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.

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.

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.

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.

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.

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.

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.

Acoustic analysis after radiotherapy in T1 vocal cord carcinoma: a new approach to the analysis of voice quality.

PURPOSE: The study of acoustic voice parameters (fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio) in extended vowel production, oral reading of a standard paragraph, spontaneous speech and a song in irradiated patients for Tis-T1 vocal cord carcinoma. METHODS AND MATERIALS: Eighteen male patients irradiated for Tis-T1 vocal cord carcinoma and a control group of 31 nonirradiated subjects of the same age were included in a study of acoustic voice analysis. The control group had been rigorously selected for voice quality and the irradiated group had previous history of smoking in two-thirds of the cases and a vocal cord biopsy. Radiotherapy patients were treated with a 6MV Linac receiving a total dose of 66 Gy, 2 Gy/day, with median treatment areas of 28 cm(2). Acoustic voice analysis was performed 1 year after radiotherapy, the voice of patients in extended vowel production, oral reading of a standard paragraph, spontaneous speech, and in a song was tape registered and analyzed by a Kay Elemetric's Computerized Speech Lab (model CSL# 4300). Fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio were obtained in each case. Mann Whitney analysis was used for statistical tests. RESULTS: The irradiated group presented higher values of fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio. Mann-Whitney analysis showed significant differences for fundamental frequency and jitter in vowel production, oral reading, spontaneous speech, and song. Shimmer only showed differences in vowel production and harmonics-to-noise ratio in oral reading and song. CONCLUSIONS: In our study only fundamental frequency and jitter showed significant increased values to the control group in all the acoustic situations. Sustained vowel production showed the worst values of the acoustic parameters in comparison with the other acoustic situations. This study seems to suggest that more work should be done in this field.

Oxidative damage of mitochondrial and nuclear DNA induced by ionizing radiation in human hepatoblastoma cells.

PURPOSE: Since reactive oxygen species (ROS) act as mediators of radiation-induced cellular damage, the aim of our studies was to determine the effects of ionizing radiation on the regulation of hepatocellular reduced glutathione (GSH), survival and integrity of nuclear and mitochondrial DNA (mtDNA) in human hepatoblastoma cells (Hep G2) depleted of GSH prior to radiation. METHODS AND MATERIALS: GSH, oxidized glutathione (GSSG), and generation of ROS were determined in irradiated (50-500 cGy) Hep G2 cells. Clonogenic survival, nuclear DNA fragmentation, and integrity of mtDNA were assessed in cells depleted of GSH prior to radiation. RESULTS: Radiation of Hep G2 cells (50-400 cGy) resulted in a dose-dependent generation of ROS, an effect accompanied by a decrease of reduced GSH, ranging from a 15% decrease for 50 cGy to a 25% decrease for 400 cGy and decreased GSH/GSSG from a ratio of 17 to a ratio of 7 for controls and from 16 to 6 for diethyl maleate (DEM)-treated cells. Depletion of GSH prior to radiation accentuated the increase of ROS by 40-50%. The depletion of GSH by radiation was apparent in different subcellular sites, being particularly significant in mitochondria. Furthermore, depletion of nuclear GSH to 50-60% of initial values prior to irradiation (400 cGy) resulted in DNA fragmentation and apoptosis. Consequently, the survival of Hep G2 to radiation was reduced from 25% of cells not depleted of GSH to 10% of GSH-depleted cells. Fitting the survival rate of cells as a function of GSH using a theoretical model confirmed cellular GSH as a key factor in determining intrinsic sensitivity of Hep G2 cells to radiation. mtDNA displayed an increased susceptibility to the radiation-induced loss of integrity compared to nuclear DNA, an effect that was potentiated by GSH depletion in mitochondria (10-15% intact mtDNA in GSH-depleted cells vs. 25-30% of repleted cells). CONCLUSION: GSH plays a critical protective role in maintaining nuclear and mtDNA functional integrity, determining the intrinsic radiosensitivity of Hep G2. Although the DNA repair is a complex process that is not yet completely understood, the protective role of GSH probably does not seem to involve the repair of classical DNA damage but may relate to modification of DNA damage dependent signaling.

Real-size CT slices to optimize brachytherapy in the plastic tube technique for oral cavity neoplasms.

To optimize brachytherapy treatments in the plastic tube technique and to have a quality assurance system, we use Real-Size CT slices (RSCTS). This procedure permits us to have a more precise knowledge of the dose distribution in the tumor and in the healthy neighboring tissues.

Transcriptional regulation of the heavy subunit chain of gamma-glutamylcysteine synthetase by ionizing radiation.

Since glutathione (GSH) protects against oxidative stress, we determined the regulation of cellular GSH by ionizing radiation in human hepatoblastoma cells, HepG2. The levels of GSH increased in irradiated HepG2 due to a greater gamma-glutamylcysteine synthetase (gamma-GCS) activity, which was paralleled by gamma-GCS heavy subunit chain (gamma-GCS-HS) mRNA levels. Transcription of deletion constructs of the gamma-GCS-HS promoter cloned in a reporter vector was associated with activator protein-1 (AP-1), consistent with the DNA binding of AP-1 in nuclear extracts of irradiated HepG2. Hence, the transcriptional regulation of gamma-GCS by ionizing radiation emerges as an adaptive mechanism, which may be of significance to control the consequences of the oxidative stress induced by radiation.

Monte Carlo calculation of the dose distributions of two 106Ru eye applicators.

BACKGROUND AND PURPOSE: Beta emitting 106Ru applicators are widely used to treat choroidal melanoma. In view of the importance of clinical applications of this radioisotope and the relative lack of knowledge of the dose distributions, three-dimensional dose maps of two concave applicators were calculated by means of Monte Carlo simulation. MATERIALS AND METHODS: Simulations of small CCA and CCB concave applicators manufactured by Bebig were performed using the Monte Carlo code PENELOPE, which allows the description of the structure (geometry and materials) of the applicator in detail. Electrons are emitted from the 106Ru nuclei isotropically, with initial energy randomly sampled from the corresponding Fermi spectra and with initial positions uniformly distributed on the radioactive layer. Primary electrons, as well as the produced delta-rays, are assumed to be absorbed in the medium when they slow down to an energy of 70 keV. Bremsstrahlung photons with energies larger than 7 keV are also simulated. The simulation code has been run on a 166 MHz PENTIUM PC. RESULTS: Three-dimensional dose distributions produced by the CCA and CCB applicators in a water sphere, concentric with the applicator, were evaluated. To minimize the magnitude of statistical uncertainties, advantage has been taken of the cylindrical symmetry of the problem. The relative depth-dose (along the symmetry axis of the applicator) was also evaluated from the applicator surface up to distances larger than I cm, with statistical uncertainties of a few percent. Results compare well with data supplied by the manufacturer. CONCLUSIONS: We have performed accurate Monte Carlo calculations of three-dimensional dose distributions from CCA and CCB 106Ru applicators. The results, presented in the form of two-dimensional maps, depth-dose distributions along the symmetry axis and lateral dose profiles, provide a detailed description of the dose delivered in treatments of choroidal melanoma.

Simulation by a diagnostic CT for the early vocal cord carcinoma.

The CT-based simulation with a 3D planning system permits the optimization of radiotherapy treatments. The goal is to obtain an increase in the local control and survival with a reduction of the treatment related toxicity. In our hospital, we do not have a CT simulator and our 3D planning system is not yet working, therefore, we have developed a system to simulate radiotherapy treatments using a diagnostic CT. We began by simulating an early vocal cord carcinoma. The rules of this simulation are presented using a clinical case as an example.

Radiotherapy in the maxillary hemangioma.

We present the case of a large maxillary hemangioma treated by radiotherapy. Only 4 cases managed by radiotherapy have been reported in the literature, and most authors negate the radiosensitivity of the tumor. In our patient, the outcome was excellent; by 6 months tumor reduction was more than 50%. This is the first case referred to in the literature whose radiotherapy response was evaluated by magnetic resonance imaging. We describe the clinical and imaging findings of this very rare tumor and its evolution. We also comment on the literature reviewed.

Quality assurance of interstitial brachytherapy technique in lip cancer: comparison of actual performance with the Paris System recommendations.

This study takes a quality assurance approach to assessing staff application of Paris System recommendations for brachytherapy. Between 1988 and 1992, 72 patients were treated with brachytherapy for cancer of the lip at Hospital Clinic in Barcelona. Because of the relatively high number of total local recurrences (11%) and the fact that several radiotherapists had come from other hospitals to join the staff, we analysed the technique actually used compared with the recommendations of the Paris System. Results indicate our staff did not, in fact, use the active length prescribed by the Paris System in 71% of cases but that the discrepancies had no observable impact on the actuarial local control in the short follow-up period (28 +/- 15 months). When we compared, in time sequence, the first 35 patients treated between 1988 and 1989 (Early group) with the last 37 treated between 1990 and 1992 (Later group), we saw that staff members had improved their application of the therapy by more often using the recommended length of active lines. Staff performance in the Later group was still far from ideal, however, as the actual length used differed from the length recommended in 51% of the cases. At present we are insisting on stricter application of the Paris System guidelines for lip brachytherapy. Our study suggests that auditing performance is worthwhile and we recommend that radiotherapists apply this analytical quality assurance method, especially when several new physicians join a department.

A CT-based simulation for head and neck tumors in centers without CT-simulator and 3D-planning system.

We present a special CT-based simulation technique to optimize the radiotherapy treatments in head and neck tumors. On an immobilization device, some CT hyperdense markers are placed. Real-size CT slices are performed every 5 mm with the patient in the treatment position with the immobilization system. This study permits a more accurate knowledge of the gross tumoral volume and an optimization of the planning treatment.