riesgo ATA, se obtuvo los siguientes resultados: los pacientes T1b de la cohorte 2012-2015 presentaron dosis de RI significativamente mayores que los de la cohorte 2016-2017; también se evidenció que en pacientes N0 hubo una diferencia estadísticamente significativa, mostrando una tendencia a disminuir la dosis de RI; además, en los pacientes de la cohorte 2012-2015 con riesgo ATA intermedio, se obtuvo que las dosis de RI fueron significativamente mayores que las utilizadas en la cohorte 2016-2017. Conclusión: Se concluye que las variaciones de las dosis de RI utilizadas en pacientes con CDT en un hospital universitario van acorde a las recomendaciones internacionales actuales, particularmente la publicación de la guía ATA 2015, aplicándose radioablación con menor dosis de RI. Dado este cambio, se ha evidenciado igualdad de efectos con dosis menores de RI y consecuentemente menos efectos adversos.

Introduction: Differentiated thyroid cancer (CDT) is currently the most frequent endocrine neoplasia. Its standard of care is surgical treatment, associated with radioiodine ablation (IR) according to the classification proposed by the American Thyroid Association (ATA). The indications and doses of the latter have changed in recent years as research in this area advances. Objective: In the following study, the doses of IR used before and after the implementation of the latest ATA guidelines were compared. Materials and methods: Retrospective observational study of 70 patients with a diagnosis of CDT from the Clinical Hospital of the University of Chile between 2012 and 2017. Patients were grouped into two cohorts, those surgically intervened between the years 2012-2015 and 2016-2017, classifying them according to ATA risk, TNM and recurrence risk. The IR doses used were reported and compared between the cohorts. Statistical analysis: Mann Whithney. Results: When comparing the IR dose between both cohorts, according to TNM and ATA risk, the following results were obtained: T1b patients in the 2012-2015 cohort had significantly higher IR doses than those in the 2016-2017 cohort; It was also evidenced that N0 patients showed a statistically significant tendency to decrease the IR dose; In addition, the 2012-2015 cohort with intermediate ATA risk, revealed IR doses significantly higher than those used in the 2016-2017 cohort. Conclusion: It is concluded that the variations in IR doses, used in patients with CDT in a university hospital, are in accordance with current international recommendations, particularly the publication of the ATA 2015 guidelines, applying radioablation with a lower dose of IR. Given this change, equality of effects has been evidenced with lower doses of IR and consequently fewer adverse effects.

Regulacao dos servicos de radioterapia e quimioterapia pelas operadoras de planos de saude no Brasil / Regulation of radiotherapy and chemotherapy services by health plan organizations in Brazil

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Doses extracranianas em pacientes submetidos a radiocirurgia estereotáxica para tumores cerebrais / Extracranial doses in patients submitted to stereotactic radiosurgery for brain tumors

OBJETIVO: Estimar a dose extracraniana nos olhos, tireoide, tórax e pelve em pacientes submetidos a radiocirurgia com acelerador linear de 6 MV. MATERIAIS E MÉTODOS: Foram avaliados 11 pacientes com tumores cerebrais primários (7 pacientes) e secundários (4 pacientes), sendo que dois destes apresentavam duas lesões. Para a estimativa da dose extracraniana, foram utilizados dosímetros termoluminescentes. Foram utilizados cones de 1,50 a 3,75 cm e as doses de radiação variaram de 1300 a 2000 cGy. RESULTADOS: A idade média dos pacientes foi de 52 anos, sendo 63,6% do sexo feminino e 36,4% do sexo masculino. As localizações das lesões foram: nervo acústico direito (1), frontal (2), parietal (5), occipital direito (1), cerebelar (2) e parassagitais (2). Os valores médios das doses recebidas na região entre os olhos foram de 5,1 cGy; no olho direito, de 4,8 cGy; no olho esquerdo, de 6,5 cGy; na tireoide, de 4,2 cGy; no tórax, de 1,65 cGy; e na pelve, de 0,45 cGy. CONCLUSÃO: Estes resultados mostram que embora as doses não ultrapassem os limites de tolerância para ocorrência da opacidade do cristalino, é importante que os médicos radioterapeutas considerem os riscos de dose de radiação nessas regiões durante o planejamento de procedimentos de radiocirurgia craniana.

OBJECTIVE: To estimate extracranial doses on eyes, thyroid, chest and pelvis in patients submitted to radiosurgery with 6 MV linear accelerator. MATERIALS AND METHODS: The present study evaluated 11 patients, 7 of them with primary, and 4 with secondary brain tumors. In the latter group, 2 patients had two lesions. Thermoluminescent dosimeters were utilized to estimate the extracranial dose. Radiosurgery cones ranges between 1.50 and 3.75 cm and doses between 1300 and 2000 cGy. RESULTS: Mean patients' age was 52 years, and 63.6% of them were women and 36.4%, men. Lesion locations were the following: right acoustic nerve (1), frontal (2), parietal (5), right occipital (1), cerebellum (2) and parasagittal (2). Mean received doses were the following: 5.1 cGy between the eyes; 4.8 cGy in the right eye; 6.5 cGy in the left eye; 4.2 cGy in the thyroid; 1.65 cGy in the chest; and 0.45 cGy in the pelvis. CONCLUSION: The results demonstrate that that although the eye doses do not exceed the tolerance limits for occurrence of lens opacity, it is important that the risks associated with radiation doses are taken into consideration by radiotherapists in the planning of cranial radiosurgery procedures.

Las nuevas tecnologías: necesidades y retos en radioterapia en América Latina / New technologies: needs and challenges in radiotherapy in Latin America

La experiencia acumulada en más de un siglo de práctica de radioterapia ha puesto de manifiesto su importancia no solamente para la atención paliativa de una parte de los casos de cáncer, sino principalmente para la curación de una proporción aun mayor de esos pacientes. Teniendo en cuenta la evolución tecnológica, el acceso cada vez mayor que tienen los países en desarrollo a estos métodos y la cobertura actual en América Latina, los esfuerzos en esta área se deben dirigir a mejorar la calidad de los servicios y de los centros de radioterapia ya instalados. Para ello se debe completar su parque tecnológico, ampliar los servicios que prestan y cumplir los requerimientos mínimos de calidad establecidos para instalaciones del nivel 2. Cada centro debe estar en condiciones de realizar todas las etapas del proceso de radioterapia -desde la simulación hasta la verificación del tratamiento y el seguimiento de los pacientes- con una calidad adecuada (nivel 2). Para ello deben contar con la tecnología necesaria y con el personal debidamente capacitado. Los esfuerzos cooperativos en la Región deben tener también como prioridad contribuir a que los países adopten guías nacionales de tratamiento que contemplen todas las etapas del proceso de radioterapia y fomentar la puesta en marcha de programas validados de garantía de la calidad.

The cumulative experience gathered over more than a century of practice of radiotherapy has demonstrated the latter's importance not only for the palliative treatment of a fraction of cancer cases, but mainly for the curative treatment of an even greater proportion of such cases. In light of the changes in technology, the ever-increasing access developing countries to such technology, and its current coverage in Latin America, any efforts in this area should be aimed at improving the quality of the radiotherapy services and centers that are already in place. This involves developing their technological assets to the fullest, expanding their services, and complying with the minimum quality requirements established for second-level facilities. Each center should be equipped to carry out all stages of the radiotherapy process, from simulation through treatment verification and patient follow-up, with a high level of quality (level 2). To achieve this, it should possess the necessary technology and properly-trained staff that are required for the purpose. Collaborative efforts in the Region should also prioritize helping countries implement national treatment standards for all stages of the radiotherapy process and promoting the implementation of validated quality assurance programs.

Verification of radiation dose calculation for patients treated by Co-60 using 2-D planning system

In this study, experimental verifications is done for output, dose profile percentage depth dose for open and modified [wedged and partially blocked] fields as compared with the calculated using Multidata code. Four typical configurations of irradiation were selected, regular fields, wedged fields, blocked fields and cases of internal inhomogeneity. Measurements were performed on cobalt - 60 unit Theratron 780E using Multidata water phantom. For blocked fields dose profiles were measured using radiographic films and then scanned using PTW densitometer. Data were analyzed in both of the low and high dose gradient regions of the measured and calculated profiles. Differences between the measured and the calculated dose were determined. The results indicate that the Multidata planning system calculations agree with the measured ones in situations. However, in the blocked field the mean deviation between measured and calculated dose under the block was [15.2%] although the blocks is drown according to the instructions by the system manufactures. The reason for such errors was found to be due to the implemented algorithm in the system

Tumor neuroectodermal primitivo periférico o una variante de él? / Primitive neuroectodermal tumor or a variant?

Se presentan cuatro casos de tumor de Merkel en pacientes añosos, con evolución entre tres meses y un año. La inmunomarcación e histopatología fueron similares en todos. Dos estaban localizados en zonas expuestas al sol, y dos en áreas ocultas. Todos tenían situación subcutánea o corion mucoso, ninguno en relación con epitelios suprayacentes, dato que reforzaría nuestra sospecha de su origen en restos embrionarios de tejido neuroblástico. Todos evolucionaron mal, no obstante una terapéutica adecuada. El último se encuentra con metástasis ganglionares y viscerales

Proposición de consenso para el uso de yodo 131 en el tratamiento de la tirotoxicosis y el cáncer del tiroides / Consensus proposal on the use of iodine-131 in hyperthyroidism and thyroid cancer

A consensus meeting held by the Chilean Endocrinological Society reached to 22 consensus proposals on the use of iodine-131 in hyperthyroidism and thyroid cancer, that are reported in this paper. Some of these propositions are: 1) Hyperthyroidism: A previous 131I uptake test must be performed. A calculated or an ablative dose should be administered. Hypothyroidism must be considered an objective rather than a complication. In patients with cardiovascular risk, normal thyroid function must be attained with propythioturacil. In cases of treatment failure, the dose should not be repeated before six months. It must be used with used with caution in children and teenagers. 2) Thyroid cancer: A iodine free diet is recommended prior to the therapeutic dose. A 100 mCi complementary ablative dose should be given after surgery, with a posterior exploration. This examination must not be done routinely, and if required, a 5 mCi dose should be used. For the treatment of metastases, a dose of 150 to 200 mCi is recommended. There is no radiation risk in hyperthyroidism or thyroid cancer. The only absolute contraindication is pregnancy. Recommendations for radiological protection are formulated. Hospitalization is suggested to protect other people from radiation exposure

Radiotratamiento de Mafenida 10 por ciento Crema / Radiotreatment with mafenide 10 per center cream

La aplicacion de las radiaciones ionizantes con fines descontaminantes constituye una alternativa para garantizar la calidad microbiologica de muchas producciones farmaceuticas. Se realizo el radiotratamiento de mafenida 10 por ciento crema que no cumplia con las especificaciones de calidad microbiologica establecidas en el pais. Para ello se determino la carga microbiana y se realizo un estudio de dosis en el producto, evaluandose 3,5,7 y 10 KGy de radiaciones gamma, con el empleo de una fuente radioisotopica de Co(60). Se realizaron evaluaciones microbiologicas y quimicofisicas pretratamiento y postratamiento y se definio irradiar el producto con 3 KGy como dosis minima, de forma continua y en la instalacion "Producto-I" del Instituto de Investigaciones para la Industria Alimenticia

Manual de acreditación de hospitales / Manual for hospital accreditation

Contiene: Marco conceptual; Estándares de acreditación; Dirección; Administración; Epidemiología; Consulta externa; Emergencia; Hospitalización; Centro quirúrgico; Esterilización central; Centro obstétrico; Neonatología; Cuidados intensivos; Rehabilitación; Patología clínica; Banco de sangre; Anatomía patológica; Imágenes; Radioterapia; Medicina nuclear; Enfermería; Farmacia; Trabajo social; Nutrición y dietética; Registros médicos y estadística; Lavandería; Mantenimiento; Limpieza; Seguridad

Limb salvage for extremity sarcoma in Ramathibodi Hospital.

From May 1986 to July 1991, a retrospective review of 27 patients treated with limb salvage surgery for extremity sarcomas, was evaluated by our team. There were 12 males and 15 females with a mean age of 22.7 years (ranging from, 9 to 53 years). The mean of the follow-up period was 27.6 months. (ranging from 6 to 62 months). Twenty-four patients had bone sarcomas which included 20 osteosarcomas, 3 chondrosarcomas and one adamantinoma. The locations of bone sarcomas were the proximal tibia (6 cases), distal femur (5 cases), proximal humerus (4 cases), proximal fibula (3 cases), scapula (3 cases), proximal femur (1 case), tibial shaft (1 case) and pelvis (1 case). The remaining three patients had malignant fibrous histiocytomas located in scapular, tibialis anterior muscle, and knee regions. In total there were 1 stage IA, 2 stage Ib, 1 stage IIA and 23 stage IIB. Twenty-four cases had wide excisions; two had marginal excisions and one radical excision. There were 17 bone reconstructions consisting of 11 allografts and 6 autografts. At the most recent follow-up examination, 74 per cent of the patients are alive and the overall disease free survival was 63 per cent. Local recurrences occurred in 11 per cent. The major complication rate was 3 per cent and the minor complication rate was 33 per cent. With respect to a functional outcome, 84 per cent of the patients achieved excellent or good results.(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative mitomycin-C eye drop and beta radiation in the treatment of pterygia.

One hundred and forty-seven eyes (137 patients) with primary pterygia were treated with excision with additional therapy, and were followed up for three months to six years after treatment. Of 85 eyes that underwent excision and postoperative instillation of 0.02 per cent mitomycin-C, there were three which had corneal recurrence (3.5%) and four had conjunctival recurrence (4.7%). The other 62 eyes were treated with beta radiation, there were nine with corneal recurrence (14.5%) and three had conjunctival recurrence (4.8%). Adjunctive therapy with mitomycin-c eye drop reduced the recurrence rate significantly (P less than 0.1). Complications occurred in five eyes (6%) by using mitomycin-c eye drop which included allergic reaction, granulation mass and mild scleral necrosis. Two of 62 eyes (3%) treated with beta radiation had complications of granulation mass. We found that pterygium excision with mitomycin-c eye drop to be effective in prevention of recurrent pterygium.

Multidisciplinary "limb salvage" treatment of osteosarcoma.

Intraarterial plus systemic chemotherapy of cis-diamine dichloroplatinum-II and anthracycline together with preoperative radiation and "limb salvage" treatment have increased the chance of local control and facilitated the previous surgically nonresectable to be resectable. Among 30 cases of osteosarcoma from 1986-1989, aged 9-43 years old, 10 of the 17 cases (58.8%) are still alive with the mean disease free survival of 27.8 months. Late pulmonary metastases cause the need for future protocol for prophylactic lung therapy.

Nasopharyngeal carcinoma: results of treatment by radiotherapy vs chemotherapy plus radiotherapy.

To determine the efficacy of neoadjuvant chemotherapy over radiotherapy alone in locally advanced nasopharyngeal carcinoma, a prospective non-randomized study was performed from 1 January 1982 to 31 December 1985 at Ramathibodi Hospital, Thailand. There were 69 new cases who completed treatment and were followed up at least once. Thirty-three cases were treated by radical radiotherapy (RT) alone and 36 cases by chemotherapy (CT) + RT. CT were by the combination of cis-diamminedichloroplatinum II and 5 fluorouracil. Of 32 cases, 2 courses of CT were given before RT and 1 after. The other 4 received 3 courses prior to RT. For both groups, RT technique and dosage were similar. Follow-up time of both groups ranged from 6-104 months (mean 50.3, median 50) and 8-100 months (mean 52.2, median 54.5), and total failures were 18/33 and 13/36, respectively, with no statistical difference (p greater than 0.05). Estimated actual survival and disease free survival from Kaplan-Meier curves at 3 years were about 75 per cent vs 75 per cent and 65 per cent vs 65 per cent, respectively, with no statistical differences (Log-Rank test). Therefore, we concluded that induction chemotherapy had some benefit but no statistical significance over RT alone. However, the role of maintenance chemotherapy is now being studied.

role of medical physics in radiation therapy

A Key Role in all medical uses of ionizing radiation is played by the radiophysicist His responsibility includes the establishment and maintenance in collaboration, with the engineering hand of accurate methods of dosimetry for both therapy and protection purposes. The other responsibility is the development of physical technique, for many uses of radioactive isotopes. His special knowledge of radiation and electronics finds many-applications in diagnostic radiology. Collaboration with the radiotherapist in the development of new techniques or in the, study of several problems