Sketched reference databases for genome-based taxonomy and comparative genomics.

The analysis of curated genomic, metagenomic and proteomic data is of paramount importance in the fields of biology, medicine, education, and bioinformatics. Although this type of data is usually hosted in raw format on free international repositories, the full access requires lots of computing power and large storage disk space for the domestic user. The purpose of the study is to offer a comprehensive set of microbial genomic and proteomic reference databases in an accessible and easy-to-use form to the scientific community and demonstrate its advantages and usefulness. Also, we present a case study on the applicability of the sketched data, for the determination of overall genomic coherence between two members of the Brucellacea family, which suggests they belong to the same genomospecies that remain as discrete ecotypes. A representative set of genomes, proteomes (from type material), and metagenomes were directly collected from the NCBI Assembly database and Genome Taxonomy Database (GTDB), associated with the major groups of Bacteria, Archaea, Virus, and Fungi. Sketched databases were subsequently created and stored on handy reduced representations by using the MinHash algorithm implemented in Mash software. The obtained dataset contains more than 133 GB of space disk reduced to 883.25 MB and represents 125,110 genomics/proteomic records from eight informative contexts, which have been prefiltered to make them accessible, usable, and user-friendly with limited computational resources. Potential uses of these sketched databases are discussed, including but not limited to microbial species delimitation, estimation of genomic distances and genomic novelties, paired comparisons between proteomes, genomes, and metagenomes; phylogenetic neighbor's exploration and selection, among others.

Diabetes gestacional. Diagnóstico y tratamiento en el primer nivel de atención / Gestational diabetes mellitus. Diagnosis and treatment in the first level of care

Resumen La diabetes mellitus gestacional se define como cualquier intolerancia a los carbohidratos diagnosticada durante el embarazo. La prevalencia de esta enfermedad es aproximadamente de 2 a 5% de los embarazos normales y depende de la prevalencia de la población a la diabetes mellitus tipo 2. Se asocia con resultados adversos para la madre, el feto, el recién nacido, el niño y los hijos adultos de madre diabética. La detección de la diabetes mellitus gestacional está en el cribado, realizado como sea necesario a través de medidas de diagnóstico. La poroyección puede ser selectiva, basada en la estratificación del riesgo o ser universal. Las pruebas oportunas permiten al médico obstetra evaluar la tolerancia de la glucosa relacionada con el estado resistente a la insulina del embarazo y permite iniciar el tratamiento antes de que ocurra el crecimiento fetal excesivo. Una vez que se estableció el diagnóstico de diabetes mellitus gestacional se justifica la estrecha vigilancia perinatal. El objetivo del tratamiento es reducir la morbilidad y mortalidad materno-fetal relacionadas con la enfermedad. Los valores exactos necesarios de glucosa todavía no están demostrados de manera absoluta. La decisión de inducir el parto y cuándo depende de la edad gestacional, el peso fetal estimado, el control de la glucemia materna y la puntuación obispo. Se necesitan investigaciones futuras en materia de prevención de diabetes mellitus gestacional, los objetivos del tratamiento y eficacia de las intervenciones, las directrices en la atención del embarazo y la prevención de las secuelas metabólicas a largo plazo para el niño y la madre.

Abstract Gestational diabetes mellitus is defined as any carbohydrate intolerance first diagnosed during pregnancy. The prevalence of gestational diabetes mellitus is about 2-5% of normal pregnancies and depends of the prevalence of same population to diabetes mellitus type 2. It is associated with adverse outcome for the mother, the fetus, neonate, child and adult offspring of the diabetic mother. Detection of gestational diabetes mellitus lies on screening, followed as necessary by diagnostic measures. Screening can either be selective, based upon risk stratification or universal. Timely testing enables the obstetrician to assess glucose tolerance in the presence of the insulin-resistant state of pregnancy and permits treatment to begin before excessive fetal growth has occurred. Once a diagnosis of gestational diabetes mellitus was made close perinatal surveillance is warranted. The goal of treatment is reducing fetal-maternal morbidity and mortality related with gestational diabetes mellitus. The exact glucose values needed are still not absolutely proved. The decision whether and when to induce delivery depends on gestational age, estimated fetal weight, maternal glycemic control and bishop score. Future research is needed regarding prevention of gestational diabetes mellitus, treatment goals and effectiveness of interventions, guidelines for pregnancy care and prevention of long term metabolic sequel for both the infant and the mother.

Effectiveness and toxicity of helical tomotherapy for patients with locally recurrent nasopharyngeal carcinoma

Purpose. We assessed therapeutic outcomes of reirradiation with helical tomotherapy (HT) for locoregional recurrent nasopharyngeal carcinoma (LRNPC) patients. Methods and materials. Treatment outcomes were evaluated retrospectively in 17 consecutive LRNPC patients receiving HT between 2006 and 2012. Median age was 57 years and most patients (n = 13) were male. Simultaneous systemic therapy was applied in 5 patients. Initial treatment covered the gross tumor volume with a median dose of 70 Gy (60–81.6 Gy). Reirradiation was confined to the local relapse region with a median dose of 63 Gy (50–70.2 Gy), resulting in a median cumulative dose of 134 Gy (122–148.2 Gy). The median time interval between initial and subsequent treatment was 42 months (11–126). Results. The median follow-up for the entire cohort was 23 and 35 months for survivors. Three patients (18 %) developed both local and distant recurrences and only one patient (6 %) suffered from isolated local recurrence. Two-year actuarial DFS and LC rates were 74 and 82 %, respectively. Two-year OS rate was 79 %. Acute and late grade 2 toxicities were observed in 8 patients (47 %). No patient experienced late grade ≥3 toxicity. Late toxicity included fibrosis of skin, hypoacusia, dysphagia, and xerostomia. Patients with higher Karnofsky performance status scores associated with a lower risk of mortality (HR 0.85, p = 0.015). Conclusion. Reirradiation with HT in patients with LRNPC is feasible and yields encouraging results in terms of local control and overall survival with acceptable toxicity (AU)

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Effectiveness and toxicity of helical tomotherapy for patients with locally recurrent nasopharyngeal carcinoma.

PURPOSE: We assessed therapeutic outcomes of reirradiation with helical tomotherapy (HT) for locoregional recurrent nasopharyngeal carcinoma (LRNPC) patients. METHODS AND MATERIALS: Treatment outcomes were evaluated retrospectively in 17 consecutive LRNPC patients receiving HT between 2006 and 2012. Median age was 57 years and most patients (n = 13) were male. Simultaneous systemic therapy was applied in 5 patients. Initial treatment covered the gross tumor volume with a median dose of 70 Gy (60-81.6 Gy). Reirradiation was confined to the local relapse region with a median dose of 63 Gy (50-70.2 Gy), resulting in a median cumulative dose of 134 Gy (122-148.2 Gy). The median time interval between initial and subsequent treatment was 42 months (11-126). RESULTS: The median follow-up for the entire cohort was 23 and 35 months for survivors. Three patients (18 %) developed both local and distant recurrences and only one patient (6 %) suffered from isolated local recurrence. Two-year actuarial DFS and LC rates were 74 and 82 %, respectively. Two-year OS rate was 79 %. Acute and late grade 2 toxicities were observed in 8 patients (47 %). No patient experienced late grade ≥3 toxicity. Late toxicity included fibrosis of skin, hypoacusia, dysphagia, and xerostomia. Patients with higher Karnofsky performance status scores associated with a lower risk of mortality (HR 0.85, p = 0.015). CONCLUSION: Reirradiation with HT in patients with LRNPC is feasible and yields encouraging results in terms of local control and overall survival with acceptable toxicity.

Outcome and toxicity using helial tomotherapy for craniospinal irradiation in pediatric medulloblastoma

PURPOSE: The objective of this study is to evaluate the tolerability and outcome of craniospinal irradiation (CSI) with helical tomotherapy (HT) in the treatment of medulloblastoma. METHODS: We evaluated 19 consecutive patients with primary medulloblastoma who were treated with HT from 2007 through 2010. HT regimens to the neuroaxis included: 23.4 Gy at 1.8 Gy/fraction (N = 10), 36 Gy at 1.8 Gy/fraction (N = 7), and 39 Gy bid at 1.3 Gy/fraction (N = 2). The tumor bed received 54-60 Gy. Potential associations between patient, treatment, and toxicity factors and overall survival (OS) were assessed in univariate analyses using the Cox proportional hazards model. Spearman's rank correlation coefficient was used to correlate potential risk factors with the grade of acute toxicity. RESULTS: The median age at diagnosis was 5 years (range 2-14) and the median follow-up for alive patients (N = 14) 40 months (range 10-62). Two- and three-year overall survival was 75 and 68 %, respectively. The most common acute toxicity was hematological (79 %), being grade 2 and grade 3 in 4 (21 %) and 11 (58 %) cases, respectively. No grade ≥2 late toxicities were observed. Higher grades of acute body toxicity were found in older children (P = 0.004). Longer time between diagnosis and radiation therapy was correlated with shorter OS (P = 0.03). In addition, higher grades of acute thrombocytopenia were associated with shorter OS (P = 0.03). CONCLUSIONS: CSI delivered with HT for medulloblastoma is well tolerated with low rates of severe acute toxicity. Further research is necessary to assess late toxicity with a longer follow-up (AU)

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Outcome and toxicity using helical tomotherapy for craniospinal irradiation in pediatric medulloblastoma.

PURPOSE: The objective of this study is to evaluate the tolerability and outcome of craniospinal irradiation (CSI) with helical tomotherapy (HT) in the treatment of medulloblastoma. METHODS: We evaluated 19 consecutive patients with primary medulloblastoma who were treated with HT from 2007 through 2010. HT regimens to the neuroaxis included: 23.4 Gy at 1.8 Gy/fraction (N = 10), 36 Gy at 1.8 Gy/fraction (N = 7), and 39 Gy bid at 1.3 Gy/fraction (N = 2). The tumor bed received 54-60 Gy. Potential associations between patient, treatment, and toxicity factors and overall survival (OS) were assessed in univariate analyses using the Cox proportional hazards model. Spearman's rank correlation coefficient was used to correlate potential risk factors with the grade of acute toxicity. RESULTS: The median age at diagnosis was 5 years (range 2-14) and the median follow-up for alive patients (N = 14) 40 months (range 10-62). Two- and three-year overall survival was 75 and 68 %, respectively. The most common acute toxicity was hematological (79 %), being grade 2 and grade 3 in 4 (21 %) and 11 (58 %) cases, respectively. No grade ≥2 late toxicities were observed. Higher grades of acute body toxicity were found in older children (P = 0.004). Longer time between diagnosis and radiation therapy was correlated with shorter OS (P = 0.03). In addition, higher grades of acute thrombocytopenia were associated with shorter OS (P = 0.03). CONCLUSIONS: CSI delivered with HT for medulloblastoma is well tolerated with low rates of severe acute toxicity. Further research is necessary to assess late toxicity with a longer follow-up.

Three or four fractions per week in postoperative high-dose-rate brachytherapy for endometrial carcinoma. The long-term results on vaginal relapses and toxicity

BACKGROUND: High-dose-rate brachytherapy (HDR-BT) is an accepted part of treatment for endometrial carcinoma and is usually performed in 1-2 fractions per week using different total doses and doses per fraction. To reduce the overall treatment time, HDR-BT was administered with a 3-4 days/week schedule. PATIENTS AND METHODS: From June 2003 to December 2008, 164 patients with stage I-IIIc endometrial carcinoma were treated with HDR-BT (4-5 Gy per fraction). The patients were divided into two groups; Group 1 (40/164 patients) was treated with HDR-BT alone (6 fractions; 4 fractions/week) and Group 2 (124/164 patients) was treated with both (External Beam Radiotherapy [EBRT] + HDR-BT: 3 fractions/week). Complications were analyzed using RTOG scores for rectum and bladder and the objective scores of LENT-SOMA for vaginal complications. RESULTS: The mean followup was 48 months. In Group 1, 35 % of patients underwent treatment in ≤10 days and 65 % in >10 days. In Group 2, 53.2 % received treatment in ≤5 days and in 46.8 % in >5 days. Vaginal relapse was observed in only two patients (1.2 %), both having received adjuvant EBRT + HDR-BT. Acute vaginal toxicity appeared in 8.5 % and late vaginal toxicity in 20.7 % of patients with 13.4 % being G1, 6.7 % G2 and only 0.6 % being G4. No statistically significant differences were found in complications in either brachytherapy group regardless of the overall time. CONCLUSION: In our series, three fractions given in 3-5/days after EBRT or six fractions in 10 days, is a safe regimen in terms of complications and local control (AU)

Stereotactic ablative radiotherapy delivered by image-guided helical tomotherapy for extracranial oligometastases

PURPOSE: To investigate the outcomes and risk factors of patients treated with stereotactic ablative radiotherapy (SABR) delivered by image-guided helical tomotherapy (HT) for extracranial oligometastases. METHODS: From August 2006 through July 2011, 42 consecutive patients (median age 69 years [range 16-87]) with oligometastases (≤3) received HT to all known cancer sites (lung, n = 28; liver, n = 12; adrenal, n = 2). Prognostic factors were assessed by Cox's proportional hazards regression analysis. RESULTS: A total of 60 lesions were treated with hypofractionated HT (median dose 39 Gy [range 36-72.5]; median dose per fraction 12 Gy [range 5-20]). Complete or partial response was observed in 40 (54 %) patients. With a median follow-up period of 15 months, 1- and 2-year overall survival (OS) was 84 and 63 %, respectively; and 1- and 2-year local control (LC) was 92 and 86 %, respectively. Four patients had pneumonitis Grade ≥2 and two patients had lower gastrointestinal toxicity Grade ≥2. Only the lack of complete/partial response was associated with higher risk of mortality on univariate (HR = 3.8, P = 0.04) and multivariate (HR = 6.6, P = 0.01) analyses. CONCLUSIONS: SABR delivered by image-guided HT is well tolerated and offers adequate LC with low acute morbidity in patients with extracranial oligometastatic disease. We found that the response to HT was the only predictor for OS (AU)

Hypofractionated helical tomotherapy using 2.5-2.6 Gy daily fractions for localized prostate cancer

BACKGROUND: The purpose of this study is to evaluate the tolerability of hypofractionated helical tomotherapy (HT) in the treatment of localized prostate cancer. MATERIALS AND METHODS: We evaluated 48 patients with primary adenocarcinoma of the prostate (cT1-T3N0M0) who were treated with hypofractionated HT from August 2008 through July 2011. Hypofractionated regimens included: 68.04 Gy at 2.52 Gy/fraction, 70 Gy at 2.5 Gy/fraction, and 70.2 Gy at 2.6 Gy/fraction. Genitourinary (GU) and gastrointestinal (GI) toxicity was scored using the Radiation Therapy Oncology Group scoring system. RESULTS: Thirty-two patients were treated with 68.04 Gy, 5 patients with 70 Gy, and 11 with 70.2 Gy. The median age at diagnosis was 69 years (range 49-87) and the median follow-up 11 months (range 7-40). Grade 2 acute GI toxicity occurred in 9 patients (19 %). No grade 3 or higher acute GI toxicity was observed. Grade 2 and 3 acute GU toxicities occurred in 19 and 6 % of patients, respectively. The incidence of late grade 2 GI and GU toxicity was 4 and 2 %, respectively. No grade 3 or higher late toxicities were observed. Multivariate analysis showed that patients treated at 2.6 Gy/fraction or those who received a total radiation dose ≥70 Gy had higher rates of grade ≥2 acute GU toxicity (P = 0.004 and P = 0.048, respectively). CONCLUSION: Hypofractionated HT in the treatment of localized prostate cancer is well tolerated with no grade 3 or higher early or late GI and GU toxicities. Further research is needed to assess definitive late toxicity and tumor control (AU)

Three or four fractions per week in postoperative high-dose-rate brachytherapy for endometrial carcinoma. The long-term results on vaginal relapses and toxicity.

BACKGROUND: High-dose-rate brachytherapy (HDR-BT) is an accepted part of treatment for endometrial carcinoma and is usually performed in 1-2 fractions per week using different total doses and doses per fraction. To reduce the overall treatment time, HDR-BT was administered with a 3-4 days/week schedule. PATIENTS AND METHODS: From June 2003 to December 2008, 164 patients with stage I-IIIc endometrial carcinoma were treated with HDR-BT (4-5 Gy per fraction). The patients were divided into two groups; Group 1 (40/164 patients) was treated with HDR-BT alone (6 fractions; 4 fractions/week) and Group 2 (124/164 patients) was treated with both (External Beam Radiotherapy [EBRT] + HDR-BT: 3 fractions/week). Complications were analyzed using RTOG scores for rectum and bladder and the objective scores of LENT-SOMA for vaginal complications. RESULTS: The mean followup was 48 months. In Group 1, 35 % of patients underwent treatment in ≤10 days and 65 % in >10 days. In Group 2, 53.2 % received treatment in ≤5 days and in 46.8 % in >5 days. Vaginal relapse was observed in only two patients (1.2 %), both having received adjuvant EBRT + HDR-BT. Acute vaginal toxicity appeared in 8.5 % and late vaginal toxicity in 20.7 % of patients with 13.4 % being G1, 6.7 % G2 and only 0.6 % being G4. No statistically significant differences were found in complications in either brachytherapy group regardless of the overall time. CONCLUSION: In our series, three fractions given in 3-5/days after EBRT or six fractions in 10 days, is a safe regimen in terms of complications and local control.

Stereotactic ablative radiotherapy delivered by image-guided helical tomotherapy for extracranial oligometastases.

PURPOSE: To investigate the outcomes and risk factors of patients treated with stereotactic ablative radiotherapy (SABR) delivered by image-guided helical tomotherapy (HT) for extracranial oligometastases. METHODS: From August 2006 through July 2011, 42 consecutive patients (median age 69 years [range 16-87]) with oligometastases (≤3) received HT to all known cancer sites (lung, n = 28; liver, n = 12; adrenal, n = 2). Prognostic factors were assessed by Cox's proportional hazards regression analysis. RESULTS: A total of 60 lesions were treated with hypofractionated HT (median dose 39 Gy [range 36-72.5]; median dose per fraction 12 Gy [range 5-20]). Complete or partial response was observed in 40 (54 %) patients. With a median follow-up period of 15 months, 1- and 2-year overall survival (OS) was 84 and 63 %, respectively; and 1- and 2-year local control (LC) was 92 and 86 %, respectively. Four patients had pneumonitis Grade ≥2 and two patients had lower gastrointestinal toxicity Grade ≥2. Only the lack of complete/partial response was associated with higher risk of mortality on univariate (HR = 3.8, P = 0.04) and multivariate (HR = 6.6, P = 0.01) analyses. CONCLUSIONS: SABR delivered by image-guided HT is well tolerated and offers adequate LC with low acute morbidity in patients with extracranial oligometastatic disease. We found that the response to HT was the only predictor for OS.

SU-E-T-290: Dosimetric Verification of Helical Tomotherapy against Experimental Measurements for Head and Neck Treatments.

PURPOSE: To verify a Tomotherapy plan for a typical head and neck treatment against experimental measurements. METHODS: The treatment plan for a head and neck case was generated by the Tomotherapy treatment planning system (TPS) to deliver ∼70 Gy in 33 sessions to the contoured PTV. The plan was calculated on a CIRS ATOM anthropomorphic phantom that provides a grid spacing of 3×3 cm2 holes to accommodate thermoluminescent detectors (TLD). The plan was verified against experimental measurements carried out by 7 LiF:Mg,Ti (TLD-700) TLD. Up to 20 locations were selected within the irradiated region and three detectors were used simultaneously at each point to decrease the statistical uncertainty. TLD locations were labeled in the planning system and dose comparisons between TPS prediction and experimental measurements were performed in terms of absolute dose to water for a single fraction. We examined the dose from (i) the corresponding 3.5MV Tomo-scan alone and (ii) the complete treatment. TLD-700 were found to fulfill the requirements of reproducibility, linearity and flat energy response in a previous study. In particular, TLD energy response was previously checked for 6 MV flattening filter free and conventional radiation beams under reference conditions. RESULTS: Doses derived from the TPS were in most cases in good agreement (4% on average) with TLD dose measurements within TLD statistical uncertainties (about 3%). Larger discrepancies up to 7% were found for points close to complex tissue inhomogeneities, such as bony structures. Dose from the scanning procedure alone is about 1 % of the dose per fraction. CONCLUSIONS: This work indicates that dose delivery plans created with Tomotherapy TPS are accurate for head and neck tumor localizations.

Comparison of positron emission tomography (PET) and computed tomography (CT) for better target volume definition in radiation therapy planning

BACKGROUND: In cancer patients, positron emission tomography/ computed tomography (PET/CT) fused images present less variability in target contouring, respect to use only CT images, respectively. However, the gold standard has not yet been clearly established between radiation oncologists with regard to PET images and the methodology of contouring targets with confidence using PET/CT fused images. The aim of this study was to determine whether integrated PET/CT fused images provide advantages in virtual simulation compared with morphological contouring only with CT. MATERIAL AND METHODS: Thirty cancer patients were evaluated in an adapted PET/CT hybrid in radiotherapy (RT) setup position, with 20 of them being suitable for RT: 17 were suitable for curative intent, which was the group of interest in this study. All image series were sent to the RT work station (WS) where CT and PET series were automatically fused by Digital Imaging and Communications in Medicine (DICOM) in each case. PET series were threshold and were subjected to source-to-background contrast algorithms to fi nally redefine the original tumour description. Three different radiotherapy plans (RTP) for each patient were compared after targets were contoured: [1] planning over metabolic (PET) contoured targets, [2] planning over only morphologic (CT) targets, and [3] planning over targets obtained for treatment based on fused PET/CT images. RESULTS: PET/CT findings altered initial-stage planning in four patients (23.5%) because they had been undergoing chemotherapy. Gross target volume (GTV) and planning target volume (PTV) based only on PET showed more homogeneity to obtain mean doses (p = 0.025) with respect to those based on PET/CT, respectively. However, no percentage differences were observed in median PTV doses between the planning methods, although there was higher variability in PET/CT planning. Morphological (CT) and PET/ CT target volumes were more voluminous than metabolic (PET) volumes. On the other hand, 20% of metabolic (PET) PTV were out of those defined by PET/CT. Thoracic RT plans based on PET preserved better bilateral lung [percentage volume of lung irradiated with a dose of 20 Gy (V20); significance, R(2) = 0.559, p = 0.006]. CONCLUSIONS: For our physicians, PET/CT fused images allowed better contouring of primary tumours in 40% of head and neck cancers and 34% of thoracic cancers. PET/CT provides useful information for virtual simulation therapy. Image treatment and planning in an RT workstation is mandatory (AU)

Use of an electron spoiler for radiation treatment of surface skin diseases

OBJECTIVES: Low-energy electron beams are characterised by low surface doses with a pronounced dose build-up and penetration of several centimetres, but often a higher surface dose and a lower penetration range is desired. The purpose of this study was to investigate the use of an electron spoiler to modify these beams for treating surface skin diseases and evaluate the feasibility of this method. MATERIALS AND METHODS: An aluminium foil 4-mm thick covering the end of the electron applicator was used as a spoiler for a 6 MeV electron beam. The dosimetric characteristics of this beam were measured, and Monte Carlo simulations were performed. RESULTS: The spoiler reduced the practical range and increased surface and build-up doses, but it also significantly broadened the penumbra and increased peripheral doses. Nevertheless, the beam was clinically acceptable when skin collimation with lead was employed. Monte Carlo simulations agreed well with all the experimental measurements. CONCLUSIONS: The feasibility of using a low-energy electron beam with a spoiler for treating surface skin diseases was demonstrated. The method is hygienic and avoids some of the disadvantages associated with the bolus technique, but it is valid only for flat surfaces and perpendicular incidence. As a consequence, it can be an alternative to bolus and other reported methods in certain cases, especially when a particular sterility assurance level is required (AU)

Cell proliferation kinetics and genotoxicity in lymphocytes of smokers living in Mexico City.

Genotoxicity caused by tobacco smoke was assessed in peripheral blood lymphocytes of smokers living in Mexico City by determining sister chromatid exchange (SCE), cell proliferation kinetics (CPK), replication index (RI) and mitotic index (MI). Nicotine levels, and its major metabolite cotinine, were also estimated in urine samples using gas-chromatography-mass spectrometry to quantify smoking intensity. The outcome of the analysis and the comparison of the 77-smoker group with a non-smoking control group showed that moderate and heavy smokers exhibited significant differences (P < 0.001 and P < 0.05, respectively) in CPK, with an underlying delay in the cellular cycle; similarly, RI was significantly different in these groups (P < 0.001 and P < 0.0001, respectively). There were significant correlations (P < 0.05) between age and number of years the subject had been smoking, as well as between RI and nicotine and cotinine levels and between CPK (M1, M2 and M3) and nicotine and cotinine levels. Smokers were classified for the analysis according to the nicotine levels (it is in relation to number of cigarettes smoked per day) found in urine (ng/mL) as: light (10-250), moderate (251-850) and heavy (851-4110). Significant differences in CPK were found (P < 0.05) between moderate and heavy smokers and non-smokers. Significant differences in RI were found between moderate (P < 0.001) and heavy smokers (P < 0.0001) and non-smokers, but not for the light smoking group. MI was determined in 57 of the smokers, whereas SCE frequency was only recorded in 34 smokers. Both parameters yielded no significant differences, nor correlations with any of the assessed variables. In conclusion, cytokinetic and cytostatic effects were mainly detected in heavy and moderate smokers. Cell cycle delay and RI decrease were found in all ;healthy' smokers. The nicotine and cotinine exposure (causing oxidative damage to DNA) may have implications in the decrease in cell replication due to direct damage to DNA and/or a decrease in the DNA repair mechanisms. Alternatively, nicotine and cotinine may possibly induce apoptosis.

El proceso tecnológico en Radioterapia. Su relevancia clínica / The technological process in Radiotherapy. Its clinical relevance

El objetivo de este trabajo e sir desarrollando y comentando los diversos avances que se han producido en las fases fundamentales del tratamiento de radioterapia así como señalar cuales pueden ser los futuros posibles desarrollos de los mismos. De una forma clara y simple se abordan los grandes avances tecnológicos producidos en los últimos años y s repercusión en la mejora y precisión de la radioterapia (AU)

This work mentions the different developments produced in the fundamental phases of Radiotherapy treatment, as well as the possible developments which may be produced in the future (AU)

Photonuclear isotope characterization of a Siemens KDS 18 MV linac head.

Induced activity due to photonuclear reactions produced in the vacuum window of the accelerating wave-guide, the x-ray target and the beam-flattening filter of an 18 MV Siemens KDS linac has been studied. Measurements were performed using a high-purity portable germanium detector. Radioisotopes such as 196Au, 57Co, 60Co and other traces were detected one week after the last clinical use of the linac.

Integrating concurrent navelbine and cisplatin to hyperfractionated radiotherapy in locally advanced non-small cell lung cancer patients treated with induction and consolidation chemotherapy: feasibility and activity results.

OBJECTIVES: The purpose of this study was to determine the effectiveness and toxicity of a new combination schedule based on concurrent navelbine, cisplatin and hyperfractionated radiotherapy in patients with locally advanced NSCLC treated with platinum and gemcitabine induction and consolidation chemotherapy. MATERIALS AND METHODS: The 37 patients with pathological confirmed advanced NSCLC (non-surgical stages IIIA and IIIB) were included in the study. All of them were assessable for survival and 32 for response. The treatment schedule consisted of cisplatin (100 mg/m2) or carboplatin (400 mg/m2) on day 1 with gemcitabine (1000 mg/m2) on days 1, 8 and 15. Treatment was given every 28 days for two courses, followed by concurrent administration of accelerated modified hyperfractionated radiotherapy, with concomitant boost, with a total dose of 61.64 Gy administered for 5 weeks, with cisplatin and navelbine, for two courses, finally followed by two courses of the same initial chemotherapy. RESULTS: Four patients achieved complete response (12.5%) and 14 (44%) partial response, for an overall objective response rate of 56.5%. After a minimum follow-up duration of 35.5 months, median progression free survival was 12.2 months. The median survival was 15.4 months with actuarial 1-, 2- and 3-year survival of 67, 21 and 15%, respectively. The main toxicity was hematological. There was esophagitis (grades III and IV) in 30% of the patients and there were two treatment-related deaths. CONCLUSION: Combined treatment with concurrent radiotherapy and chemotherapy in non-surgical NSCLC is an acceptable treatment modality. However, the toxicity was not negligible.

Characterization of a high-dose-rate 90Sr-90Y source for intravascular brachytherapy by using the Monte Carlo code PENELOPE.

Radiation treatment with catheter-based beta-emitter sources is currently under clinical trial to prevent restenosis. In the present paper, we address the characterization of the high-dose-rate 90Sr-90Y seeds of the Beta-Cath system supplied by Novoste Corporation, one of the commercially available sources for intravascular brachytherapy. The Monte Carlo code PENELOPE has been used to simulate the transport of electrons emitted by the encapsulated 90Sr-90Y seeds. The calculated radial dose function and anisotropy function for a single seed in water are compared with simulation results from other authors. Regarding g(r), the present result lies between the ITS3 and EGS4 curves, being somewhat closer to ITS3, while in the case of F(r, theta) some differences appear for certain angular intervals and radial distances. In order to put the observed differences into perspective, we have calculated radial doses for point isotropic sources in water. Our results for 0.5 and 1 MeV electrons are in good agreement with simulations using EGSnrc, and an excellent agreement is obtained with ITS for point 90Sr-90Y emitters. Dose distributions in water are calculated for source 'trains' consisting of 1, 2, 3, 4, 5, 9 and 12 seeds. The dose at the source midplane is enhanced if the number of seeds is up to 4, and saturates for trains with 5 or more seeds. We also compare the dose distribution obtained by simply adding the contributions of individual seeds with the simulation of the complete source train. It is found that both calculation procedures yield essentially the same result for distances greater than about 2 mm. Finally, the contribution of bremsstrahlung photons to the dose is briefly analysed.