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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.
Subject(s)
Animals , Rats , Radiation, Ionizing , X-Ray Therapy/adverse effects , Dental Pulp , HyalinABSTRACT
RESUMEN Introducción: en Cuba, en el 2018, fueron diagnosticados un total de 12 070 nuevos casos de cáncer de piel, de los cuales se estima que 11 587 corresponden a la variante no melanómica. La radioterapia con rayos x está considerada como la primera opción de tratamiento en muchos de estos casos. Recientemente, el sistema nacional de salud, adquirió cuatro equipos de la marca SENSUS SRT-100TM para el tratamiento del NMSC. Objetivo: desarrollar una metodología estandarizada para la caracterización dosimétrica de los equipos de radioterapia superficial con rayos X instalados en Cuba. Métodos: se caracterizaron cuatro equipos de radioterapia SENSUS SRT-100TM para cada una de sus calidades radiológicas, en términos de linealidad, estabilidad, capa hemirreductora, tasas de dosis de referencia, perfiles de dosis, factores de cono y porcentaje de dosis en profundidad. Se emplearon para ello, las recomendaciones de la AAPM TG-61 y el IAEA-TRS 398. Resultados: lo promedios de las HVLs (mm Al) y sus respectivos coeficientes de variación (CV) fueron de 5,526 - 5,2 %; 1,130 - 2,1 % y 2,007 - 2,1 % para 50,70 y 100 kV respectivamente. Los rendimientos presentaron poca variabilidad entre máquinas (CV < 3%) y fueron muy similares por los métodos "en agua" y "en aire" (discrepancia. < 0,5 %). Conclusiones: los equipos muestran una excelente estabilidad, y características dosimétricas muy similares entre ellos, lo cual permite establecer valores de referencia para eventuales auditorías externas y re-ajustes de los haces ulteriormente a los mantenimientos o reparaciones que impliquen al generador de rayos X.
ABSTRACT Introduction: in Cuba, in 2018, a total of 12 070 new cases of skin cancer were diagnosed, from which it is estimated that 11 587 correspond to the non-melanoma type. Radiation therapy with X-rays is considered the first-line treatment in many of these cases. Recently, the national healthcare system acquired four SENSUS SRT-100TM units for treating Non-Melanoma Skin Cancer (NMSC). Objective: to develop a standardized methodology for the dosimetric characterization of the equipments of surface radiotherapy with X-rays installed in Cuba. Methods: four SENSUS SRT-100TM radiotherapy equipments were characterized for each of their radiological qualities, in terms of linearity, stability, hemi-reductive layer, reference dose rates, dose profiles, cone factors and percentage of dose in depth. The recommendations of the AAPM TG-61 and the IAEA-TRS 398 were applied for this purpose. Results: the averages of HVLs (mm Al) and their respective coefficients of variation (CV) were 5,526 - 5,2 %; 1,130 - 2,1 % and 2,007 - 2,1 % for 50, 70 and 100 kV respectively. The yields presented little variability between machines (CV < 3%) and were very similar by the methods "in water" and "in air" (discrepancy < 0,5 %). Conclusions: the equipments show excellent stability and very similar dosimetric characteristics among them, which allows establishing reference values for eventual external audits and beam readjustments after the maintenance or repairs involving the X-ray generator.
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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.
Subject(s)
Humans , Breast Neoplasms , Coronary Vessels , Electrons , Lung , Mastectomy, Segmental , Nipples , Organs at Risk , Radiotherapy, Adjuvant , Skin , Thorax , X-Ray TherapyABSTRACT
Objective: To investigate the mechanism by which X-irradiation inhibited the invasion and metastasis of human lung adenocarcinoma cell line. Methods: A549 cells were irradiated with varying doses of 6 MV X-ray. Soft agar colony formation assay was employed to evaluate the effects of X-irradiation on the proliferation of A549 cells. RT-PCR and Western blotting were performed to analyze the protein and mRNA expression levels of E-cadherin and β-catenin. The invasion of A549 cells was evaluated by the Transwell chamber migration assay. Results: X-irradiation could inhibit the proliferation of A549 cells in a dose-dependent manner. The protein and mRNA expression levels of E-cadherin in A549 cells were higher than those in the control group (P 0.05). And the cell invasion capability was decreased with the increase in the dose of irradiation (P <0.05). Conclusion: X-irradiation up-regulated the expression of E-cadherin and β-catenin in A549 cells, which enhanced the intracellular adhesion and suppressed the invasion capability. That may be the mechanism for the inhibitory effects of X-irradiation on metastasis of human lung adenocarcinoma cell line.
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Objective To observe the effect of cures of keloids by operation and closely following X-ray therapy. Methods X-ray therapy was taken in no more than 24 hours after the keloids removing operations on 63 subjects, partly irradiating incision with 100～140kv X-ray,which was continued in the next three days,once for each day,till the total amount reached DT 1600～2000cGY. Results All postoperative incision healed in one-stage,all cases were followed up for 6～12 months, the new hyperplastic scar didn' t appeare on the incision of 57 subjects, while this happened on those of the other six with some improvement after operation than before operation. Rate of healing reached 90. 5% .Conclusion Cure of keloid by operation and closely following X-ray therapy can reach low recurrence and aesthetic effection,and it is worth popularizing in the clinic.
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Objective To investigate the therapeutic indications,dosage and prognosis of dermato-mucous membrane heamangioma(DMMH)in infants using low-dose superficial X-ray irradiation.Methods The patients were treated with a superficial X-ray machine(DERMOPAN typeⅡ)at voltages of29kV,43kV and50kV according to the depth and position of angioma,one or two times per week,1~2Gy per time,with the average total doses of5~10Gy and the maximal dose of20Gy.Results In a total of267patients,230cured,24markedly improved,10improved,and3failed.The cure rate was86.14%,and the total improve-ment rate was95.13%.Conclusion Treatment of DMMH with low-dose superfical X-ray is simple,conve-nient,safe,painless and cheap.The method has a high cure rate and is well accepted by the chlidren and their parents.
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Three hundred cases of abdominal emergencies due to ascaris infection because of the presence of ascaris in the vomitus and or stools, severe abdominal pain with tenderness, palpable masses and positive signs in the roentgenograms were studied. Of the cases presented only 3 were operated on mainly on the basis of clinical and radiologic findings of complete obstruction. Conservative management is still our treatment of choice. Roentgen examination is considered as the most helpful diagnostic procedure. (Summary)
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Objective To investigate the effective mechanism, time and rational dose of radiotherapy of epileptic rat. Methods To make rat model of epilepsy, and give 0, 24,12 or 6Gy X ray irradiation, and then detect the amino-acid contents in frontal lobe of those rats in 1 hour, 24 hours or 1 week after radiotherapy. Results Glu and GABA are the key amino-acids in radio effection. After 12Gy or 24Gy irradiation there were low Glu, high GABA and low Glu/GABA in frontal lobe of rat. After 1h, 24h and 1 week irradiation, the contents of GABA raised up while the ratio of Glu/GABA declined with a remarkable decline at 24h. Conclusions Radiotherapy to epileptic rat may set off a rapid and enduring change of GABA and Glu transmitters, and 12Gy may be the rational radio dose for epileptic rat.