Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Tumori ; 109(6): 570-575, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37688419

RESUMEN

This study quantified the incidental dose to the first axillary level (L1) in locoregional treatment plan for breast cancer. Eighteen radiotherapy centres contoured L1-L4 on three different patients (P1,2,3), created the L2-L4 planning target volume (single centre planning target volume, SC-PTV) and elaborated a locoregional treatment plan. The L2-L4 gold standard clinical target volume (CTV) along with the gold standard L1 contour (GS-L1) were created by an expert consensus. The SC-PTV was then replaced by the GS-PTV and the incidental dose to GS-L1 was measured. Dosimetric data were analysed with Kruskal-Wallis test. Plans were intensity modulated radiotherapy (IMRT)-based. P3 with 90° arm setup had statistically significant higher L1 dose across the board than P1 and P2, with the mean dose (Dmean) reaching clinical significance. Dmean of P1 and P2 was consistent with the literature (77.4% and 74.7%, respectively). The incidental dose depended mostly on L1 proportion included in the breast fields, underlining the importance of the setup, even in case of IMRT.


Asunto(s)
Neoplasias de la Mama , Radioterapia de Intensidad Modulada , Humanos , Femenino , Neoplasias de la Mama/radioterapia , Planificación de la Radioterapia Asistida por Computador , Dosificación Radioterapéutica , Variaciones Dependientes del Observador , Mama
2.
Life (Basel) ; 13(3)2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36983949

RESUMEN

Primary mucosal melanoma (PMM) and pancreatic ductal adenocarcinoma (PDAC) are two aggressive malignancies, characterized by intrinsic radio-chemoresistance and neurotropism, a histological feature resulting in frequent perineural invasion (PNI), supported by neurotrophic factors secreted in the tumour microenvironment (TME), such as neurotrophin-3 (NT-3). Carbon-ion radiotherapy (CIRT) could represent an effective option in unresectable PMM and PDAC. Only a few data about the effects of CIRT on PNI in relation to NT-3 are available in the literature, despite the numerous pieces of evidence revealing the peculiar effects of this type of radiation on tumour cell migration. This in vitro study investigated for the first time the response of PMM and PDAC cells to NT-3 and evaluated the effects of conventional photon beam radiotherapy (XRT) and CIRT on cell viability, proliferation, and migration. Our results demonstrated the greater capacity of C-ions to generally decrease cell viability, proliferation, and migration, while the addition of NT-3 after both types of irradiation determined an increase in these features, maintaining a dose-dependent trend and acting more effectively as a chemoattractant than inductor in the case of migration.

3.
Int J Mol Sci ; 24(3)2023 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-36769302

RESUMEN

Colorectal cancer (CRC) is the most prominent form of colon cancer for both incidence (38.7 per 100,000 people) and mortality (13.9 per 100,000 people). CRC's poor response to standard therapies is linked to its high heterogeneity and complex genetic background. Dysregulation or depletion of the tumor suppressor p53 is involved in CRC transformation and its capability to escape therapy, with p53null cancer subtypes known, in fact, to have a poor prognosis. In such a context, new therapeutic approaches aimed at reducing CRC proliferation must be investigated. In clinical practice, CRC chemotherapy is often combined with radiation therapy with the aim of blocking the expansion of the tumor mass or removing residual cancer cells, though contemporary targeting of amino acid metabolism has not yet been explored. In the present study, we used the p53null Caco-2 model cell line to evaluate the effect of a possible combination of radiation and L-Asparaginase (L-ASNase), a protein drug that blocks cancer proliferation by impairing asparagine and glutamine extracellular supply. When L-ASNase was administered immediately after IR, we observed a reduced proliferative capability, a delay in DNA-damage response and a reduced capability to adhere and migrate. Our data suggest that a correctly timed combination of X-rays and L-ASNase treatment could represent an advantage in CRC therapy.


Asunto(s)
Neoplasias del Colon , Neoplasias Colorrectales , Humanos , Asparagina/metabolismo , Glutamina/metabolismo , Células CACO-2 , Proteína p53 Supresora de Tumor/genética , Asparaginasa/metabolismo , Línea Celular Tumoral , Radiación Ionizante , Neoplasias Colorrectales/genética
4.
Asian Pac J Allergy Immunol ; 41(1): 53-59, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34717523

RESUMEN

BACKGROUND: Alexithymia is among psychological factors reported to interfere with asthma management. Severe allergic asthma (SAA) is characterized by uncontrolled asthma despite maximal standard pharmacological treatment which can benefit from an add-on treatment with Omalizumab, an anti-IgE monoclonal antibody. OBJECTIVE: To evaluate if alexithymia influences the efficacy of omalizumab in SAA. METHODS: The total alexithymia score 20 (TAS 20) questionnaire allowed to detect alexithymia. SAA was monitored recording number of exacerbations, asthma control test (ACT) and asthma quality of life questionnaire (AQLQ) scores, as well as forced expiratory volumes in 1 second % (FEV1%) levels before starting omalizumab, 1 and 2 years after. RESULTS: The study was conducted on 18 patients; Group 1, TAS 20 ≥ 61, was of 2 males and 4 females with SAA and alexithymia, while Group 2 , TAS 20 ≤ 51, was of 8 males and 4 females, without alexithymia. Group 1 had a statistically significant decrease in asthma exacerbations "p = 0.004", while ACT "p = 0.008" and AQLQ scores statistically increased. FEV1 values increased but not statistically significantly. Group 2 had a highly statistically significant decrease in the number of exacerbations and a highly statistically significant increase of ACT "p < 0.0001", FEV1 "p = 0.008" and AQLQ scores. CONCLUSIONS: Regardless the presence or not of alexithymia, all patients with SAA obtained a marked improvement after starting treatment with omalizumab. Therefore alexithymia does not seem to influence the treatment outcome of omalizumab.


Asunto(s)
Asma , Omalizumab , Femenino , Masculino , Humanos , Omalizumab/uso terapéutico , Síntomas Afectivos/tratamiento farmacológico , Síntomas Afectivos/etiología , Calidad de Vida , Asma/tratamiento farmacológico , Resultado del Tratamiento , Inmunosupresores
5.
Eur J Endocrinol ; 187(6): 823-845, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36165745

RESUMEN

Objective: Acromegaly is associated with somatic disfigurements which impair self-perception of well-being and quality of life. Nowadays, limited data are available on the interplay between hormonal excess and psychological discomfort. The study aimed at investigating the psychological profile, sleep quality, sexual function, cognitive functions, and quality of life in patients with acromegaly. Methods: In 223 acromegaly patients from 5 referral centres, global psychological profile, sleep quality, sexual function, cognitive function, and quality of life were investigated. Results: Depression was found in ~30% of patients, and anxiety in two-thirds, together with severe discomfort in body image mainly in women. Obstructive sleep apnoea syndrome risk and sleep disorders were found in >50% of patients and daily sleepiness in ~20%. Sexual dysfunction was reported in most of the patients, with the most severe impairment in women. Cognitive functions were compromised in ~10% of cases. Disease duration and patient's age and gender were the main determinants of these psychopathological conditions. Depression (P = 0.047), somatic-affective mood lowering (P = 0.021), state (P < 0.001) and trait (P = 0.013) anxiety, and body image distortion in body uneasiness test A (P < 0.001) and B (P = 0.006) were significantly worsened in patients <45 years and slightly worsened in those with disease duration less than 2 years. Male (P < 0.001) and female (P < 0.001) sexual function scores were significantly worsened in patients aged >64 years and slightly worsened in those with disease duration for more than 10 years, particularly in presence of cardiometabolic and respiratory complications. Cognitive symptoms were slightly worsened in older patients and in those with long disease duration. Conclusions: Acromegaly is associated with a relevant impairment of psychological profile persisting despite remission and long-term medical treatment.


Asunto(s)
Acromegalia , Calidad de Vida , Humanos , Femenino , Masculino , Anciano , Estudios Transversales , Calidad del Sueño , Acromegalia/terapia , Cognición
6.
Br J Radiol ; 94(1123): 20201177, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33882239

RESUMEN

OBJECTIVES: To determine interobserver variability in axillary nodal contouring in breast cancer (BC) radiotherapy (RT) by comparing the clinical target volume of participating single centres (SC-CTV) with a gold-standard CTV (GS-CTV). METHODS: The GS-CTV of three patients (P1, P2, P3) with increasing complexity was created in DICOM format from the median contour of axillary CTVs drawn by BC experts, validated using the simultaneous truth and performance-level estimation and peer-reviewed. GS-CTVs were compared with the correspondent SC-CTVs drawn by radiation oncologists, using validated metrics and a total score (TS) integrating all of them. RESULTS: Eighteen RT centres participated in the study. Comparative analyses revealed that, on average, the SC-CTVs were smaller than GS-CTV for P1 and P2 (by -29.25% and -27.83%, respectively) and larger for P3 (by +12.53%). The mean Jaccard index was greater for P1 and P2 compared to P3, but the overlap extent value was around 0.50 or less. Regarding nodal levels, L4 showed the highest concordance with the GS. In the intra-patient comparison, L2 and L3 achieved lower TS than L4. Nodal levels showed discrepancy with GS, which was not statistically significant for P1, and negligible for P2, while P3 had the worst agreement. DICE similarity coefficient did not exceed the minimum threshold for agreement of 0.70 in all the measurements. CONCLUSIONS: Substantial differences were observed between SC- and GS-CTV, especially for P3 with altered arm setup. L2 and L3 were the most critical levels. The study highlighted these key points to address. ADVANCES IN KNOWLEDGE: The present study compares, by means of validated geometric indexes, manual segmentations of axillary lymph nodes in breast cancer from different observers and different institutions made on radiotherapy planning CT images. Assessing such variability is of paramount importance, as geometric uncertainties might lead to incorrect dosimetry and compromise oncological outcome.


Asunto(s)
Axila , Neoplasias de la Mama/radioterapia , Metástasis Linfática/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Neoplasias de la Mama/patología , Femenino , Humanos , Italia , Metástasis Linfática/patología , Variaciones Dependientes del Observador
7.
Front Immunol ; 11: 1077, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32655551

RESUMEN

In vitro co-culture models between tumor cells and peripheral blood mononuclear cells (PBMCs) allow studying the interplay between these cell populations, potentially gaining insight into the in vivo response of the immune system to the presence of the tumor, as well as to possible other agents as radiation used for therapeutic purposes. However, great care is needed in the experimental optimization of models and choice of conditions, as some setups might offer a limited possibility to capture subtle immune perturbations. A co-culture model of PBMCs from healthy donors and colorectal adenocarcinoma Caco-2 cells was successfully adopted in a previous work to measure effects on Caco-2 and modulation of signaling when these latter are irradiated. We here tested if the same experimental setting allows to measure perturbations to the main PBMC subsets: we performed immunophenotyping by means of flow cytometry and quantified helper and cytotoxic T cells, NK cells, and B cells, when PBMCs are cultured alone (control), in presence of non-irradiated Caco-2 cells or when these latter are exposed to a 10 Gy X-ray dose from a conventional radiotherapy accelerator. To measure a baseline response in all experimental conditions, PBMCs were not further stimulated, but only followed in their time-evolution up to 72 h post-irradiation of Caco-2 and assembly of the co-culture. In this time interval PBMCs maintain a high viability (measured via the MTT assay). Caco-2 viability (MTT) is slightly affected by the presence of PBMCs and by the high radiation dose, confirming their radioresistance. Immunophenotyping results indicate a large inter-individual variability for different population subsets already at the control level. We analyzed relative population changes and we detected only a small but significant perturbation to cytotoxic T cells. We conclude that this model, as it is, is not adequate for the measurements of subtler immune perturbations (if any, not washed-out by inter-individual differences). For this purpose, the model needs to be modified and further optimized e.g., including a pre-treatment strategy for PBMCs. We also performed a pooled analysis of all experimental observations with principal component analysis, suggesting the potential of this tool to identify subpopulations of similarly-responding donors.


Asunto(s)
Adenocarcinoma/inmunología , Adenocarcinoma/radioterapia , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/radioterapia , Leucocitos Mononucleares/inmunología , Adenocarcinoma/patología , Células CACO-2 , Supervivencia Celular/inmunología , Supervivencia Celular/efectos de la radiación , Técnicas de Cocultivo/métodos , Neoplasias Colorrectales/patología , Humanos , Inmunofenotipificación , Leucocitos Mononucleares/clasificación , Modelos Inmunológicos , Análisis de Componente Principal , Dosificación Radioterapéutica , Linfocitos T Citotóxicos/inmunología
8.
J Appl Clin Med Phys ; 19(4): 35-43, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29740971

RESUMEN

The aim of this study was to investigate the use of 3D optical localization of multiple surface control points for deep inspiration breath-hold (DIBH) guidance in left-breast radiotherapy treatments. Ten left-breast cancer patients underwent whole-breast DIBH radiotherapy controlled by the Real-time Position Management (RPM) system. The reproducibility of the tumor bed (i.e., target) was assessed by the position of implanted clips, acquired through in-room kV imaging. Six to eight passive fiducials were positioned on the patients' thoraco-abdominal surface and localized intrafractionally by means of an infrared 3D optical tracking system. The point-based registration between treatment and planning fiducials coordinates was applied to estimate the interfraction variations in patients' breathing baseline and to improve target reproducibility. The RPM-based DIBH control resulted in a 3D error in target reproducibility of 5.8 ± 3.4 mm (median value ± interquartile range) across all patients. The reproducibility errors proved correlated with the interfraction baseline variations, which reached 7.7 mm for the single patient. The contribution of surface fiducials registration allowed a statistically significant reduction (p < 0.05) in target localization errors, measuring 3.4 ± 1.7 mm in 3D. The 3D optical monitoring of multiple surface control points may help to optimize the use of the RPM system for improving target reproducibility in left-breast DIBH irradiation, providing insights on breathing baseline variations and increasing the robustness of external surrogates for DIBH guidance.


Asunto(s)
Mama , Neoplasias de la Mama , Contencion de la Respiración , Corazón , Humanos , Mastectomía Segmentaria , Planificación de la Radioterapia Asistida por Computador , Reproducibilidad de los Resultados , Tomografía Computarizada por Rayos X , Neoplasias de Mama Unilaterales
9.
Breast ; 39: 123-130, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29674010

RESUMEN

BACKGROUND: Intraoperative radiotherapy (IORT) could be not-inferior to external beam radiotherapy (EBRT) in selected patients, but toxicities, self-perception of body image, quality of life, and resumption of work or daily activities have been poorly explored. The aim of the present study was to compare these outcomes between EBRT, IORT full-dose (IORT-f) and IORT boost (IORT-b). METHODS: 443 consecutive patients, candidates for breast-conserving surgery, were included: EBRT was performed in 220 patients (49.7%), IORT-f in 140 patients (31.6%), and IORT-b in 83 patients (18.7%). Radiotherapy-related toxicities were registered. Patients were evaluated at 6 months for Body Image after Breast Cancer Questionnaire (BIBCQ) to assess possible changes in self-perception of body image and limitations. A second questionnaire explored the impact of EBRT, IORT-f and IORT-b on resumption of work and normal daily activities. RESULTS: EBRT had a higher risk of breast fibrosis and retraction (OR 3.58, 95% CI 1.024-12.526, p = 0.046) and breast edema (OR 6, 95% CI 2.077-17.335, p = 0.001) compared to IORT-f, but a lower risk of seroma compared to IORT-b (OR 0.36, 95% CI 0.166-0.785, p = 0.01). The BIBCQ scores showed a better outcome in arm concerns with IORT-f (-3.3) vs. IORT-b (-1.3, p = 0.002) and EBRT (-1.7, p = 0.006), although biased by the lower rate in axillary dissections. Return to daily activities occurred after 70.6 days with EBRT vs. 41 days with IORT-f (p < 0.0001) and 53.3 days with IORT-b (p = 0.07), without any effect of age or axillary dissection. CONCLUSION: IORT could reduce adverse effects, allowing faster resumption of job and houseworks.


Asunto(s)
Neoplasias de la Mama/radioterapia , Cuidados Intraoperatorios/métodos , Mastectomía Segmentaria/métodos , Calidad de Vida , Reinserción al Trabajo , Anciano , Imagen Corporal/psicología , Neoplasias de la Mama/psicología , Neoplasias de la Mama/cirugía , Femenino , Humanos , Mastectomía Segmentaria/psicología , Persona de Mediana Edad , Periodo Posoperatorio , Dosificación Radioterapéutica , Radioterapia Adyuvante/métodos , Resultado del Tratamiento
10.
J Vis Exp ; (131)2018 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-29443050

RESUMEN

The protocol adopted in this work aims at unraveling how X-rays perturb the functioning of the intestinal barrier, focusing on the interplay between colorectal tumor cells and the immune system. Colorectal carcinoma is among the most common type of cancer, typically treated by surgery, chemotherapy, and radiotherapy. Advantages of radiotherapy in targeting the tumor are well known. However, even limited exposures of healthy tissues are of great concern, particularly regarding the effects on the intestinal barrier and the immune system. The adopted setup allows to study the interplay between two cell populations in a condition more similar to the physiological one, when compared to normal cell cultures. For this purpose, we resort to different techniques and we used an in vitro co-culture model, based on Caco-2 cells differentiated as a monolayer and PBMC, sharing the same culture medium. This protocol has been developed to focus on both macroscopic effects, i.e. cell viability and Trans-Epithelial Electrical Resistance (TEER), and, through western blot, molecular alterations, i.e. the activation of inflammatory pathway in immune cells and the tight junction protein expression in Caco-2 cells. Initial evaluation of radiation effects on Caco-2 cell viability was assessed via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Trypan blue assays, while TEER was measured at fixed time intervals through an ohmmeter specifically designed for co-culture systems. In this way, the effects due to radiation, the presence of Peripheral Blood Mononuclear Cells (PBMC), and eventually their synergistic effect, can be demonstrated. Through these complementary techniques, we observed a high radio-resistance of Caco-2 within the range of 2 - 10 Gy of X-rays and an increased Caco-2 monolayer permeability when PBMCs were added. In particular, PBMC presence was found to be associated with the variation in the tight junction scaffold proteins expression.


Asunto(s)
Células CACO-2/citología , Técnicas de Cocultivo/métodos , Leucocitos Mononucleares/citología , Células CACO-2/efectos de la radiación , Diferenciación Celular/efectos de la radiación , Humanos , Leucocitos Mononucleares/efectos de la radiación , Rayos X
11.
Maturitas ; 107: 92-96, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29169588

RESUMEN

OBJECTIVES: Gender identity disorder is defined as a strong and persistent cross-gender identification that is associated with a remarkable uneasiness of living in an incongruent gender (gender dysphoria). We performed a retrospective study on the hormonal and metabolic effects of cross-sex hormone therapy (CSHT) in a small cohort of transgender patients. STUDY DESIGN: Retrospective study. MEAN OUTCOME MEASURES: Hormonal and biochemical parameters at baseline (i.e. before commencement of CSHT) and while on CSHT in 32 patients (21 male to female [MtF], 11 female to male [FtM]) referred to our Endocrinology Unit for gender dysphoria between January 2012 and February 2017. RESULTS: Compared with baseline, in MtF patients systolic blood pressure, red cell count, hemoglobin, hematocrit and total testosterone decreased significantly, while 17-ß estradiol and SHBG increased significantly and trendwise significantly, respectively. In FtM patients, total testosterone, red cell count, hemoglobin, hematocrit, creatinine, É£-glutamyl transferase and alkaline phosphatase increased significantly, while fasting plasma glucose decreased trendwise significantly. In MtF patients 17-ß estradiol correlated positively with SHBG and alkaline phosphatase and negatively with total cholesterol and HDL-c, whereas total testosterone correlated positively with systolic blood pressure, red cell count and hematocrit, and negatively with SHBG. In FtM patients total testosterone correlated positively with creatinine and alkaline phosphatase, while 17-ß estradiol correlated positively with HDL-c. CONCLUSIONS: Our data are partly in line with other studies concerning the impact of CSHT on hormonal and metabolic parameters in transgender people. Metabolic changes appear, overall, to be modest, confirming the safety of CSHT.


Asunto(s)
Andrógenos/uso terapéutico , Estradiol/uso terapéutico , Estrógenos/uso terapéutico , Testosterona/uso terapéutico , Personas Transgénero , Adolescente , Adulto , Fosfatasa Alcalina/sangre , Andrógenos/sangre , Glucemia/análisis , Presión Sanguínea , Colesterol/sangre , Recuento de Eritrocitos , Estradiol/sangre , Estrógenos/sangre , Femenino , Disforia de Género , Hematócrito , Hemoglobinas , Humanos , Masculino , Estudios Retrospectivos , Globulina de Unión a Hormona Sexual/análisis , Testosterona/sangre , Adulto Joven , gamma-Glutamiltransferasa/sangre
12.
Community Ment Health J ; 52(5): 582-8, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26399518

RESUMEN

The aim of this study is to investigate the variables shown to be linked to serious suicide attempts. Cases requiring emergency admission to intensive care were collected from medical records of the University Hospital in Messina (Italy) for the years 2006-2010. 107 cases of serious attempted suicide were examined, 39 of which ended in the death of the patient. The results showed the following variables to be linked highly significantly (P < 0.01) and have good nominal association (V > 0.30) with a fatal suicidal attempt: the year of the attempt, deceased father, history of physical illness prior to hospitalization and method used to carry out the suicide attempt. These results confirm the severity and the multidisciplinary importance of this phenomenon.


Asunto(s)
Intento de Suicidio/prevención & control , Adolescente , Adulto , Anciano , Familia/psicología , Femenino , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Intento de Suicidio/psicología , Intento de Suicidio/estadística & datos numéricos , Adulto Joven
13.
Int J Adolesc Med Health ; 27(3): 311-7, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25720040

RESUMEN

BACKGROUND: This correlational study explored the psychosocial aspects related to eating behavior in different age samples of adolescents in treatment from 0 to 60 months at the Clinic of Orthodontics and Dentistry of Messina, Messina, Italy. The aim of the study was to investigate the relationship between psychosocial impact, levels of self-esteem, and the possible connection with eating habits of adolescents under orthodontic treatment. METHODS: Sixty-one adolescents, aged between 12 and 22 years (mean=15.6 ± 2.8) participated to the study. Each adolescents was interviewed with the Eating Attitudes Test, the Rosenberg Self Esteem Scale, and the Psychosocial Impact of Dental Aesthetics Questionnaire. RESULTS: Data did not show a direct connection between eating disorder and dental aesthetics, nevertheless, adolescents under orthodontic treatment, especially in the earliest phase of wearing braces, showed peculiar eating habits and underwent a higher psychological impact of dental aesthetics. Eating behaviors are strictly linked to global self-esteem. The processing of the results was made through the Student's t-test and using Pearson's correlation analysis. CONCLUSION: Increased knowledge of the psychological aspects involved in orthodontic treatment compliance may have positive effects in the relationship between adolescent patients and orthodontists. More attention should be paid to aspects that are often underestimated in clinical practice, thus, influencing the outcome of treatment and patient satisfaction, not only in terms of dental health, but also of mental health.


Asunto(s)
Conducta del Adolescente/psicología , Estética Dental/psicología , Conducta Alimentaria/psicología , Ortodoncia Correctiva/psicología , Adolescente , Niño , Clínicas Odontológicas , Femenino , Humanos , Entrevistas como Asunto , Italia , Masculino , Autoimagen , Distribución por Sexo , Percepción Social , Adulto Joven
14.
Phys Med Biol ; 60(4): 1565-82, 2015 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-25615399

RESUMEN

The aim of this study is the development and experimental testing of a tumor tracking method for particle radiation therapy, providing the daily respiratory dynamics of the patient's thoraco-abdominal anatomy as a function of an external surface surrogate combined with an a priori motion model. The proposed tracking approach is based on a patient-specific breathing motion model, estimated from the four-dimensional (4D) planning computed tomography (CT) through deformable image registration. The model is adapted to the interfraction baseline variations in the patient's anatomical configuration. The driving amplitude and phase parameters are obtained intrafractionally from a respiratory surrogate signal derived from the external surface displacement. The developed technique was assessed on a dataset of seven lung cancer patients, who underwent two repeated 4D CT scans. The first 4D CT was used to build the respiratory motion model, which was tested on the second scan. The geometric accuracy in localizing lung lesions, mediated over all breathing phases, ranged between 0.6 and 1.7 mm across all patients. Errors in tracking the surrounding organs at risk, such as lungs, trachea and esophagus, were lower than 1.3 mm on average. The median absolute variation in water equivalent path length (WEL) within the target volume did not exceed 1.9 mm-WEL for simulated particle beams. A significant improvement was achieved compared with error compensation based on standard rigid alignment. The present work can be regarded as a feasibility study for the potential extension of tumor tracking techniques in particle treatments. Differently from current tracking methods applied in conventional radiotherapy, the proposed approach allows for the dynamic localization of all anatomical structures scanned in the planning CT, thus providing complete information on density and WEL variations required for particle beam range adaptation.


Asunto(s)
Tomografía Computarizada Cuatridimensional/métodos , Radioterapia de Iones Pesados/métodos , Radioterapia Guiada por Imagen/métodos , Técnicas de Imagen Sincronizada Respiratorias/métodos , Simulación por Computador , Humanos , Movimiento (Física) , Respiración
16.
J Appl Clin Med Phys ; 15(1): 4494, 2014 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-24423845

RESUMEN

Deep inspiration breath hold (DIBH) in left-sided breast cancer radiotherapy treatments allows for a reduction in cardiac and pulmonary doses without compromising target coverage. The selection of the most appropriate technology for DIBH monitoring is a crucial issue. We evaluated the stability and reproducibility of DIBHs controlled by a spirometric device, by assessing the variability of the external surface position within a single DIBH (intra-DIBH) and between DIBHs performed in the same treatment session (intrafraction) or in different sessions (interfraction). The study included seven left-breast cancer patients treated with spirometer-based DIBH radiotherapy. Infrared optical tracking was used to record the 3D coordinates of seven to eleven passive markers placed on the patient's thoraco-abdominal surface during 29-43 DIBHs performed in six to eight treatment sessions. The obtained results showed displacements of the external surface between different sessions up to 6.3mm along a single direction, even at constant inspired volumes. The median value of the interfraction variability in the position of breast passive markers was 2.9 mm (range 1.9-4.8 mm) in the latero-lateral direction, 3.6 mm (range 2.2-4.6mm) in the antero-posterior direction, and 4.3mm (range 2.8-6.2 mm) in the cranio-caudal direction. There were no significant dose distribution variations for target and organs at risk with respect to the treatment plan, confirming the adequacy of the applied clinical margins (15 mm) to compensate for the measured setup uncertainties. This study demonstrates that spirometer-based control does not guarantee a stable and reproducible position of the external surface in left-breast DIBH radiotherapy, suggesting the need for more robust DIBH monitoring techniques when reduced margins and setup uncertainties are required for improving normal tissue sparing and decreasing cardiac and pulmonary toxicity.


Asunto(s)
Neoplasias de la Mama/radioterapia , Corazón/efectos de la radiación , Pulmón/efectos de la radiación , Traumatismos por Radiación/prevención & control , Monitoreo de Radiación , Respiración , Espirometría/métodos , Algoritmos , Simulación por Computador , Femenino , Humanos , Fantasmas de Imagen , Pronóstico , Dosificación Radioterapéutica , Radioterapia Adyuvante , Reproducibilidad de los Resultados , Tomografía Computarizada por Rayos X
17.
Radiat Prot Dosimetry ; 122(1-4): 116-20, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17166872

RESUMEN

The biophysical simulation code PARTRAC was extended by a module to handle ions heavier than alpha particles. Cross sections for ion-electron interactions were taken from He(++) ions of the same velocity and scaled by Z(eff(2))/4. Calculated linear energy transfer values, radial dose distributions and secondary electron spectra were found in agreement with experimental results. DNA damage due to irradiation of human fibroblast cells by several light ions from H to S was calculated for various energies complemented by 220 kV(p) X rays as reference radiation. With increasing linear energy transfer, the calculated total yield of double-strand breaks per dose showed saturation behaviour at about twice the value for reference radiation. When data analysis methods for experimental double-strand break yield determination were applied to the simulated DNA damage patterns, the two data sets were found in accord. The calculated patterns of DNA damage clusters were analysed on local and regional scale finding regional clusters in closer correlation to experimental cell inactivation data.


Asunto(s)
Cromatina/química , Cromatina/efectos de la radiación , Daño del ADN , ADN/química , ADN/efectos de la radiación , Modelos Químicos , Simulación por Computador , Relación Dosis-Respuesta en la Radiación , Iones , Transferencia Lineal de Energía , Modelos Moleculares , Dosis de Radiación , Radiación Ionizante
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA