X-radiation does not affect the dental pulp: a morphological study in rats / A radiação X não afeta a polpa dentária: um estudo morfológico em ratos

Introduction: Radiotherapy is one of the methods used as a treatment for malignant tumors in the head and neck region and it can cause tissue damage in the irradiated areas. In head and neck radiotherapy, teeth are often included within the irradiation area and, consequently, the dental pulp; which receives high doses of radiation. Objective: To evaluate the effects of ionizing radiation on the pulp tissue of rat teeth. Methodology: A double-blind experimental assay with 35 Albinus Wistar rats divided into seven groups was performed; one control group, three groups irradiated with 15 Gy, and three groups irradiated with 25 Gy. The irradiated groups were submit-ted to a single dose of radiation and sacrificed 24 hours, 7 days, and 22 days after irradiation, respectively. The samples were evaluated for the morphological presence of inflammatory infiltrate, edema, necrosis, fibrosis, and degeneration of blood vessels. Statistical analysis was performed using the Kruskal-Wallis and Dunn tests with p < 0.05. Results: Hyaline degeneration of the pulp blood vessels in the irradiated teeth was statistically signifi-cant in all irradiated groups. Inflammatory infiltrate, edema, necrosis or fibrosis was not observed. Conclusion:A single X-radiation dose is not able to affect the dental pulp connective tissue in the long term with no clinical damage.

Introdução: A radioterapia é um dos métodos utilizados como tratamento para tumores malignos em região de cabeça e pescoço e que pode causar danos aos tecidos nas áreas irradiadas. Na radioterapia de cabeça e pescoço, os dentes são comumente incluídos dentro da área de radiação e, consequentemente, a polpa dentária, recebe altas doses de radiação. Objetivo: Avaliar os efeitos da radiação ionizante no tecido pulpar de dentes de ratos. Metodologia: Foi realizado um ensaio experimental duplo-cego com 35 ratos Albinus Wistar divididos em sete grupos: um grupo controle, três grupos irradiados com 15 Gy e três grupos irradiados com 25 Gy. Os grupos irradiados foram submetidos a uma dose única de radiação e sacrificados 24 horas, 7 dias e 22 dias após a irradiação, respectivamente. As amostras foram avaliadas quanto à presença morfológica de infiltrado inflamatório, edema, necrose, fibrose e degeneração nos vasos sanguíneos. A análise estatística foi realizada por meio dos testes de Kruskal-Wallis e Dunn com p < 0.05. Resultados: Degeneração hialina nos vasos sanguíneos pulpares dos dentes irradiados foi estatisticamente significante em todos os grupos irradiados. Não foi observado infiltrado inflamatório, edema, necrose ou fibrose. Conclusão: Uma dose única de radiação X não é capaz de afetar o tecido conjuntivo da polpa dentária a longo prazo sem danos clínicos.

Evaluación imaginológica de un caso de histiocitosis durante tres años / Imaging evaluation of a case of histiocytosis for three years

La histiocitosis de células de Langerhans es un trastorno celular dendrítico, resultado de la proliferación clonal de este tipo de células, morfológicamente redondeadas e inmaduras inmunofenotípica y funcionalmente; asociadas con eosinófilos, macrófagos, linfocitos y células multinucleadas gigantes, en ocasiones. Puede presentarse de forma monosistémica, cuando afecta a un solo sitio u órgan; o multisistémica cuando se presenta en múltiples órganos o sistemas corporales. La literatura médica y las publicaciones en las que se asocia la imaginología al estudio y caracterización de las enfermedades hematológicas son escasas, aun en la era tecnológica. En este trabajo se presenta un caso de histiocitosis de células de Langerhans que fue seguido imaginológicamente durante 3 años con el consiguiente apoyo al diagnostico, tratamiento, seguimiento y valoración; lo que demuestra la utilidad de la Imaginología como herramienta para lograr un mejor manejo del paciente y como principio de la atención medica multidisciplinaria(AU)

Langerhans cells histiocytosis is a dendritic cell disorder, result of clonal proliferation of this type of cells, morphologically rounded and immature immunophenotypically and functionally; associated with eosinophils, macrophages, lymphocytes and giant multinucleated cells at times. It can present monosystemic, affecting a single site or organ; or multisystemic disease when present in multiple organs or body systems. Medical literature and publications in which imaging is associated with the study and characterization of hematological diseases are scarce, even in the technological era. This paper presents a case of Langerhans cells histiocytosis that was followed imaging during 3 years with the subsequent support to diagnosis, treatment, monitoring and evaluation; demonstrating the usefulness of imaging as tool to achieve better patient management and as a principle of multidisciplinary medical care(AU)

A review on methods to estimate a CT from MRI data in the context of MRI-alone RT

Background: In recent years, Radiation Therapy (RT) has undergone many developments and provided progress in the field of cancer treatment. However, dose optimisation each treatment session puts the patient at risk of successive X-Ray exposure from Computed Tomography CT scans since this imaging modality is the reference for dose planning. Add to this difficulties related to contour propagation. Thus, approaches are focusing on the use of MRI as the only modality in RT. In this paper, we review methods for creating pseudo-CT images from MRI data for MRI-alone RT. Each class of methods is explained and underlying works are presented in detail with performance results. We discuss the advantages and limitations of each class. Methods: We classified recent works in deriving a pseudo-CT from MR images into four classes: segmentation-based, intensity-based, atlas-based and hybrid methods and the classification was based on considering the general technique applied. Results: Most research focused on the brain and the pelvic regions. The mean absolute error ranged from 80 to 137 HU and from 36.4 to 74 HU for the brain and pelvis, respectively. In addition, an interest in the Dixon MR sequence is increasing since it has the advantage of producing multiple contrast images with a single acquisition. Conclusion: Radiation therapy is emerging towards the generalisation of MRI-only RT thanks to the advances in techniques for generation of pseudo-CT images and the development of specialised MR sequences favouring bone visualisation. However, a benchmark needs to be established to set in common performance metrics to assess the quality of the generated pseudo-CT and judge on the efficiency of a certain method

Enhanced DNA damages of human prostate cancer cells induced by radiofrequency capacitive hyperthermia pre- and post X-rays: 6 MV versus 15 MV

Objective: This study aimed to determine the effect of 13.56 MHz radiofrequency [RF] capacitive hyperthermia [HT] on radiosensivity of human prostate cancer cells pre and post X-ray radiation treatment [RT]

Materials and Methods: In this experimental study, the human prostate cancer cell line DU145 was cultured as 300 micro m diameter spheroids. We divided the spheroids into group I: control, group II: HT at 43[degree]C for 30 minutes [HT], group III: 4 Gy irradiation with 6 MV X-ray [RT [6 MV]], group IV: 4 Gy irradiation with 15 MV X-ray [RT [15 MV]], group V: HT+RT [6 MV], group VI: HT+RT [15 MV], group VII: RT [6 MV]+HT, and group VIII: RT [15 MV]+HT. The alkaline comet assay was used to assess DNA damages in terms of tail moment [TM]. Thermal enhancement factor [TEF] was obtained for the different treatment combinations

Results: Mean TM increased with increasing photon energy. Group II had significantly greater TM compared to group I. Groups III and IV also had significantly higher TM compared to group I. Significant differences in TM existed between groups V, VII, and III [P<0.05]. We observed significant differences in TM between groups VI, VIII, and IV. TEF values demonstrated that enhanced response to radiation was more pronounced in group V compared to the other combined treatments

Conclusion: Our results suggest that HT applied before RT leads to higher radiosensivity compared to after RT. HT at 43[degree]C for 30 minutes added to 6 MV X-ray causes higher enhancement of radiation compared to 15 MV X-ray

Comparison of Electron and X-Ray Beams for Tumor Bed Boost Irradiation in Breast-Conserving Treatment / 한국유방암학회지

PURPOSE: This study aimed to compare the dosimetric profiles of electron beams (EB) and X-ray beams (XB) for boosting irradiation in breast cancer patients who underwent breast-conserving surgery and postoperative radiotherapy. METHODS: For 131 breast cancer patients who underwent breast-conserving surgery, we compared plans for EB and XB boost irradiation after whole-breast irradiation. The organs at risk (OAR) included the cardiac chambers, coronary arteries, ipsilateral lung, and skin. The conformity index (CI), inhomogeneity index (IHI), and dose-volume parameters for the planning target volume (PTV), and OAR were calculated. Postradiotherapy chest computed tomography scans were performed to detect radiation pneumonitis. RESULTS: XB plans showed a significantly better CI and IHI for the PTVs, compared to the EB plans. Regarding OAR sparing, the XB reduced the high-dose volume at the expense of an increased low-dose volume. In 33 patients whose radiation fields included nipples, IHI was higher in the EB plans, whereas the presence of a nipple in the radiation field did not interfere with the XB. EB-treated patients developed more subclinical radiation pneumonitis. CONCLUSION: XB plans were superior to EB plans in terms of PTV coverage (homogeneity and conformity) and high-dose volume sparing in OAR when used as boost irradiation after breast-conserving surgery. A disadvantage of the XB plan was an increased low-dose volume in the OAR, but this was offset by the increased electron energy. Consequently, tailored plans with either XB or EB are necessary to adapt to patient anatomic variance and tumor bed geometric properties.

Anti-tumor effect of pEgr-interferon-gamma-endostatin gene-radiotherapy in mice bearing Lewis lung carcinoma and its mechanism / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Gene-radiotherapy, the combination of gene therapy and radiation therapy, is a new paradigm for cancer treatment. To enhance anti-tumor effect of gene-radiotherapy, in this study we construct a radiation-inducible dual-gene co-expression vector pEgr-interferon (IFN)-gamma-endostatin and studied the anti-tumor effect of pEgr-IFN-gamma-endostatin gene-radiotherapy in mice bearing Lewis lung carcinoma and its mechanism.</p><p><b>METHODS</b>Gene recombinant technique was used to construct dual-gene co-expression plasmid pEgr-IFN-gamma-endostatin, and single-gene expression plasmid pEgr-IFN-gamma and pEgr-endostatin. The plasmids packed by liposome were injected locally into the tumors of the mice, and the tumors were irradiated with 5 Gy X-ray 36 hours later. The tumor growth rate at different time and mean survival period of the mice were observed. Cytotoxic activity of splenic cytotoxic T-lymphocyte (CTL), natural killer (NK) cell and tumor necrosis factor (TNF)-alpha secretion activity of peritoneal macrophages of the mice in various groups were evaluated 15 days after irradiation. The intratumor micro-vessel density was evaluated by immunohistochemical staining 10 days after irradiation.</p><p><b>RESULTS</b>The tumor growth rate of the mice in dual-gene-radiotherapy group was significantly lower than those in control group, 5 Gy group and single-gene-radiotherapy group at different time after gene-radiotherapy, and the mean survival period of which was longer. Cytotoxic activity of splenic CTL, NK and TNF-alpha secretion activity of peritoneal macrophages of the mice in dual-gene-radiotherapy group were significantly higher than those in control group, 5 Gy X-ray irradiation group and pEgr-endostatin gene-radiotherapy group 15 days after irradiation. The intratumor micro-vessel density of the mice in dual-gene-radiotherapy group was significantly lower than those in control group, 5 Gy X-ray irradiation group and pEgr-IFN-gammagene-radiotherapy group.</p><p><b>CONCLUSION</b>The anti-tumor effect of dual-gene-radiotherapy was significantly better than that of single-gene-radiotherapy by combining the enhancement of anti-tumor immunologic function induced by IFN-gamma with the anti-angiogenesis function of endostatin.</p>

Aplicação de metodologia dosimétrica de feixes terapêuticos de raios X com sistema Tandem / Application of a dosimetric methodology of therapeutic X-ray beams with a Tandem system

Um sistema Tandem, constituído por um par de câmaras de ionização comerciais (uma cilíndrica e uma de placas paralelas), foi estabelecido para aplicação em instituição hospitalar, em substituição ao procedimento convencional de determinação de camadas semi-redutoras utilizando-se absorvedores. Os resultados obtidos mostram a possibilidade de utilização deste sistema em procedimentos de dosimetria para os feixes de ortovoltagem utilizados em radioterapia, como complemento de um programa de controle de qualidade.

A Case of Multiple Basal Cell Carcinomas

The multifactorial etiology of BCC(basal cell carcinoma) are incompletely understood, including factors leading to multiple lesions in some patients. Cases of multiple BCCs reported in the literature have been associated with UV irradiation, inorganic arsenic poisoning, X-ray therapy, hematologic malignancy and several genodermatoses such as nevoid BCC syndrome, albinism, xeroderma pigmentosum. Multiple BCCs presented on the sun-protected areas, lacking predisposing risk factors which have been known, is rare skin condition. However, it suggests that there may be an unknown genetic susceptibility to the development of multiple BCCs. We report a rare case of multiple BCCs, which had developed only on the sun-protected areas in 64-year-old man, without any known predisposing causes.

Câncer do lábio inferior (tratamento e reparação pelo método de Krause) / Cancer of lower lip: Repair and treatment by the Krause's technique

Os autores apresentam alguns casos de perda de substância do lábio inferior por câncer e reparados pela técnica de Krause. Fazem previamente um estudo sumário dos carcinomas cutâneos e da sua distribuição anatômica segundo os tipos mais freqüentes (baso e espinocelulares) bem como da sua incidência racial. Apontam os dois tipos princiapais de tratamento: o cirúrgico e o radioativo (roentgenterapia e radiumterapia). Referem-se à lei radioterápica dos raio x de Bergonié-Tribondeau intimemente relacionadacom o grau de imaturidade das células tumorais. Realçam alguns princípios que devem ser respeitados no tratamento cirúrgico dos tumores cutâneos. Ressaltam a importância da reparação precoce da ferida cirúrgica reultante da exérese tumoral

Aspectos biológicos y médicos básicos sobre las radiaciones ionizantes / Basic medical and biological aspects of ionizing radiation

Las radiaciones tienen gran utilidad en medicina, Sin embargo, existen fuentes radiactivas (como las industriales) que pueden provocar exposiciones accidentales a radiaciones ionizantes que a su vez pueden repercutir en el organismo. En este trabajo se hace una revisión sobre aspectos básicos que los médicos de cualquier especialidad (especialmente aquellos que laboran en instituciones hospitalarias) deberían conocer y poder reconocer

Tortícolis congénita / Congenital torticolis

La tortícolis congénita (TC) es un espasmo o contractura unilateral del músculo esternocleidomastoideo, que se observa durante los primeros días de la vida del recién nacido y que produce una deformidad del cuello. El tratamiento consiste en la aplicación de calor, el cual puede ser local mediante compresas humedas calientes o profunda, mediante ultrasonido. En vista de que no existen estudios concluyentes a favor de uno de los dos, se plantea el presente ensayo clínico controlado. Se formaron dos grupos, uno para cada tipo de tratamiento, asignándose al azar los pacientes a cada uno de ellos. Cada grupo estuvo formado por 13 pacientes con edades comprendidas entre dos meses y un año. El tratamiento duró tres meses. Se compararon los arcos de movilidad del cuello antes y después del tratamiento, así como el tiempo transcurrido para su recuperación. No se encontraron diferencias significativas en ninguno de los aspectos estudiados al inicio del estudio, excepto en la flexión inicial. Sin embargo, ambos grupos se recuperaron al 100 por ciento en sus arcos de movilidad. Al comparar el tiempo de tratamiento, se encontraron diferencias significativas a favor del grupo que recibió ultrasonido. Este solo aspecto hace que éste sea el tratamiento de elección

Effect of X-radiation on the morphogenesis and histogenesis of the developing retina of the chick embryo

Morphological and histological studies were done on the retina of 10, 12 and 15 days chick embryos which were exposed to X-irradiation [1000 R at 200 k.v.] 48 hours after incubation. Retardation of growth of the retina was observed in 10 and 12 days treated chick embryos as evidenced by reduction of the size of the retina associated with disappearance of some layers of the retina. The retina of irradiated embryos showed signs of incomplete regeneration when these embryos were examined on the 15th day of incubation

Kaposi's Sarcoma: Report of a Case / 대한피부과학회지

A 24 year-old Korean male, has had an eruption on the Lt. foot for 3 years. The lesion consists of single large macule of reddish purplish brown coloration scattered over the great toe, dorsum and inner part of the Lt. foot. Recently, there is no new lesions and lymphadenopathy on any part of the body. Laboratory tests were all negative, including serology. X-ray findings of the chest and Lt. foot showed normal limits but, angiographic findings which was performed under the local anesthesia through the femoral artery showed the arterio-venous plexus and markedly increased vascularity on the inner side of Lt foot area. Biopsy of a macule on the inner part of the Lt. foot was confirmed as Kaposi's sarcoma. X-ray therapy (100Kv at 50cm distance with 2 mm of AL. filter) was directed to the involved sites daily for 6 days to a total of 1,800 roentogens, after lesion was progressively improved day by day.

A Case of the Primary Malignant Melanoma in Conjunctiva

Malignant melanoma is considered as one of the tumor originated from precancerous melanosis and predilected in the iris and choroid. The Authors experienced a case of malignant melanoma affecting the upper palpebral conjunctiva in 39 year old female. The tumor mass was excised radically and followed by X-Ray therapy. Slight opacities of lens body is developed after X-ray irradiation.