Efficacy and Safety Analysis of Multislice Spiral CT-Guided Transthoracic Lung Biopsy in the Diagnosis of Pulmonary Nodules of Different Sizes.

Objective: This study is aimed at investigating the efficacy and safety of multislice spiral CT-guided transthoracic lung biopsy in the diagnosis of pulmonary nodules of different sizes. Methods: Data of 78 patients with pulmonary nodules who underwent CT-guided transthoracic lung biopsy in our hospital from January 2020 to December 2021 were retrospectively analyzed, and they were divided into the small nodules group (n = 12), medium nodules group (n = 35), and large nodules group (n = 31) according to the diameter of pulmonary nodules. The results of puncture biopsy and final diagnosis of pulmonary nodules of different sizes were compared. The incidence of complications in patients with pulmonary nodules of different sizes was compared. Univariate analysis was used to compare the incidence of complications in 78 patients. Logistic multiple regression analysis was used to analyze the independent risk factors of pneumothorax in patients with pulmonary nodule puncture. Logistic multiple regression analysis was used to analyze the independent risk factors of pulmonary hemorrhage in patients with pulmonary nodule puncture. Results: The diagnostic accuracy, sensitivity, and specificity were 83.33%, 100.00%, and 77.78% in small nodules group. The diagnostic accuracy, sensitivity, and specificity of medium nodules group were 85.71%, 100.00%, and 73.68%, respectively. The diagnostic accuracy, sensitivity, and specificity of large nodules group were 93.55%, 100.00%, and 33.33%, respectively. There was no significant difference in the incidence of pneumothorax among the three groups (P > 0.05). The incidence of pulmonary hemorrhage in small nodule group was higher than that in the medium nodule group and large nodule group, and the difference was statistically significant (P < 0.05). There was no significant difference in the incidence of total complications among the three groups (P > 0.05). There were statistically significant differences in clinical data such as the needle tract length, the puncture position, and the distance of the puncture needle passing through the lung tissue in patients with or without pneumothorax (P < 0.05). There were statistically significant differences in needle tract length, distance of puncture needle passing through lung tissue, and size of pulmonary nodules in patients with or without pulmonary hemorrhage (P > 0.05). Logistic multivariate analysis showed that needle tract length ≤ 50 mm, lateral decubitus position, and the distance of puncture needle passing through lung tissue ≥ 14 mm were independent risk factors for pneumothorax after puncture in patients with pulmonary nodules (P < 0.05). The needle tract length > 50 mm, the distance of puncture needle passing through lung tissue ≥ 14 mm, and small nodules (pulmonary nodules diameter ≤ 10 mm) were independent risk factors for pulmonary hemorrhage after puncture in patients with pulmonary nodules (P < 0.05). Conclusion: Multislice spiral CT-guided transthoracic lung biopsy is effective in diagnosing pulmonary nodules of different sizes.

Spiral Computed Tomography in the Quantitative Measurement of the Adjacent Structure of the Left Atrial Appendage in Patients with Atrial Fibrillation.

Cardiac arrhythmias are common clinical cardiovascular diseases. Arrhythmias are abnormalities in the frequency, rhythm, site of origin, conduction velocity, or sequence of excitation of the cardiac impulses. Arrhythmia mechanisms include foldback, altered autonomic rhythm, and triggering mechanisms. It can cause palpitations, dizziness, black dawn, syncope, and angina pectoris and can worsen a preexisting cardiac disease, reduce the quality of life, and increase mortality. Also, by making it one of the constant challenges for the clinical cardiovascular physician, we can get more information. The study included 94 patients with atrial fibers, including 56 men and 38 women aged 57, 46, 11, and 68 years. There are 80 patients with nonatrial fibers, including 44 men and 36 women aged 56, 10, and 83 years. Those who can perform a normal coronary angiography and exclude congenital heart disease, heart valve disease, and other cardiovascular diseases. In both groups, a 256-layer spiral CT examination was performed. A pulmonary vein scanning protocol was applied to the patients with atrial fibrillation, and this can perform normal coronary angiography and exclude those with cardiovascular diseases such as congenital heart disease and valvular heart disease. The purpose of this study is to investigate the anatomical changes of the left atrium and its adjacent structures by applying the 256 nm spiral CT imaging to visualize the left atrium and its adjacent structures and by applying the MPR technology, VR technology, and simulation endoscope techniques.

Diagnostic accuracy and associated complications of percutaneous computed tomography guided core needle biopsy of pulmonary lesions using coaxial technique.

This study was conducted to determine the diagnostic accuracy of CT-guided core needle biopsy (CNB) using coaxial technique of pulmonary lesions, its complications and factors affecting them. A total of 122 patients with suspected lung malignancy underwent CT-guided CNB. Final diagnosis was confirmed by histopathology. There were 84 (89.4%) true positive while 26 (92.9%) true negative cases. Diagnostic accuracy, sensitivity, specificity, PPV, NPV, and overall diagnostic accuracy were 97.67%, 72.22%, 89.36%, 92.86% and 90.16% respectively. Pneumothorax was the only complication observed in 10 (8.2%) patients. The odds of pneumothorax was found to be 10.72 times higher among patients with 2.5cm of size of lesions (AOR 10.72, 95% CI 1.49-76.77) while 86% lower among patients having prone position (AOR 0.14, 95% CI 0.021-0.96). Results indicate that percutaneous CT guided biopsy of pulmonary lesions using coaxial technique is a safe procedure with a high diagnostic accuracy and lesser risk of major complications.

Comparison of sequential and high-pitch-spiral coronary CT-angiography: image quality and radiation exposure.

New protocols for coronary computed tomography angiography (CCTA) could lower the radiation dose for patients but influence the image quality. To compare image quality and radiation exposure in step-and-shoot CCTA and high-pitch spiral CCTA. Fifty-nine pairs of patients matched for weight, height, sex and heart rate were included in this study (74 m, 44 f, average age 60 years, age range 29-94 years). Step-and-shoot CCTA and high-pitch spiral CCTA was performed on a third generation dual-source CT in equally sized patient groups. The signal-to-noise ratio (SNR) in the ascending aorta and the coronary arteries were determined for each dataset. Image quality was rated using a five-point scale. We used the t-test for paired samples to compare SNR and effective dose, and the Wilcoxon test to compare image quality scores. Mean effective dose for the step-and-shoot protocol (4.15 ± 3.07 mSv) was significantly higher in comparison to the high-pitch spiral protocol (1.2 ± 0.69 mSv; p < 0.0001). Mean SNR was higher with the step-and-shoot protocol compared to the high-pitch spiral protocol in the aorta, in the left main and peripheral coronary arteries (p < 0.01), in the proximal right coronary artery (p = 0.027). Image quality scores were significantly better for the step-and-shoot protocol (p = 0.0003). Step-and-shoot CCTA has significantly better SNR and overall image quality compared to high-pitch spiral CCTA, but with a mean effective dose more than thrice as high.

Skin toxicity after chest wall/breast plus level III-IV lymph nodes treatment with helical tomotherapy.

INTRODUCTION: To evaluate the incidence of toxicity in breast cancer with helical tomotherapy (HT). MATERIALS AND METHODS: 51 patients with breast cancer were assigned to postoperative radiotherapy by means of HT to the chest wall/breast plus draining nodes. During HT treatment, toxicity was monitored and were assessed using the Common Terminology Criteria for Adverse Events 4.0 scale. RESULTS: Acute skin G3 toxicity observed in 1.9% cases. No acute or late G4 toxicity was observed. At a median follow-up of 21 months 2 patients have late G1 toxicity. CONCLUSIONS: HT was associated with a low incidence of low-grade skin toxicity.

Case report of dependent venous contrast pooling and layering in a patient without acute cardiogenic shock.

RATIONALE: We present a case of incidental venous contrast pooling and layering in a patient without sudden cardiac arrest or cardiogenic shock. PATIENT CONCERNS: The patient presented with only discrete symptoms and did not suffer fatal cessation of the cardiac pump function during or shortly after the scan. DIAGNOSIS: The patient showed stigmata of venous gravity-dependent pooling and layering of contrast medium, which has frequently been described as a sign of imminent cardiogenic shock and cardiac arrest. INTERVENTIONS: A cardiologic consultation including echocardiography was initiated. OUTCOMES: Echocardiography confirmed valvular heart disease and biventricular heart failure. A subsequent follow-up CT acquired 8 months after the incidental finding showed no signs of dependent contrast pooling. LESSONS: Pooling and layering of contrast medium can occur in patients not suffering acute fatal cessation of the cardiac pump function. Nonetheless, any signs of venous pooling observed in CT examinations, especially gravity-dependent layering of contrast medium, are indicative of severe heart dysfunction and should prompt immediate cardio-pulmonary monitoring and increased level of medical care.

High-pitch versus sequential mode for coronary calcium in individuals with a high heart rate: Potential for dose reduction.

BACKGROUND: To determine the impact of high-pitch spiral acquisition on radiation dose and cardiovascular disease (CVD) risk stratification by coronary artery calcium (CAC) assessment with computed tomography in individuals with a high heart rate. METHODS: Of the ROBINSCA trial, 1990 participants with regular rhythm and heart rates >65 beats per minute (bpm) were included. As reference, 390 participants with regular heart rates ≤65 bpm were used. All participants underwent prospectively electrocardiographically(ECG)-triggered imaging of the coronary arteries using dual source CT at 120 kVp, 80 ref mAs using both high-pitch spiral mode and sequential mode. Radiation dose, Agatston score, number of positive scores, as well as median absolute difference of the Agatston score were determined and participants were stratified into CVD risk categories. RESULTS: A similar percentage of participants with low heart rates and high heart rates had a positive CAC score in data sets acquired in high-pitch spiral (low heart rate: 57.7%, high heart rate: 55.8%) and sequential mode (58.0%, 54.7%, p = n.s.). The median absolute difference in Agatston scores between acquisition modes was 14.2% and 9.2%, for the high and low heart rate groups, respectively. Excellent agreement for risk categorization between the two data acquisition modes was found for the high (κ = 0.927) and low (κ = 0.946) heart rate groups. Radiation dose was 48% lower for high-pitch spiral versus sequential acquisitions. CONCLUSION: Radiation dose for the quantification of coronary calcium can be reduced by 48% when using the high-pitch spiral acquisition mode compared to the sequential mode in participants with a regular high heart rate. CVD risk stratification agreement between the two modes of data acquisition is excellent.

Feasibility of Respiratory-gated High-pitch Spiral CT:: Free-breathing Inspiratory Image Quality.

RATIONALE AND OBJECTIVES: This study aimed to develop and implement a respiratory-gated setup for dual-source computed tomography (CT) at high pitch to examine patients in a reproducible inspiratory phase. MATERIALS AND METHODS: Twenty-one patients underwent free-breathing respiratory-gated chest CT using a high-pitch scan mode no more than 6 months after inspiratory breath-held nongated CT, which serves as reference. Scan parameters were as follows: pitch = 3.4, 128 × 0.6 mm collimation, 0.28 s gantry rotation time, and 150 ref.mAs per tube at 120 kV. The examinations were triggered using the tidal wave provided by a respiratory-gating system as input signal. Image quality was assessed focusing on artifacts and delineation of the anatomical and pathological structures. Lung volumes were measured on both free-breathing and reference examinations. RESULTS: All examinations were performed without complications. Image quality was high with both protocols. Significantly less motion artifacts were recorded with the high-pitch mode compared to the reference (P = 0.02). Most of the artifacts were located in the peripheral parts of the lower lobes for the study group and in the central part of the left lower lobe for the reference. Average total lung volume was 4.5 ± 1.5 L in respiratory-gated examinations and 5.8 ± 0.9 L in examinations with breath-hold in inspiration. CONCLUSIONS: High-pitch chest CT scanning during free breathing minimizes motion artifacts, improving image quality in patients with limited breath-holding abilities. To assure scanning in an inspiratory phase, data acquisition should be triggered with a respiratory-gating system.

Estimated risk of radiation-induced cancer from paediatric chest CT: two-year cohort study.

BACKGROUND: The increasing absolute number of paediatric CT scans raises concern about the safety and efficacy and the effects of consecutive diagnostic ionising radiation. OBJECTIVE: To demonstrate a method to evaluate the lifetime attributable risk of cancer incidence/mortality due to a single low-dose helical chest CT in a two-year patient cohort. MATERIALS AND METHODS: A two-year cohort of 522 paediatric helical chest CT scans acquired using a dedicated low-dose protocol were analysed retrospectively. Patient-specific estimations of radiation doses were modelled using three different mathematical phantoms. Per-organ attributable cancer risk was then estimated using epidemiological models. Additional comparison was provided for naturally occurring risks. RESULTS: Total lifetime attributable risk of cancer incidence remains low for all age and sex categories, being highest in female neonates (0.34%). Summation of all cancer sites analysed raised the relative lifetime attributable risk of organ cancer incidence up to 3.6% in female neonates and 2.1% in male neonates. CONCLUSION: Using dedicated scan protocols, total lifetime attributable risk of cancer incidence and mortality for chest CT is estimated low for paediatric chest CT, being highest for female neonates.

Randomization to screening for prostate, lung, colorectal and ovarian cancers and thyroid cancer incidence in two large cancer screening trials.

BACKGROUND: Thyroid cancer incidence has increased significantly over the past three decades due, in part, to incidental detection. We examined the association between randomization to screening for lung, prostate, colorectal and/or ovarian cancers and thyroid cancer incidence in two large prospective randomized screening trials. METHODS: We assessed the association between randomization to low-dose helical CT scan versus chest x-ray for lung cancer screening and risk of thyroid cancer in the National Lung Screening Trial (NLST). In the Prostate Lung Colorectal and Ovarian Cancer Screening Trial (PLCO), we assessed the association between randomization to regular screening for said cancers versus usual medical care and thyroid cancer risk. Over a median 6 and 11 years of follow-up in NLST and PLCO, respectively, we identified 60 incident and 234 incident thyroid cancer cases. Cox proportional hazards regression was used to calculate the cause specific hazard ratios (HR) and 95% confidence intervals (CI) for thyroid cancer. RESULTS: In NLST, randomization to lung CT scan was associated with a non-significant increase in thyroid cancer risk (HR = 1.61; 95% CI: 0.96-2.71). This association was stronger during the first 3 years of follow-up, during which participants were actively screened (HR = 2.19; 95% CI: 1.07-4.47), but not subsequently (HR = 1.08; 95% CI: 0.49-2.37). In PLCO, randomization to cancer screening compared with usual care was associated with a significant decrease in thyroid cancer risk for men (HR = 0.61; 95% CI: 0.49-0.95) but not women (HR = 0.91; 95% CI: 0.66-1.26). Similar results were observed when restricting to papillary thyroid cancer in both NLST and PLCO. CONCLUSION: Our study suggests that certain medical encounters, such as those using low-dose helical CT scan for lung cancer screening, may increase the detection of incidental thyroid cancer.

Issues with implementing a high-quality lung cancer screening program.

After a comprehensive review of the evidence, the United States Preventive Services Task Force recently endorsed screening with low-dose computed tomography as an early detection approach that has the potential to significantly reduce deaths due to lung cancer. Prudent implementation of lung cancer screening as a high-quality preventive health service is a complex challenge. The clinical evaluation and management of high-risk cohorts in the absence of symptoms mandates an approach that differs significantly from that of symptom-detected lung cancer. As with other cancer screenings, it is essential to provide to informed at-risk individuals a safe, high-quality, cost-effective, and accessible service. In this review, the components of a successful screening program are discussed as we begin to disseminate lung cancer screening as a national resource to improve outcomes with this lethal cancer. This information about lung cancer screening will assist clinicians with communications about the potential benefits and harms of this service for high-risk individuals considering participation in the screening process.

Lesión del músculo pectoral por carcinoma lobulillar infiltrante / Pectoralis major muscle injure caused by infiltrating lobular carcinoma

Se presenta una paciente femenina de 69 años de edad, quien acudió en varias ocasiones al consultorio del médico de familia por notar aumento de volumen en la mama izquierda, considerado como resultado del efecto adverso a la ingestión de espironolactona. Se suspende el medicamento sin mejoría clínica. Se indicó ultrasonido de mama y se informa imagen de aspecto tumoral debajo del tejido mamario, que impresiona estar en relación con el músculo pectoral mayor; a esto se asocia una alteración del patrón mamario. Se realizó mamografía diagnóstica, se encuentra asimetría de volumen de la mama izquierda y una zona de aumento de la densidad cerca del pectoral, sin visualizar nódulo definido. Se realizó tomografía axial computarizada simple y contrastada. Se aprecia masa tumoral del músculo pectoral mayor izquierdo que infiltra tejido mamario y mediastino anterior, con diagnóstico imaginológico sugestivo de tumor del músculo pectoral mayor izquierdo. Se realizó biopsia por aguja fina de la lesión, guiada por ultrasonido y el diagnóstico fue carcinoma lobulillar infiltrante de mama. Se concluye que el comportamiento imaginológico puede estar relacionado con las pobres manifestaciones clínicas y, por tanto, con el diagnóstico tardío(AU)

The case of 69 years-old woman, who went several times to the family physician's office because of the increased volume of her left breast, was presented. This problem was considered to result from the adverse effect of the spironolactone intake. The drug consumption ceased but there was no clinical improvement. Breast ultrasound test was indicated in which a tumor-like image below the breast tissue was observed; it seemed to be related to the major pectoralis muscle, additionally, there was altered breast pattern. Diagnostic mammography was performed, asymmetric volume of the left breast was found together with an increased density area located near the pectoralis, without viewing a defined nodule. Simple and contrast computerized tomography were also performed. It was observed that there was tumor mass in the left pectoralis major muscle infiltrating into the breast tissue and the anterior mediastinum, with imaging diagnosis suggestive of left pectoralis major muscle tumor. Ultrasound-guided fine-needle biopsy of the lesion was applied and the resulting diagnosis was infiltrating lobular carcinoma of the breast. It was concluded that the imaging result could be related to poor clinical manifestations and thus, to late diagnosis(AU)

Normal tissue dose and second cancer risk due to megavoltage fan-beam CT, static tomotherapy and helical tomotherapy in breast radiotherapy.

This study investigates the dose from the 1mm collimator width megavoltage fan-beam CT (fine, normal and coarse pitch) available on tomotherapy as well as for whole-breast tomotherapy treatments. The BEIR VII lifetime attributable risk model was utilised to assess the significance of the imaging dose relative to the treatment dose.

Aspectos tomográficos da coluna cervical de equinos / Tomographic imaging of the cervical spine of horses

Descreveu-se a anatomia da região cervical de equinos adultos, com base em imagens obtidas no exame de tomografia computadorizada helicoidal realizado em peças anatômicas de equinos adultos. A tomografia computadorizada foi o método de imagem diagnóstica de escolha e possibilita as reconstruções de imagens tridimensionais e em outros planos anatômicos, como sagital e coronal. Todas as imagens foram adquiridas e avaliadas em filtro e janela para tecido ósseo. Observaram-se diferenças anatômicas e as particularidades normais das vértebras, principalmente da região occipitoatlantoaxial, a qual apresenta maior incidência de alterações.

The anatomy of the cervical spine of mature horses based on images obtained with a helical computed tomography examination performed on anatomic specimens was studied. Computed tomography was the diagnostic imaging method of choice and allowed three-dimensional reconstructions of images and other anatomical planes, such as coronal and sagittal. All images were acquired and evaluated in the filter and window to bone tissue. It was possible to demonstrate the anatomical differences and peculiarities of the normal vertebrae, particularly the occipito-atlantoaxial region, which has a higher incidence of changes to assist in the visualization of any change of the bone pattern on CT studies.

Absorbed radiation doses during tomographic examinations in dental implant planning: a study in humans.

OBJECTIVE: The aim of this human study was to evaluate the radiation doses in the buccal cavity and face, during panoramic, spiral conventional tomography, and helicoidal computerized tomography exams. MATERIAL AND METHODS: Lithium fluoride TL detectors (TLD-100) were placed on the skin at anatomic points such as parotid glands, submandibular glands, thyroid glands, and crystalline to assess the skin entrance dose in 19 patients who were to undergo dental implant surgery. RESULTS: In the panoramic exam, maximum doses were observed near the parotid glands at 1.57 (±18%) mGy on the right and 1.89 (±18%) mGy on the left. In the spiral conventional tomography exam, the maximum dose was 4.41 (±21%) mGy near the right and left parotid glands, whereas near the right or left submandibular glands, the maximum doses reached 40.7 (±18%) mGy. In the helicoidal computerized tomography for mandibular and maxilla exams, the maximum dose was 40.9 (±15%) mGy near the parotid glands and 41.0 (±18%) mGy near the submandibular glands. Near the thyroid and eye lens, doses were lower than 0.23 (±21%) in all exams. CONCLUSION: Regardless of the exam target area, the submandibular and parotid glands represented the most irradiated organs. This data suggests that efforts should be made by professionals to improve and optimize methods in order to reduce doses without losing the information necessary for treatment planning.

X-ray induced DNA double-strand breaks in coronary CT angiography: comparison of sequential, low-pitch helical and high-pitch helical data acquisition.

BACKGROUND: Aim of this study was to compare DNA double-strand breaks (DSBs) in blood lymphocytes of patients undergoing high-pitch helical, low-pitch helical and sequential coronary CT angiography. METHODS AND RESULTS: 66 patients were examined with various scan protocols and modes (low-pitch helical scan: 100-120 kV, 320-438 mAs/rot, pitch 0.18-0.39, with or without ECG-pulsing, n=35; prospectively ECG-triggered high-pitch helical scan: 100-120 kV, 320-456 mAs/rotation, pitch 3.2-3.4, n=19; prospectively ECG-triggered sequential scan: 100-120 kV, 150-300 mAs or 320-370 mAs/rotation, n=12) either using a 64-slice or 128-slice dual-source CT or a 128-slice single source CT scanner. Blood samples were obtained before and 30 min after CT and DSBs were analyzed in isolated lymphocytes using γ-H2AX immunofluorescence microscopy. A significant increase of DSBs was measurable 30 min after CTA (range 0.01-0.71/cell). CT induced DSBs showed a significant correlation with the estimated effective dose (ρ=0.90, p<0.00001). Both prospectively ECG-triggered sequential (0.10 DSBs/cell, 176 mGy cm, p<0.00001) and high-pitch helical scan protocols (0.03 DSBs/cell, 109 mGy cm, p<0.00001) led to a significant reduction of median DLP and DSB levels compared to low-pitch helical scans (0.34 DSBs/cell, 828 mGy cm). A reduction of the tube voltage resulted in significantly lower whereas additional calcium scoring resulted in elevated DLP and DNA damages (p<0.05 each). CONCLUSION: In coronary CTA, data acquisition protocols have a significant influence on the X-ray induced DSB levels. Using γ-H2AX immunofluorescence microscopy different scan modes in different CT generations can be compared concerning their biological impact.

Feasibility of helical tomotherapy for radical dose retreatment in pelvic area: a report of 4 cases.

AIMS AND BACKGROUND: To retrospectively determine acute toxicity and local control in patients with recurrence after definitive radiotherapy for prostate, bladder and rectal carcinoma. METHODS: Between September 2009 and March 2010, 4 patients with a prior history of pelvic radiotherapy were treated with helical tomotherapy. The prior course of radiotherapy was given for prostate cancer in 2 patients, bladder carcinoma in 1 patient and rectal carcinoma in 1 patient. The median prescribed dose of the prior course of radiotherapy was 6320 cGy (range, 5000-7600), and the median elapsed time between the first and second course was 17 months (range, 4-73). The total prescribed dose for tomotherapy retreatment was 60 Gy in 3 patients and 50 Gy in 1 patient. Hormone therapy was administered to 2 patients before and during radiation. No patient underwent surgical resection. RESULTS: The cumulative mean dose to the rectum ranged from 3813 to 6058 cGy; cumulative rectal maximum dose to 1 cc ranged from 6475 to 8780 cGy. Regarding the bladder, the cumulative mean dose was between 4384 and 7612 cGy; cumulative maximum dose to 1 cc ranged from 7560 to 9790 cGy. All patients completed the re-irradiation course. Acute genitourinary toxicity (RTOG scale) was grade 0 in 3 patients and grade 1 in 1 patient; acute gastrointestinal toxicity was grade 0 in 3 patients and grade 1 in 1 patient. With a median follow-up of 9 months (range, 7-12), late toxicity was G0 in all patients. Three patients showed partial response with computed tomography or magnetic resonance imaging, and 1 had a PSA decrease. CONCLUSIONS: Re-irradiation with helical tomotherapy was well tolerated, with low rates of acute and late toxicity. It can be therefore considered a useful tool to improve local control in patients previously treated with radiotherapy. However, a larger number of patients and a longer follow-up are required to assess retreatment safety.

Helical tomotherapy for meningiomas of the skull base and in paraspinal regions with complex anatomy and/or multiple lesions.

AIM: To evaluate helical tomotherapy for the treatment of complex-shaped uni- or multifocal meningiomas. METHODS AND MATERIALS: Between 2007 and 2009, 12 patients with complex-shaped meningiomas and/or multiple meningioma lesions were treated with helical tomotherapy. Histologic classification according to the most recent WHO classification for brain tumors was WHO grade I meningioma in 5 patients, atypical WHO grade II meningioma in 5 patients, and anaplastic WHO grade III meningioma in 2 patients. Eight patients were treated with primary radiotherapy, and in 4 patients tomotherapy was performed as re-irradiation for recurrent tumors. RESULTS: All patients were alive at the time of this analysis. Treatment was well tolerated by all patients. No severe side effects were observed. Four of 12 patients developed progression during follow-up at 2, 4, 17 and 29 months after radiotherapy. Of these, 2 patients were diagnosed with anaplastic meningiomas, and 2 patients suffered from atypical meningioma. Tumor progression developed after primary radiotherapy in 2 patients, and 2 recurrences developed after re-irradiation. CONCLUSIONS: Helical tomotherapy can help meet the challenge of treating complex-shaped meningiomas in critical locations with one or multiple lesions due to the excellent dose distributions and the favorable clinical results.