Typical values of z-resolution for different Digital Breast Tomosynthesis systems evaluated in a multicenter study.

PURPOSE: The aim of the present study, conducted by a working group of the Italian Association of Medical Physics (AIFM), was to define typical z-resolution values for different digital breast tomosynthesis (DBT) models to be used as a reference for quality control (QC). Currently, there are no typical values published in internationally agreed QC protocols. METHODS: To characterize the z-resolution of the DBT models, the full width at half maximum (FWHM) of the artifact spread function (ASF), a technical parameter that quantifies the signal intensity of a detail along reconstructed planes, was analyzed. Five different commercial phantoms, CIRS Model 011, CIRS Model 015, Modular DBT phantom, Pixmam 3-D, and Tomophan, were evaluated on reconstructed DBT images and 82 DBT systems (6 vendors, 9 models) in use at 39 centers in Italy were involved. RESULTS: The ASF was found to be dependent on the detail size, the DBT angular acquisition range, the reconstruction algorithm and applied image processing. In particular, a progressively greater signal spread was observed as the detail size increased and the acquisition angle decreased. However, a clear correlation between signal spread and angular range width was not observed due to the different signal reconstruction and image processing strategies implemented in the algorithms developed by the vendors studied. CONCLUSIONS: The analysis led to the identification of typical z-resolution values for different DBT model-phantom configurations that could be used as a reference during a QC program.

The Risk for Schizophrenia-Bipolar Spectrum: Does the Apple Fall Close to the Tree? A Narrative Review.

Schizophrenia (SCZ) and bipolar disorder (BD) are severe psychiatric disorders that share clinical features and several risk genes. Important information about their genetic underpinnings arises from intermediate phenotypes (IPs), quantifiable biological traits that are more prevalent in unaffected relatives (RELs) of patients compared to the general population and co-segregate with the disorders. Within IPs, neuropsychological functions and neuroimaging measures have the potential to provide useful insight into the pathophysiology of SCZ and BD. In this context, the present narrative review provides a comprehensive overview of the available evidence on deficits in neuropsychological functions and neuroimaging alterations in unaffected relatives of SCZ (SCZ-RELs) and BD (BD-RELs). Overall, deficits in cognitive functions including intelligence, memory, attention, executive functions, and social cognition could be considered IPs for SCZ. Although the picture for cognitive alterations in BD-RELs is less defined, BD-RELs seem to present worse performances compared to controls in executive functioning, including adaptable thinking, planning, self-monitoring, self-control, and working memory. Among neuroimaging markers, SCZ-RELs appear to be characterized by structural and functional alterations in the cortico-striatal-thalamic network, while BD risk seems to be associated with abnormalities in the prefrontal, temporal, thalamic, and limbic regions. In conclusion, SCZ-RELs and BD-RELs present a pattern of cognitive and neuroimaging alterations that lie between patients and healthy individuals. Similar abnormalities in SCZ-RELs and BD-RELs may be the phenotypic expression of the shared genetic mechanisms underlying both disorders, while the specificities in neuropsychological and neuroimaging profiles may be associated with the differential symptom expression in the two disorders.

Consensus Report of the Technical-Scientific Associations of Italian Dental Hygienists and the Academy of Advanced Technologies in Oral Hygiene Sciences on the Non-Surgical Treatment of Peri-Implant Disease.

BACKGROUND: The recent publication of the new classification of periodontal and peri-implant disease has given clear indications on the parameters to be taken into consideration to correctly diagnose the different phases of these diseases. To date, however, there are no equally clear indications on the treatments to be implemented to solve these diseases. The objective of this Consensus Report is to provide guidance for the non-surgical management of peri-implant mucositis and peri-implantitis. For the drafting of the consensus, the most recent scientific literature was analysed. MATERIALS AND METHODS: A group of 15 expert Italian dental hygienists were selected by the Italian technical-scientific societies (AIDI, UNID and ATASIO) and, starting from the literature review, they formulated indications according to the GRADE method (Grading of Recommendations, Assessment, Development, and Evaluation, a tool for rating the quality of evidence, used to draw up systematic reviews and clinical guidelines) on the treatment of peri-implant mucositis, peri-implantitis and on management of the various implanting surfaces. CONCLUSIONS: in accordance with the international literature, non-surgical therapy alone can resolve peri-implant mucositis, but not peri-implantitis. Several adjunctive therapies have been considered and some appear to be helpful in managing inflammation.

Brain mechanisms underlying catatonia: A systematic review.

BACKGROUND: Catatonia is a complex psychomotor disorder characterized by motor, affective, and behavioral symptoms. Despite being known for almost 150 years, its pathomechanisms are still largely unknown. METHODS: A systematic research on PubMed, Web of Science, and Scopus was conducted to identify neuroimaging studies conducted on group or single individuals with catatonia. Overall, 33 studies employing structural magnetic resonance imaging (sMRI, n = 11), functional magnetic resonance imaging (fMRI, n = 10), sMRI and fMRI (n = 2), functional near-infrared spectroscopy (fNIRS, n = 1), single positron emission computer tomography (SPECT, n = 4), positron emission tomography (PET, n = 4), and magnetic resonance spectroscopy (MRS, n = 1), and 171 case reports were retrieved. RESULTS: Observational sMRI studies showed numerous brain changes in catatonia, including diffuse atrophy and signal hyperintensities, while case-control studies reported alterations in fronto-parietal and limbic regions, the thalamus, and the striatum. Task-based and resting-state fMRI studies found abnormalities located primarily in the orbitofrontal, medial prefrontal, motor cortices, cerebellum, and brainstem. Lastly, metabolic and perfusion changes were observed in the basal ganglia, prefrontal, and motor areas. Most of the case-report studies described widespread white matter lesions and frontal, temporal, or basal ganglia hypoperfusion. CONCLUSIONS: Catatonia is characterized by structural, functional, perfusion, and metabolic cortico-subcortical abnormalities. However, the majority of studies and case reports included in this systematic review are affected by considerable heterogeneity, both in terms of populations and neuroimaging techniques, which calls for a cautious interpretation. Further elucidation, through future neuroimaging research, could have great potential to improve the description of the neural motor and psychomotor mechanisms underlying catatonia.

Atezolizumab plus bevacizumab versus lenvatinib or sorafenib in non-viral unresectable hepatocellular carcinoma: an international propensity score matching analysis.

BACKGROUND: A growing body of evidence suggests that non-viral hepatocellular carcinoma (HCC) might benefit less from immunotherapy. MATERIALS AND METHODS: We carried out a retrospective analysis of prospectively collected data from consecutive patients with non-viral advanced HCC, treated with atezolizumab plus bevacizumab, lenvatinib, or sorafenib, in 36 centers in 4 countries (Italy, Japan, Republic of Korea, and UK). The primary endpoint was overall survival (OS) with atezolizumab plus bevacizumab versus lenvatinib. Secondary endpoints were progression-free survival (PFS) with atezolizumab plus bevacizumab versus lenvatinib, and OS and PFS with atezolizumab plus bevacizumab versus sorafenib. For the primary and secondary endpoints, we carried out the analysis on the whole population first, and then we divided the cohort into two groups: non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) population and non-NAFLD/NASH population. RESULTS: One hundred and ninety patients received atezolizumab plus bevacizumab, 569 patients received lenvatinib, and 210 patients received sorafenib. In the whole population, multivariate analysis showed that treatment with lenvatinib was associated with a longer OS [hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.44-0.95; P = 0.0268] and PFS (HR 0.67; 95% CI 0.51-0.86; P = 0.002) compared to atezolizumab plus bevacizumab. In the NAFLD/NASH population, multivariate analysis confirmed that lenvatinib treatment was associated with a longer OS (HR 0.46; 95% CI 0.26-0.84; P = 0.0110) and PFS (HR 0.55; 95% CI 0.38-0.82; P = 0.031) compared to atezolizumab plus bevacizumab. In the subgroup of non-NAFLD/NASH patients, no difference in OS or PFS was observed between patients treated with lenvatinib and those treated with atezolizumab plus bevacizumab. All these results were confirmed following propensity score matching analysis. By comparing patients receiving atezolizumab plus bevacizumab versus sorafenib, no statistically significant difference in survival was observed. CONCLUSIONS: The present analysis conducted on a large number of advanced non-viral HCC patients showed for the first time that treatment with lenvatinib is associated with a significant survival benefit compared to atezolizumab plus bevacizumab, in particular in patients with NAFLD/NASH-related HCC.

The neural bases of tactile vitality forms and their modulation by social context.

People communicate using speech, gestures, and, less frequently, touches. An example of tactile communication is represented by handshake. Customs surrounding handshake vary in different cultures. In Western societies is mostly used when meeting, parting, as a sign of congratulations or at the end of a successful business. Despite its importance in social life, the neural mechanism underlying the affective components conveyed by handshake ("tactile vitality forms") is unknown. Here we combined functional magnetic resonance imaging (fMRI) and electromyography (EMG), to investigate the neural affective activations during handshakes. We demonstrated that handshake conveying gentle or aggressive tactile vitality forms produces a stronger activation of the dorso-central insula. The simultaneous presence of emotional facial expressions modulates the activation of this insular sector. Finally, we provide evidence that the cingulate cortex is involved in the processing of facial expressions conveying different vitality forms.

CHARACTERIZATION OF TWO CT SYSTEMS USING A CHANNELIZED HOTELLING OBSERVER AND NPS METRIC.

We investigated the performances of two computed tomography (CT) systems produced by the same manufacturers (Somatom Flash and Edge Siemens) with different detector technologies (Ultrafast Ceramic and Stellar) and different generation of iterative reconstruction (IR) algorithms (SAFIRE and ADMIRE). A homemade phantom was scanned and the images were reconstructed with filtered back-projection (FBP) and IR algorithms. In terms of image quality, the performances of the systems were checked using the low-contrast detectability, evaluated by a Channelized Hotelling Observer (CHO), and the noise power spectrum (NPS). The analysis with CHO showed the best performance of Edge respect to Flash system for both FBP and IR algorithms. This better behavior, which reaches 20%, has been ascribed to the Stellar detector. From the NPS analysis, the noise reduction due to Stellar detector was 57%, moreover ADMIRE algorithm preserves a more traditional CT image texture appearance versus SAFIRE due to a lower NPS peak shift.

Transfection of bovine fetal fibroblast with polyethylenimine (PEI) nanoparticles: effect of particle size and presence of fetal bovine serum on transgene delivery and cytotoxicity.

The development of efficient transfection protocols for livestock cells is crucial for implementation of cell-based transgenic methods to produce genetically modified animals. We synthetized fully deacylated linear 22, 87 and 217 kDa polyethylenimine (PEI) nanoparticles and compared their transfection efficiency and cytotoxicity to commercial branched 25 kDa PEI and linear 58 kDa poly(allylamine) hydrochloride. We studied the effect of PEI size and presence of serum on transfection efficiency on primary cultures of bovine fetal fibroblasts and established cells lines (HEK 293 and Hep G2). We found that transfection efficiency was affected mainly by polymer/pDNA ratio and DNA concentration and in less extent by PEI MW. In bovine fibroblast, preincubation of PEI nanoparticles with fetal bovine serum (FBS) greatly increased percentage of cells expressing the transgene (up to 82%) while significantly decreased the polymer cytotoxic effect. 87 and 217 kDa PEI rendered the highest transfection rates in HEK 293 and Hep G2 cell lines (>50% transfected cells) with minimal cell toxicity. In conclusion, our results indicate that fully deacylated PEI of 87 and 217 kDa are useful DNA vehicles for non-viral transfection of primary cultures of bovine fetal fibroblast and HEK 293 and Hep G2 cell lines.

Stearoyl-CoA desaturase 1 and paracrine diffusible signals have a major role in the promotion of breast cancer cell migration induced by cancer-associated fibroblasts.

BACKGROUND: Despite the recognised contribution of the stroma to breast cancer development and progression, the effective targeting of the tumor microenvironment remains a challenge to be addressed. We previously reported that normal fibroblasts (NFs) and, notably, breast cancer-associated fibroblasts (CAFs) induced epithelial-to-mesenchymal transition and increases in cell membrane fluidity and migration in well- (MCF-7) and poorly-differentiated (MDA-MB-231) breast cancer cells. This study was designed to better define the role played, especially by CAFs, in promoting breast tumor cell migration. METHODS: Fibroblast/breast cancer cell co-cultures were set up to investigate the influence of NFs and CAFs on gene and protein expression of Stearoyl-CoA desaturase 1 (SCD1), the main enzyme regulating membrane fluidity, as well as on the protein level and activity of its transcription factor, the sterol regulatory element-binding protein 1 (SREBP1), in MCF-7 and MDA-MB-231 cells. To assess the role of SREBP1 in the regulation of SCD1 expression, the desaturase levels were also determined in tumor cells treated with an SREBP1 inhibitor. Migration was evaluated by wound-healing assay in SCD1-inhibited (by small-interfering RNA (siRNA) or pharmacologically) cancer cells and the effect of CAF-conditioned medium was also assessed. To define the role of stroma-derived signals in cancer cell migration speed, cell-tracking analysis was performed in the presence of neutralising antibodies to hepatocyte growth factor, transforming growth factor-ß or basic fibroblast growth factor. RESULTS: A two to three fold increase in SCD1 mRNA and protein expression has been induced, particularly by CAFs, in the two cancer cell lines that appear to be dependent on SREBP1 activity in MCF-7 but not in MDA-MB-231 cells. Both siRNA-mediated and pharmacological inhibition of SCD1 impaired tumor cells migration, also when promoted by CAF-released soluble factors. Fibroblast-triggered increase in cancer cell migration speed was markedly reduced or abolished by neutralising the above growth factors. CONCLUSION: These results provide further insights in understanding the role of CAFs in promoting tumor cell migration, which may help to design new stroma-based therapeutic strategies.

[Ultrasonographic and clinical methods in the management of prolonged pregnancy]. / Confronto tra metodiche cliniche e strumentali nella gestione della gravidanza protratta.

AIM: The aim of this study was to evaluate the role of Bishop score, sonographic measurements of uterine cervical length and maternal characteristics, as predictors of spontaneous onset of labor within 24 hours, as well as response to induction in prolonged pregnancies. METHODS: Pregnancies with gestational age over 280 days were followed as outpatient. Patients were included in the study if spontaneous delivery occurred between 286 and 295 days of gestation, or in pregnancies with gestational age of 291-293 days who required labor induction. Data about Bishop score, ultrasonographic cervical characteristics (length, funneling, volume) and maternal features (parity, body mass index and age) registered at the last control immediately before the delivery were retrieved from clinical charts. RESULTS: Data from 195 patients were available. Bishop score and, in particular, ultrasonographic cervical length can predict the spontaneous onset of labor with a positive predictive value (PPV) of 22% and 44%, respectively in 24 hours. On the other hands, in patients requiring labor induction, parity and ultrasonographic cervical length remained the only predictive parameters with a PPV of 39% and 42%, respectively. In term of predictive performance, the value of 30 mm was identified as the best cut-off value for the ultrasonographic cervical length (specificity 59% and sensitivity 69%). CONCLUSION: In prolonged pregnancies, Bishop score and ultrasonographic cervical length were shown to be relevant in the prediction of spontaneous onset of labor, while in patients who required labor induction, ultrasonographic cervical length represented the only clinic parameter predicting the onset of labor.

Genotypes B and C hepatocellular carcinoma-associated hepatitis B virus pre-S mutants: their detection among F1b and A2 - but not F4 - isolates from Argentina.

Prevalence rates of hepatocellular carcinoma (HCC)-associated hepatitis B virus (HBV) pre-S mutants among most genotypes are still lacking. In this study, viral (sub)genotypes of 70 Argentine nucleotide sequences (33 newly obtained) were determined by phylogenetic analysis, and the presence of such mutants was assessed in the American continent for the first time. Nucleotide substitutions of the pre-S2 start codon were observed in 10% of the HBV/A2 sequences. Ten per cent of the HBV/A2 and 12.5% of the HBV/F1b - but none of HBV/F4 - exhibited a deletion in the pre-S1/pre-S2 region. The contribution of these variants to liver cirrhosis (LC) and/or HCC development among HBV/F and HBV/A isolates deserves further prospective clinical studies.

Metachronous contralateral Leydig-cell tumour in an 8-year-old boy.

Leydig-cell tumours of the testis are rare and usually benign in children. The possibility of metachronous bilateral tumours should be considered not only for testicular teratomas but also in the follow up of a Leydig-cell tumour. Testis-sparing surgery is feasible and safe in prepubertal boys after exclusion of a malignant tumour.

Effective count rates for PET scanners with reduced and extended axial field of view.

We investigated the relationship between noise equivalent count (NEC) and axial field of view (AFOV) for PET scanners with AFOVs ranging from one-half to twice those of current clinical scanners. PET scanners with longer or shorter AFOVs could fulfill different clinical needs depending on exam volumes and site economics. Using previously validated Monte Carlo simulations, we modeled true, scattered and random coincidence counting rates for a PET ring diameter of 88 cm with 2, 4, 6, and 8 rings of detector blocks (AFOV 7.8, 15.5, 23.3, and 31.0 cm). Fully 3D acquisition mode was compared to full collimation (2D) and partial collimation (2.5D) modes. Counting rates were estimated for a 200 cm long version of the 20 cm diameter NEMA count-rate phantom and for an anthropomorphic object based on a patient scan. We estimated the live-time characteristics of the scanner from measured count-rate data and applied that estimate to the simulated results to obtain NEC as a function of object activity. We found NEC increased as a quadratic function of AFOV for 3D mode, and linearly in 2D mode. Partial collimation provided the highest overall NEC on the 2-block system and fully 3D mode provided the highest NEC on the 8-block system for clinically relevant activities. On the 4-, and 6-block systems 3D mode NEC was highest up to ∼300 MBq in the anthropomorphic phantom, above which 3D NEC dropped rapidly, and 2.5D NEC was highest. Projected total scan time to achieve NEC-density that matches current clinical practice in a typical oncology exam averaged 9, 15, 24, and 61 min for the 8-, 6-, 4-, and 2-block ring systems, when using optimal collimation. Increasing the AFOV should provide a greater than proportional increase in NEC, potentially benefiting patient throughput-to-cost ratio. Conversely, by using appropriate collimation, a two-ring (7.8 cm AFOV) system could acquire whole-body scans achieving NEC-density levels comparable to current standards within long, but feasible, scan times.

A robust state-space kinetics-guided framework for dynamic PET image reconstruction.

Dynamic PET image reconstruction is a challenging issue due to the low SNR and the large quantity of spatio-temporal data. We propose a robust state-space image reconstruction (SSIR) framework for activity reconstruction in dynamic PET. Unlike statistically-based frame-by-frame methods, tracer kinetic modeling is incorporated to provide physiological guidance for the reconstruction, harnessing the temporal information of the dynamic data. Dynamic reconstruction is formulated in a state-space representation, where a compartmental model describes the kinetic processes in a continuous-time system equation, and the imaging data are expressed in a discrete measurement equation. Tracer activity concentrations are treated as the state variables, and are estimated from the dynamic data. Sampled-data H(∞) filtering is adopted for robust estimation. H(∞) filtering makes no assumptions on the system and measurement statistics, and guarantees bounded estimation error for finite-energy disturbances, leading to robust performance for dynamic data with low SNR and/or errors. This alternative reconstruction approach could help us to deal with unpredictable situations in imaging (e.g. data corruption from failed detector blocks) or inaccurate noise models. Experiments on synthetic phantom and patient PET data are performed to demonstrate feasibility of the SSIR framework, and to explore its potential advantages over frame-by-frame statistical reconstruction approaches.

Use of preputial skin as cutaneous graft after nevus excision.

We report a four-year-old boy with a nevus covering all the plantar side of his second finger on the left foot. He was also affected by congenital phimosis. Surgical excision of the nevus was indicated, but the skin defect would have been too large to be directly closed. The foreskin was taken as a full-thickness skin graft to cover the cutaneous defect of the finger. The graft intake was favourable and provided a functional repair with good aesthetic characteristic.

Relationship between environmental factors and gray matter atrophy in refractory MTLE.

OBJECTIVE: To investigate clinical, neuropsychological, and MRI abnormalities (gray matter atrophy [GMA] and white matter atrophy [WMA]) in surgical mesial temporal lobe epilepsy (MTLE) patients with and without familial antecedent for epilepsy. METHODS: A cohort study including 69 operated patients with unilateral MTLE, divided into a group of 29 patients (mean age 35.8 +/- 10.4 years) with a negative family history (FH) of epilepsy and a group of 40 patients (32.8 +/- 10 years) with a positive FH. We performed voxel-based morphometry (VBM) on preoperative MRIs and investigated possible clinical and neuropsychological differences between the 2 groups. We also performed VBM and t tests to compare the patients' groups with normal controls. RESULTS: The negative-FH group had lower IQ scores (p = 0.004), performed poorer on the Boston Naming Test (p = 0.02) and on delayed recall (p = 0.03), and presented a more prominent asymmetry index of hippocampal volume (p = 0.04) and more frequent initial precipitating injuries (p = 0.023). VBM showed a more restricted pattern of GMA in the positive-FH group and a more bilateral and widespread pattern of GMA in the negative-FH group, involving thalami, temporal, frontal, parietal, and occipital lobes. WMA was widespread and bilateral in both groups. CONCLUSIONS: The more widespread structural voxel-based morphometry abnormalities and worse IQ performance identified in the negative-family history (FH) group may result from a stronger environmental influence, including initial precipitating injuries. This is further support for the hypothesis that hippocampal sclerosis in mesial temporal lobe epilepsy with positive FH is determined by a stronger genetic predisposition with less influence of environmental factors compared with patients in the negative-FH group.

Noise and signal properties in PSF-based fully 3D PET image reconstruction: an experimental evaluation.

The addition of accurate system modeling in PET image reconstruction results in images with distinct noise texture and characteristics. In particular, the incorporation of point spread functions (PSF) into the system model has been shown to visually reduce image noise, but the noise properties have not been thoroughly studied. This work offers a systematic evaluation of noise and signal properties in different combinations of reconstruction methods and parameters. We evaluate two fully 3D PET reconstruction algorithms: (1) OSEM with exact scanner line of response modeled (OSEM+LOR), (2) OSEM with line of response and a measured point spread function incorporated (OSEM+LOR+PSF), in combination with the effects of four post-reconstruction filtering parameters and 1-10 iterations, representing a range of clinically acceptable settings. We used a modified NEMA image quality (IQ) phantom, which was filled with 68Ge and consisted of six hot spheres of different sizes with a target/background ratio of 4:1. The phantom was scanned 50 times in 3D mode on a clinical system to provide independent noise realizations. Data were reconstructed with OSEM+LOR and OSEM+LOR+PSF using different reconstruction parameters, and our implementations of the algorithms match the vendor's product algorithms. With access to multiple realizations, background noise characteristics were quantified with four metrics. Image roughness and the standard deviation image measured the pixel-to-pixel variation; background variability and ensemble noise quantified the region-to-region variation. Image roughness is the image noise perceived when viewing an individual image. At matched iterations, the addition of PSF leads to images with less noise defined as image roughness (reduced by 35% for unfiltered data) and as the standard deviation image, while it has no effect on background variability or ensemble noise. In terms of signal to noise performance, PSF-based reconstruction has a 7% improvement in contrast recovery at matched ensemble noise levels and 20% improvement of quantitation SNR in unfiltered data. In addition, the relations between different metrics are studied. A linear correlation is observed between background variability and ensemble noise for all different combinations of reconstruction methods and parameters, suggesting that background variability is a reasonable surrogate for ensemble noise when multiple realizations of scans are not available.

[Definitive treatment of anal canal carcinoma with radiotherapy: adverse impact of a pre-radiation resection. A retrospective study of 57 patients treated with curative intent]. / Radiothérapie à visée curative du carcinome du canal anal : impact défavorable d'une résection préalable. Etude rétrospective de 57 patients traités en intention curative.

PURPOSE: To describe retrospectively the overall survival, the cancer specific survival and the tumor control in an homogeneous series of patients with epidermoid carcinoma of the anal canal treated with definitive radiotherapy; to assess the impact of brachytherapy, chemotherapy and pre-radiotherapy resection on the risk of recurrence. PATIENTS AND METHODS: From 1997 to 2007, 57 patients (pts) presenting with an epidermoid carcinoma of the anal canal (T1: 14, T2: 33, T3-4: 10, N0: 31, N1: 19, N2: 3, N3: 4, M0: 57) were treated with definitive radiotherapy by the same radiation oncologist. The treatment included an external beam irradiation (EBRT) given to the posterior pelvis (45Gy/25 fractions) and, six weeks later, a boost delivered with interstitial brachytherapy (37/57) or external beam irradiation (20/57). Twelve pts had undergone a surgical resection of the tumour before radiotherapy. A belly board was used for EBRT in 13 pts. A concurrent platinum based chemotherapy was done in 42 pts. The mean follow-up was 57 months. RESULTS: The overall survival rate at 5 years was 89% with a cause specific survival of 96%. Five patients recurred (5-year rate: 12%: four had local relapse (5-year rate: 8%), four had groin recurrence, and distant metastases were seen in two. In univariate analysis, the risk of relapse was higher in patients who had undergone a pre-radiation excision (p=0.018), in those who did not receive chemotherapy (p=0.076) and in those who were irradiated on a belly board (p=0.049). In multivariate analysis, a pre-radiotherapy resection (p=0.084) had an inverse impact on the tumour control reaching the level of statistical significance and the use of a belly board was of marginal influence (p=0.13). CONCLUSION: Radiotherapy and chemoradiation with cisplatine-based chemotherapy cure a vast majority of patients with epidermoid carcinoma of the anal canal. Therapeutic factors that may interfere with the definition of the target volume and the patients' repositioning may decrease the efficacy of radiotherapy. Pre-radiotherapy surgical resection should be avoided.