Surgical treatment of tethered cord syndrome-comparing the results of surgeries with and without electrophysiological monitoring.

PURPOSE: To compare the short- and long-term outcomes after surgical treatment of tethered cord syndrome with and without electrophysiological monitoring. METHOD: We collected the preoperative data of 102 tethered cord surgeries of 91 patients. We compared the outcomes regarding the presence of intraoperative electrophysiology, the types of surgeries and the preoperative neurological condition. We also analysed the long-term outcomes in the cases of 69 patients. RESULTS: We found that intraoperative electrophysiology can reduce the perioperative surgical risk significantly (from 9.4 to 2.9%, p < 0.001), and electrophysiology is also beneficial in avoiding long-term progression in 88.7% (p = 0.03341). CONCLUSION: Tethered cord surgeries are safe and effective. With the use of intraoperative electrophysiology, the risk of postoperative worsening is as low as 2.9%, and long-term progression can be avoided in the majority of the patients.

Moving gantry method for electron beam dose profile measurement at extended source-to-surface distances.

A novel method has been put forward for very large electron beam profile measurement. With this method, absorbed dose profiles can be measured at any depth in a solid phantom for total skin electron therapy. Electron beam dose profiles were collected with two different methods. Profile measurements were performed at 0.2 and 1.2 cm depths with a parallel plate and a thimble chamber, respectively. 108cm × 108 cm and 45 cm × 45 cm projected size electron beams were scanned by vertically moving phantom and detector at 300 cm source-to-surface distance with 90° and 270° gantry angles. The profiles collected this way were used as reference. Afterwards, the phantom was fixed on the central axis and the gantry was rotated with certain angular steps. After applying correction for the different source-to-detector distances and incidence of angle, the profiles measured in the two different setups were compared. Correction formalism has been developed. The agreement between the cross profiles taken at the depth of maximum dose with the 'classical' scanning and with the new moving gantry method was better than 0.5 % in the measuring range from zero to 71.9 cm. Inverse square and attenuation corrections had to be applied. The profiles measured with the parallel plate chamber agree better than 1%, except for the penumbra region, where the maximum difference is 1.5%. With the moving gantry method, very large electron field profiles can be measured at any depth in a solid phantom with high accuracy and reproducibility and with much less time per step. No special instrumentation is needed. The method can be used for commissioning of very large electron beams for computer-assisted treatment planning, for designing beam modifiers to improve dose uniformity, and for verification of computed dose profiles.

[Intraoperativ electrophysiological monitoring during neurosurgery on eloquent structures]. / Intraoperatív elektrofiziológia elokvens idegrendszeri struktúrákat erinto idegsebészeti beavatkozások során.

OBJECTIVE: We summarize our experiences on intraoperative electrophysiological monitoring during neurosurgical procedures on eloquent neuronal structures. PATIENTS, METHODS: Sixty patients were enrolled retrospectively in our study with pathologies involving eloquent neuronal structures. They were operated between May 2011. and March 2012. at the University of Debrecen, Department of Neurosurgery and at the National Institute of Neurosciences. Patients underwent standard preoperative examinations due to the primary pathology. In all cases we used intraoperative electrophysiological monitoring. We had 22 cases with cranial nerve monitoring, 10 cases with cauda monitoring, 16 cases with motor system monitoring, six cases with complex spinal cord monitoring, three degenerative spine reconstructions and 3 awake surgeries. RESULTS: We found that with the use of intraoperative electrophysiology we could make these neurosurgical procedures safer, and were able to optimize the extent of resection in the cases of oncological pathologies. CONCLUSIONS: Our experiences as well as the international literature suggests that in certain high risk neurosurgical procedures intraoperative electrophysiology is indispensible for safe and optimally extended operation.

Radio-neuroprotective effect of L-alpha-glycerylphosphorylcholine (GPC) in an experimental rat model.

Ionizing radiation plays a major role in the treatment of brain tumors, but side-effects may restrict the efficacy of therapy. In the present study, our goals were to establish whether the administration of L-alpha-glycerylphosphorylcholine (GPC) can moderate or prevent any of the irradiation-induced functional and morphological changes in a rodent model of hippocampus irradiation. Anesthetized adult (6-weeks-old) male Sprague-Dawley rats were subjected to 40 Gy irradiation of one hemisphere of the brain, without or with GPC treatment (50 mg/kg bw by gavage), the GPC treatment continuing for 4 months. The effects of this partial rat brain irradiation on the spatial orientation and learning ability of the rats were assessed with the repeated Morris water maze (MWM) test. Histopathologic (HP) evaluation based on hematoxylin-eosin and Luxol blue staining was performed 4 months after irradiation. The 40 Gy irradiation resulted in a moderate neurological deficit at the levels of both cognitive function and morphology 4 months after the irradiation. The MWM test proved to be a highly sensitive tool for the detection of neurofunctional impairment. The site navigation of the rats was impaired by the irradiation, but the GPC treatment markedly decreased the cognitive impairment. HP examination revealed lesser amounts of macrophage density, reactive gliosis, calcification and extent of demyelination in the GPC-treated group. GPC treatment led to significant protection against the cognitive decline and cellular damage, evoked by focal brain irradiation at 40 Gy dose level. Our study warrants further research on the protective or mitigating effects of GPC on radiation injuries.

D-wave recording during the surgery of a 10-month-old child.

PURPOSE: The purpose of this study is to evaluate the possibility of d-wave recording in very young patients during spinal cord surgery. METHOD: A 10-month-old patient was operated on cystic intramedullary pathology and myelon tethering at level cervical VI. to thoracal III. During the surgical detethering, we did d-wave recording for experimental purposes. After transcranial electric stimulation, we tried to detect the responses with epidural d-wave electrodes proximally and distally from the pathology. RESULTS: We found that proximally from the pathology, we could detect reproducible d-waves. CONCLUSION: Though earlier papers reported that due to the immature condition of the myelon d-wave recording is not possible under the age of 21 months, we proved that even in very young patients, the possibility of d-wave recording should not be excluded.

Shunt insufficiency due to knot formation in the peritoneal catheter.

The authors report a rare case of the peripheral obstruction of a ventriculoperitoneal shunt. Premature baby was operated on hydrocephalus due to germinal matrix bleeding. After two months of implantation of venticuloperitoneal shunt peripheral insufficiency of the system was emerged. During the shunt revision extensive knot formation became visible. We simply cut the catheter above the knot and the working shunt was replaced into the abdominal cavity. The postoperative course was uneventful and the baby was free of complaints for more than one year. The pathomechanism of knot formation is not clear thus the discovery of the problem during the operation is an unexpected event. In our opinion tight knot cannot be spontaneously formed intraabdominally. Loose knots can be developed and can reduce the capacity of liquor flow. We think that the knot tightens during pulling out. Longer peritoneal catheters can precipitate multiple looping and/or axial torquations and increase the peripheral resistance of the shunt. In such cases when the pulling out is challenged conversion to laparotomy is suggested.

[The clinical relevance of 1p19q codeletion of oligodendrogliomas at the Department of Neurosurgery in Debrecen]. / Az 1p19q kodeléció klinikaí relevanciájá oligodendrogliomákban a Debreceni Idegsebészeti klinikán.

OBJECT: To determine the clinical relevance of 1p19q codeletion in case of patients treated between 2006 and 2008 with oligodendroglial tumor at the Department of Neurosurgery, University of Debrecen. QUESTIONS: Beside the traditional morphological investigations, methods of rapidly developing molecular pathology are also available for routine diagnostic procedures. Numerous studies confirm that the codeletion of the 1p and 19q alleles has a clinical relevance regarding the sensitivity for chemotherapy. In this study the connection between the 1p19q codeletion and clinical parameters was tested to evaluate the prognostic role of this genetic alteration in neurosurgical patients. METHODS, CLINICAL DATA: In the present study experiences about the clinical relevance of 1p19 codeletion is summarized. Between 2006 and 2008, 28 patients with brain tumor containing oligodendroglial component was tested for 1p19q codeletion. The result of the analysis was compared with clinical data such as tumor localization, extent of resection, histological grade, presence of astrocyte component, time of first recurrence, age and gender. Furthermore, the potency of 1p19q codeletion as a prognostic factor for chemosensitivity by analyzing the data of patients who underwent different treatment protocols was also evaluated. RESULTS: Our results suggest that 1p19q codeletion can be valued as a positive prognostic factor, which is concordant with the results available in the literature. We also found positive correlation with oligodendroglial component, recurrence free survival of grade III tumors, sensitivity to chemo- and radiotherapy, and inverse correlation with histological grade and age was detected. CONCLUSION: Though the 1p19q codeletion is currently not the part of the routine patient management, based on our study we found it appropriate for clinical use as a prognostic factor, and its predictive role in establishing oncotherapy can be also discussed.

[Role of the intraoperative electrical brain stimulation in conserving the speech and language function in neurosurgical procedures on conscious patients]. / Az intraoperatív elektromos agyi stimuláció szerepe a nyelvi és beszédfunkciók megorzése céljából éber betegeken végzett idegsebészeti beavatkozások során.

AIM OF THE STUDY: To summarize the results gained with awake craniotomies, which were performed in either low grade glioma patients or epilepsy surgical patients whose tumor or epileptogenic zone, was in the vicinity of eloquent, mostly language, cortices. PATIENT SELECTION AND METHODS: In our retrospective study we selected 16 patients who were operated awake between 1999-2011 at the Neurosurgical Department of MAV Kórház Budapest, or at the National Institute of Neurosciences in Budapest, or at the Neurosurgical Department of the University of Debrecen in Debrecen. In the presurgical evaluation if it was possible we performed functional magnetic resonance imaging, tractography and detailed neuropsychological testing. At the National Institute of Neurosciences all patients were operated with the aid of MR guided neuronavigation. RESULTS: Anesthesia was carried out without complications in all of the 16 cases. Monitoring of sleep deepness has significantly contributed to the safety of anesthesia during the superficial anesthezied states of the operation. The intraoperative neuropsychological tasks used for testing language were sensitive enough to judge the little disturbances in speech during stimulation. Stimulation evoked seizures could be adequately managed during surgery and did not influence the outcome of the procedures. The use of neuronavigation helped significantly by planning the optimal place for the craniotomy and by intraoperative orientation. CONCLUSIONS: Awake craniotomies require well practiced surgical teams, which requires the cooperation of neuro-anesthesiologits, neurosurgeons, neuropsychologist and electrophysiologists. It has two goals, first to reduce the time of surgery to minimize surgical complications, secondly the detailed intraoperative mapping of cognitive and motor functions to avoid any neurological deficit. The intraoperative anatomical data provided by the neuronavigation and the functional data provided by awake intraoperative stimulation of the patient together serve the safety of the patient which is essential in the neurologically minimal invasive neurosurgical approach of the 21st century.

Treatment Algorithm for Cancerous Wounds: A Systematic Review.

BACKGROUND: In advanced cancer stage the incidence of cancerous wounds is about 5%, and the estimated life expectancy is not more than 6 to 12 months. Without interdisciplinary and individualized treatment strategy, symptoms progress, and adversely influence quality of life. METHODS: Authors collected different treatment algorithms for cancerous wound published by wide scale of medical expertise, and summarized surgical, oncological, radiation oncological, nursing and palliative care aspects based on radiological information. RESULTS: Interdisciplinary approach with continuous consultation between various specialists can solve or ease the hopeless cases. CONCLUSIONS: This distressing condition needs a comprehensive treatment solution to alleviate severe symptoms. Non-healing fungating wounds without effective therapy are severe socio-economic burden for all participants, including patients, caregivers, and health services. In this paper authors collected recommendations for further guideline that is essential in the near future.

Clinical parameters predict the effect of bilateral subthalamic stimulation on dynamic balance parameters during gait in Parkinson's disease.

We investigated the effect of deep brain stimulation on dynamic balance during gait in Parkinson's disease with motion sensor measurements and predicted their values from disease-related factors. We recruited twenty patients with Parkinson's disease treated with bilateral subthalamic stimulation for at least 12 months and 24 healthy controls. Six monitors with three-dimensional gyroscopes and accelerometers were placed on the chest, the lumbar region, the two wrists, and the shins. Patients performed the instrumented Timed Up and Go test in stimulation OFF, stimulation ON, and right- and left-sided stimulation ON conditions. Gait parameters and dynamic balance parameters such as double support, peak turn velocity, and the trunk's range of motion and velocity in three dimensions were analyzed. Age, disease duration, the time elapsed after implantation, the Hoehn-Yahr stage before and after the operation, the levodopa, and stimulation responsiveness were reported. We individually calculated the distance values of stimulation locations from the subthalamic motor center in three dimensions. Sway values of static balance were collected. We compared the gait parameters in the OFF and stimulation ON states and controls. With cluster analysis and a machine-learning-based multiple regression method, we explored the predictive clinical factors for each dynamic balance parameter (with age as a confounder). The arm movements improved the most among gait parameters due to stimulation and the horizontal and sagittal trunk movements. Double support did not change after switching on the stimulation on the group level and did not differ from control values. Individual changes in double support and horizontal range of trunk motion due to stimulation could be predicted from the most disease-related factors and the severity of the disease; the latter also from the stimulation-related changes in the static balance parameters. Physiotherapy should focus on double support and horizontal trunk movements when treating patients with subthalamic deep brain stimulation.

Full Body Surface Coverage with Water-Equivalent Bolus as Novel Technique for Total Body Irradiation before Hematopoietic Stem Cell Transplantation in Pediatric Acute Lymphoid Leukemia.

BACKGROUND: Total body irradiation (TBI) 2 × 2 Gy for 3 consecutive days followed by chemotherapy for conditioning pediatric patients with acute lymphoid leukemia (ALL) before bone marrow transplantation is superior to chemo-conditioning alone. The globally used anterior-posterior/posterior-anterior (AP/PA) technique is the most referable method, but volumetric modulated arc therapy (VMAT) with modern linear accelerators is more precise in terms of ensuring better dose distribution, especially for skin, and higher protection of organs at risk, resulting in less side effects. METHOD: For TBI, a modern VMAT technique was used. Whole-body immobilization in the supine position was performed using a vacuum mattress with a full body coverage, with a water-equivalent bolus of 1 cm thickness. The design goal was to achieve dose inhomogeneity of less than ±10%. RESULTS: From 2020 to 2022, we performed TBI for five pediatric patients with ALL, with full body bolus and VMAT, who later received hematopoietic stem cell transplantation. No acute complications related to TBI were observed during the treatment period with a median follow-up of 1.27 (0.43-2.11) years. CONCLUSION: Using full body water-equivalent bolus with VMAT for TBI provides a safe method for children with a better organ sparing in the short term follow-up.

Factors affecting postural instability after more than one-year bilateral subthalamic stimulation in Parkinson's disease: A cross-sectional study.

BACKGROUND: Balance impairment in Parkinson's disease is multifactorial and its changes due to subthalamic stimulation vary in different studies. OBJECTIVE: We aimed to analyze the combination of predictive clinical factors of balance impairment in patients with Parkinson's disease treated with bilateral subthalamic stimulation for at least one year. METHODS: We recruited 24 patients with Parkinson's disease treated with bilateral subthalamic stimulation and 24 healthy controls. They wore an Opal monitor (APDM Inc.) consisting of three-dimensional gyroscopes and accelerometers in the lumbar region. We investigated four stimulation conditions (bilateral stimulation OFF, bilateral stimulation ON, and unilateral right- and left-sided stimulation ON) with four tests: stance on a plain ground with eyes open and closed, stance on a foam platform with eyes open and closed. Age, disease duration, the time elapsed after implantation, levodopa, and stimulation responsiveness were analyzed. The distance of stimulation location from the subthalamic motor center was calculated individually in each plane of the three dimensions. We analyzed the sway values in the four stimulation conditions in the patient group and compared them with the control values. We explored factor combinations (with age as confounder) in the patient group predictive for imbalance with cluster analysis and a machine-learning-based multiple regression method. RESULTS: Sway combined from the four tasks did not differ in the patients and controls on a group level. The combination of the disease duration, the preoperative levodopa responsiveness, and the stimulation responsiveness predicted individual stimulation-induced static imbalance. The more affected patients had more severe motor symptoms; primarily, the proprioceptive followed by visual sensory feedback loss provoked imbalance in them when switching on the stimulation. CONCLUSIONS: The duration of the disease, the severity of motor symptoms, the levodopa responsiveness, and additional sensory deficits should be carefully considered during preoperative evaluation to predict subthalamic stimulation-induced imbalance in Parkinson's disease.

Frequency-specific network activity predicts bradykinesia severity in Parkinson's disease.

OBJECTIVE: Bradykinesia has been associated with beta and gamma band interactions in the basal ganglia-thalamo-cortical circuit in Parkinson's disease. In this present cross-sectional study, we aimed to search for neural networks with electroencephalography whose frequency-specific actions may predict bradykinesia. METHODS: Twenty Parkinsonian patients treated with bilateral subthalamic stimulation were first prescreened while we selected four levels of contralateral stimulation (0: OFF, 1-3: decreasing symptoms to ON state) individually, based on kinematics. In the screening period, we performed 64-channel electroencephalography measurements simultaneously with electromyography and motion detection during a resting state, finger tapping, hand grasping tasks, and pronation-supination of the arm, with the four levels of contralateral stimulation. We analyzed spectral power at the low (13-20 Hz) and high (21-30 Hz) beta frequency bands and low (31-60 Hz) and high (61-100 Hz) gamma frequency bands using the dynamic imaging of coherent sources. Structural equation modelling estimated causal relationships between the slope of changes in network beta and gamma activities and the slope of changes in bradykinesia measures. RESULTS: Activity in different subnetworks, including predominantly the primary motor and premotor cortex, the subthalamic nucleus predicted the slopes in amplitude and speed while switching between stimulation levels. These subnetwork dynamics on their preferred frequencies predicted distinct types and parameters of the movement only on the contralateral side. DISCUSSION: Concurrent subnetworks affected in bradykinesia and their activity changes in the different frequency bands are specific to the type and parameters of the movement; and the primary motor and premotor cortex are common nodes.

Intraoperative electrophysiology in children - Single institute experience of 96 examinations.

AIM: To summarize our experience gathered during the use of different intraoperative electrophysiological modalities in children. MATERIALS AND METHODS: We analyzed the data collected from 96 pediatric neurosurgical interventions. During the operations, we used a combination of intraoperative electrophysiological examinations tailored to the actual pathologies. The modalities included cortical and white matter mapping, cranial nerve and cranial nerve nucleus stimulation, motor evoked potential (MEP), somatosensory evoked potential (SSEP), peripheral nerve stimulation, bulbocavernosus reflex, and a special setup for selective dorsal rhizotomy. RESULTS: The success ratio of the different modalities varied between 25% and 100%. All the applied methods could be used in children. CONCLUSION: Although the application of certain intraoperative techniques could be limited due to the ongoing developmental and maturation processes in childhood, we can not exclude the possibility of successful recording in any modality. Thus, we recommend to apply all the available methods in children bearing in mind that the success ratio might be lower than that in the adult population.

Quality Control of Portal Imaging with PTW EPID QC PHANTOM.

PURPOSE: Quality assurance (QA) and quality control (QC) of different electronic portal imaging devices (EPID) and portal images with the PTW EPID QC PHANTOM. MATERIAL AND METHODS: Characteristic properties of images of different file formats were measured on Siemens OptiVue500aSi, Siemens BeamView Plus, Elekta iView, and Varian PortalVision and analyzed with the epidSoft 2.0 program in four radiation therapy centers. The portal images were taken with Kodak X-OMAT V and the Kodak Portal Localisation ReadyPack films and evaluated with the same program. RESULTS: The optimal exposition both for EPIDs and portal films of different kind was determined. For double exposition, the 2+1 MU values can be recommended in the case of Siemens OptiVue500aSi Elekta iView and Kodak Portal Localisation ReadyPack films, while for Siemens BeamView Plus, Varian PortalVision and Kodak X-OMAT V film 7+7 MU is recommended. CONCLUSION: The PTW EPID QC PHANTOM can be used not only for amorphous silicon EPIDs but also for images taken with a video-based system or by using an ionization chamber matrix or for portal film. For analysis of QC tests, a standardized format (used at the acceptance test) should be applied, as the results are dependent on the file format used.

Polarized light and oviposition site selection in the yellow fever mosquito: no evidence for positive polarotaxis in Aedes aegypti.

Aquatic insects and insects associated with water use horizontally polarized light (i.e., positive polarotaxis) to detect potential aquatic or moist oviposition sites. Mosquitoes lay their eggs onto wet substrata, in water, water-filled tree/rock holes, or man-made small containers/bottles/old tyres containing water. Until now it has remained unknown whether mosquitoes are polarotactic or not. The knowledge how mosquitoes locate water would be important to develop new control measures against them. Thus, we studied in dual-choice laboratory experiments the role of horizontally polarized light in the selection of oviposition sites in blood-fed, gravid females of the yellow fever mosquito, Aedes aegypti. On the basis of our results we propose that Ae. aegypti is not polarotactic. Thus the yellow fever mosquito is the first known water-associated insect species that does not detect water by means of the horizontally polarized water-reflected light. This can be explained by the reflection-polarization characteristics of small-volume water-filled cavities/containers preferred by Ae. aegypti as oviposition sites.

[Approaches to individual radiotherapy in breast cancer: individual risk estimation and individualized techniques]. / Törekvés a sugárterápia individualizálására emlorákban: egyéni rizikóbecslés és egyénileg alkalmazott technikák.

INTRODUCTION: Radiotherapy comprises an integral part of the curative therapy of breast cancer by improving the locoregional control and survival when given on an individualized basis. Conformal radiotherapy and three-dimensional radiation treatment planning enhance the safety of radiotherapy by adjusting the irradiated volume to the shape of the target volume, and providing control of the radiation dose to the organs at risk (OARs). PATIENTS AND METHODS: The methods introduced at the authors' institute in 2002 are demonstrated. The breast/chest wall and lymph node areas were irradiated provided that there was a minimum risk of local or locoregional relapse of 10%. CT-based 3D radiotherapy treatment planning and individual patient-positioning were applied, with thermoplastic mask-fixation in the second part of the study. The dose constraints of the OARs were given in accordance with the literature recommendations. In the first group of patients, individually shaped blocks, in the second group, multileaf collimator, and in the third group, with the aim of a more homogenous dose-distribution in the target volume, intensity-modulated beams were applied. RESULTS: During the study, 737 breast cancer patients received conformal radiotherapy based on individual risk estimation. In 372 cases only local, while in 365 cases locoregional radiotherapy was delivered. The dose-homogeneity in the target volume was significantly improved in the second period of the study, when segments were superposed on the radiotherapy fields. The proportions of the target volumes irradiated with +/-10% of the planned dose in the breast/chest wall, axillary and supraclavicular lymph nodes and internal mammary lymph nodes varied between 90.5-94.2%, 84.1-93.8% and 86.7-91.6%, respectively, depending on the radiation technique used. The parameters indicating the dose to the ipsilateral lung or to the heart were significantly higher when locoregional radiotherapy was applied compared to that in case of local radiotherapy. Radiation dose to the ipsilateral lung and the heart was significantly reduced in the second part of the study when locoregional, but not when local radiotherapy was delivered. The introduction of individual immobilization by means of thermoplastic mask-fixation resulted in a relevant decrease in the uncertainty due to breathing motion and daily positioning errors, and also in a significant reduction of the dose to the contralateral breast. CONCLUSIONS: Adjuvant radiotherapy should be based on individual risk-benefit features. The need of the introduction of special techniques may be decided after the dose-volume analysis of the conformal radiotherapy plan based on 3D radiation treatment planning.

l-Alpha Glycerylphosphorylcholine as a Potential Radioprotective Agent in Zebrafish Embryo Model.

This work establishes the zebrafish embryo model for ionizing radiation (IR) modifier research and also evaluates the protective effect of l-alpha glycerylphosphorylcholine (GPC). Embryos were exposed to a single-fraction whole-body gamma irradiation (5, 10, 15, and 20 Gy) at different postfertilization time points and were serially assessed for viability and macro- and micromorphologic abnormalities. After toxicity evaluation, 194 µM of GPC was added for certain groups with 3-h incubation before the radiation. Nuclear factor kappa B (NF-κB) and interleukin-1ß (IL-1ß) expression changes were measured using quantitative real-time polymerase chain reaction. A higher sensitivity could be observed at earlier stages of the embryogenesis. The lethal dose (LD50) for 6 hours postfertilization (hpf) embryos was 15 Gy and for 24 hpf was 20 Gy on day 7, respectively. GPC administration resulted in a significant improvement in both the distortion rate and survival of the 24 hpf embryos. Qualitative evaluation of the histological changes confirmed the protective effect of GPC. IL-1ß and NF-κB overexpression due to 10 Gy irradiation was also reduced by GPC. GPC exhibited promising radioprotective effects in our zebrafish embryo model, decreasing the irradiation-induced morphological damage and lethality with significant reduction of IR-caused pro-inflammatory activation.

Partial breast radiotherapy with simple teletherapy techniques.

A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p < 0.001) with >90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.