Dosimetric impact of switching from AAA to Acuros dose-to-water and dose-to-medium for RapidArc plans of nasopharyngeal carcinomas.

PURPOSE: This work aims to evaluate the dosimetric consequences of replacing the Anisotropic Analytical Algorithm (AAA) by Acuros XB (AXB), dose-to-water (Dw) or dose-to-medium (Dm), for RapidArc plans of nasopharyngeal carcinomas (NPC). MATERIALS AND METHODS: Seventeen NPC plans created with AAA (v15.6) were recalculated with AXB (v15.6) Dw and Dm. The dose-volume parameters to the planning target volumes (PTV) and relevant organs at risk (OAR) were compared. The high dose PTV was divided into bone, air and tissue components and the comparison was performed for each of them. RESULTS: AXB Dw revealed no significant differences in the PTVs compared to AAA. Lower values were observed to spinal cord, brainstem, oral cavity and parotids (0.5% to 2.3%), and higher values to cochleas (up to 5.4%) and mandible (up to 6.7%). AXB Dm predicted lower values than AAA for all PTVs and OARs (2.0% to 6.1%). For the bone PTV subvolume, AXB Dw and Dm predicted respectively higher (2.4%) and lower (2.2% to 3.4%) values. No significant differences were noted in air. AXB predicted lower values than AAA in soft tissues (0.4% to 1.6%). The largest difference was found to the mandible V60Gy parameter, with median differences of 6.7% for AXB Dw and -6.0% for AXB Dm. CONCLUSION: Significant dose differences are expected when switching from AAA to AXB in NPC cases. The dose prescriptions and the tolerance limits for some OARs, especially those of high density, may need to be adjusted depending on the selected dose calculation algorithm and reporting mode.

Collision prediction for intracranial stereotactic radiosurgery planning: An easy-to-implement analytical solution.

PURPOSE: Gantry collision is a concern in linac-based stereotactic radiosurgery (SRS). Without collision screening, the planner may compromise optimal planning, unnecessary re-planning delays can occur, and incomplete treatments may be delivered. To address these concerns, we developed a software for collision prediction based on simple machine measurements. MATERIALS AND METHODS: Three types of collision were identified; gantry-couch mount, gantry-couch and gantry-patient. Trigonometric formulas to calculate the distance from each potential point of collision to the gantry rotation axis were generated. For each point, collision occurs when that distance is greater than the gantry head to gantry rotational axis distance. The colliding arc for each point is calculated. A computer code incorporating these formulas was generated. The inputs required are the couch coordinates relative to the isocenter, the patient dimensions, and the presence or absence of a circular SRS collimator. The software outputs the collision-free gantry angles, and for each point, the shortest distance to the gantry or the colliding sector when collision is identified. The software was tested for accuracy on a TrueBEAM® machine equipped with BrainLab® accessories for 80 virtual isocenter-couch angle configurations with and without a circular collimator and a parallelepiped phantom. RESULTS: The software predicted the absence of collision for 19 configurations. The mean absolute error between the measured and predicted gantry angle of collision for the remaining 61 cases was 0.86 (0.01-2.49). CONCLUSION: This tool accurately predicted collisions for linac-based intracranial SRS and is easy to implement in any radiotherapy facility.

Carotid Artery Tortuosity Is Associated with Connective Tissue Diseases.

BACKGROUND AND PURPOSE: There is a general assumption in the cerebrovascular literature that there is an association between carotid artery tortuosity and connective tissues disease; however, this has not been firmly established. The purpose of this study was to determine the prevalence of carotid artery tortuosity in patients with connective tissue diseases relative to matched controls. MATERIALS AND METHODS: Patients with previous CTA or MRA and a diagnosis of connective tissue diseases were identified and compared with a cohort of age-matched controls. Radiologists blinded to the diagnosis reviewed the images and evaluated the presence of carotid artery tortuosity (including loops, kinks, or coils). Continuous variables were compared using the Student t test, and categoric variables with χ2 tests. RESULTS: One hundred forty-three patients with connective tissue disease and 143 controls were included in this study. Specific diagnoses included Marfan (n = 33), nonvascular Ehlers-Danlos (n = 36), Ehlers-Danlos vascular-type (n = 32), neurofibromatosis type 1 (n = 26), and Loeys-Dietz (n = 16) syndromes. The presence of carotid tortuosity was 44% in connective tissue disease and 16% in controls (P < .001). Of tortuosity manifestations, coils were most prevalent (23% versus 3%; P < .001). Among the various connective tissue diseases, the rates of any carotid tortuosity were 88% for Marfan syndrome, 63% for Loeys-Dietz syndrome, 42% for neurofibromatosis type 1, and 19% for both vascular- and nonvascular-type Ehlers-Danlos syndrome. The positive predictive value of the combination of aortic aneurysm and carotid tortuosity being associated with connective tissue disease was 95.4%. The specificity was 98.6%. CONCLUSIONS: Carotid artery tortuosity is highly associated with connective tissue diseases, particularly Marfan syndrome, Loeys-Dietz syndrome, and neurofibromatosis type 1. Such findings are relevant in risk assessment for vascular complications in connective tissue disease, endovascular treatment planning, and in understanding the pathomechanisms of vascular tortuosity in general.

Clinical and Imaging Characteristics of Diffuse Intracranial Dolichoectasia.

BACKGROUND AND PURPOSE: Among patients with vertebrobasilar dolichoectasia is a subset of patients with disease affecting the anterior circulation as well. We hypothesized that multivessel intracranial dolichoectasia may represent a distinct phenotype from single-territory vertebrobasilar dolichoectasia. The purpose of this study was to characterize clinical characteristics and angiographic features of this proposed distinct phenotype termed "diffuse intracranial dolichoectasia" and compare them with those in patients with isolated vertebrobasilar dolichoectasia. MATERIALS AND METHODS: We retrospectively reviewed a consecutive series of patients with diffuse intracranial dolichoectasia and compared their demographics, vascular risk factors, additional aneurysm prevalence, and clinical outcomes with a group of patients with vertebrobasilar dolichoectasia. "Diffuse intracranial dolichoectasia" was defined as aneurysmal dilation of entire vascular segments involving ≥2 intracranial vascular beds. Categoric and continuous variables were compared by using χ2 and Student t tests, respectively. RESULTS: Twenty-five patients had diffuse intracranial dolichoectasia, and 139 had vertebrobasilar dolichoectasia. Patients with diffuse intracranial dolichoectasia were older than those with vertebrobasilar dolichoectasia (70.9 ± 14.2 years versus 60.4 ± 12.5 years, P = .0002) and had a higher prevalence of abdominal aortic aneurysms (62.5% versus 14.3%, P = .01), other visceral aneurysms (25.0% versus 0%, P < .0001), and smoking (68.0% versus 15.9%, P < .0001). Patients with diffuse intracranial dolichoectasia were more likely to have aneurysm growth (46.2% versus 21.5%, P = .09) and rupture (20% versus 3.5%, P = .007) at follow-up. Patients with diffuse intracranial dolichoectasia were less likely to have good neurologic function at follow-up (24.0% versus 57.6%, P = .004) and were more likely to have aneurysm-related death (24.0% versus 7.2%, P = .02). CONCLUSIONS: The natural history of patients with diffuse intracranial dolichoectasia is significantly worse than that in those with isolated vertebrobasilar dolichoectasia. Many patients with diffuse intracranial dolichoectasia had additional saccular and abdominal aortic aneurysms. These findings suggest that diffuse intracranial dolichoectasia may be a distinct vascular phenotype secondary to a systemic arteriopathy affecting multiple vascular beds.

Intracranial and Extracranial Neurovascular Manifestations of Takayasu Arteritis.

BACKGROUND AND PURPOSE: Takayasu arteritis is a rare, large-vessel vasculitis that presents with symptoms related to end-organ ischemia. While the extracranial neurovascular manifestations of Takayasu arteritis are well-established, little is known regarding the intracranial manifestations. In this study, we characterize the intracranial and cervical neurovascular radiologic findings in patients with Takayasu arteritis. MATERIALS AND METHODS: Patients with Takayasu arteritis who presented to our institution between 2001 and 2016 with intracranial and/or cervical vascular imaging were included in this study. Images were evaluated for the presence of vascular abnormalities, including intracranial or extracranial stenosis, vessel-wall thickening, dissection, subclavian steal, aneurysms, infarcts, and hemorrhages. Descriptive analyses are reported. RESULTS: Seventy-nine patients with Takayasu arteritis met the criteria for inclusion in this study. The most common presenting neurologic symptoms were headache (32.9%) and dizziness (15.2%). Intracranial and extracranial vascular imaging was performed in 84.8% and 89.9% of patients, respectively. Among patients with intracranial vascular imaging, 3 (3.9%) had intracranial aneurysms, 3 (3.9%) had acute large-vessel occlusion, 6 (7.6%) had intracranial vasculitis, and 1 (1.3%) had reversible cerebrovascular constriction syndrome. Among patients with cervical vascular imaging, 42 (53.1%) had some degree of narrowing of the common carotid artery and 18 (22.8%) had narrowing of the ICAs. Seventeen patients (23.6%) had subclavian steal. CONCLUSIONS: Intracranial vascular abnormalities in patients with Takayasu arteritis presenting with neurologic symptoms are not rare, with cerebral vasculitis seen in 7.8% of patients, and stroke secondary to large-vessel occlusion, in 3.9% of patients. Cervical vascular manifestations of Takayasu arteritis were present in most patients in our study.

Clinical Outcomes of Patients with Delayed Diagnosis of Spinal Dural Arteriovenous Fistulas.

BACKGROUND AND PURPOSE: Spinal dural arteriovenous fistulas are commonly missed on imaging or misdiagnosed as inflammatory or neoplastic processes. We reviewed a consecutive series of spinal dural arteriovenous fistulas referred to our institution that were missed or misdiagnosed on initial imaging and studied the clinical consequences of missing or misdiagnosing the lesion. MATERIALS AND METHODS: We reviewed spinal dural arteriovenous fistulas diagnosed at our institution between January 1, 2000, and November 1, 2014. A lesion was defined as "misdiagnosed" if initial MR imaging or CT myelography demonstrated characteristic imaging features of spinal dural arteriovenous fistula but the patient was clinically or radiologically misdiagnosed. Outcomes included length of delay of diagnosis, increased disability (increase in mRS or Aminoff motor disability of ≥1 point) between initial imaging evaluation and diagnosis date, and posttreatment disability. RESULTS: Fifty-three consecutive spinal dural arteriovenous fistulas that were initially misdiagnosed despite having characteristic imaging findings on MR imaging or CT myelography were included in our study. Eight patients (18.9%) underwent spinal angiography before referral, which was interpreted as having negative findings but was either incomplete (6 cases) or retrospectively demonstrated the spinal dural arteriovenous fistulas (2 cases). The median time of delayed diagnosis was 6 months (interquartile range, 2-14 months). Fifty-one patients (96.2%) had increased disability between the initial study, which demonstrated features of a spinal dural arteriovenous fistula, and diagnosis. Thirty-two patients (60.4%) developed a new requirement for a walker or wheelchair. Following treatment, 21 patients (41.2%) had an improvement of 1 point on the mRS or Aminoff motor disability scale. CONCLUSIONS: Delayed diagnosis of spinal dural arteriovenous fistula with characteristic imaging features results in high rates of additional disability that are often irreversible despite surgical or endovascular treatment of the fistula.

Mortality in cerebral venous thrombosis: results from the national inpatient sample database.

BACKGROUND: Outcomes of cerebral venous thrombosis (CVT) vary from full recovery to death. Few studies have been performed examining epidemiologic and medical risk factors associated with high mortality in CVT. In this study, we examined the National Inpatient Sample (NIS) to determine the epidemiologic and medical risk factors associated with increased mortality from CVT. MATERIALS AND METHODS: Using the NIS from 2001 to 2008, patients who suffered from CVT were identified using the ICD-9 codes 437.6 (nonpyogenic thrombosis of intracranial venous sinus), 325 (phlebitis and thrombophlebitis of intracranial venous sinuses) and 671.5 (peripartum phlebitis and thrombosis, cerebral venous thrombosis, thrombosis of intracranial venous sinus). We analyzed the associations of demographic factors, risk factors, comorbidities, complications of CVT, and therapeutic interventions with in-hospital mortality. We performed a multivariate logistic regression analysis to determine which variables were independently associated with in-hospital mortality. RESULTS: 11,400 patients were hospitalized with CVT between 2001 and 2008. Two-hundred and thirty-two (2.0%) suffered in-hospital mortality. Patients 15-49 years old had the lowest mortality rate (1.5%) compared with 2.8% for patients aged 50-64 (p < 0.001) and 6.1% for patients ≥65 years old (p < 0.001). The most common condition associated with CVT was pregnancy/puerperium (24.6%), and these women had a low mortality rate (0.4%). On multivariate analysis, the comorbidity most strongly associated with increased risk of mortality was sepsis (mortality rate 15.6%, OR = 7.5, 95% CI = 4.79-11.53, p < 0.001). Malignancy, underlying autoimmune disease and substance abuse were also independently associated with mortality, but with lower mortality rates (<5%). Complications associated with increased risk of mortality included paralysis (8.0%, OR = 3.4, 95% CI = 3.17-6.96, p < 0.001), intracranial hemorrhage (8.7%, OR = 5.4, 95% CI = 4.38-7.96, p < 0.001), and hydrocephalus (15.0%, OR = 3.2, 95% CI = 5.54-15.11, p = 0.004). Demographic variables associated with decreased mortality on multivariate analysis were male gender (2.1%, OR = 0.62, 95% CI = 0.43-0.87, p = 0.006) and Asian/Pacific Islander race (OR = 0.00, 95% CI = 0-0.27, p < 001). CONCLUSIONS: CVT is associated with a low in-hospital mortality rate. Amongst patients suffering CVT, male gender and Asian/Pacific Islander race were independently associated with lower odds of in-hospital mortality when compared to their female and white counterparts, respectively. Septic patients with CVT have the greatest risk of in-hospital mortality. Hydrocephalus, intracranial hemorrhage, and motor deficits are also associated with higher risk of death. Our results build on previous evidence that serves to define a group of patients with CVT at high risk of early death.

Better outcomes with treatment by coiling relative to clipping of unruptured intracranial aneurysms in the United States, 2001-2008.

BACKGROUND AND PURPOSE: Endovascular therapy has increasingly become an acceptable option for treatment of unruptured aneurysms. To better understand the recent trends in the use of and outcomes related to coiling compared with clipping for unruptured aneurysms in the United States, we evaluated the NIS. MATERIALS AND METHODS: Hospitalizations for clipping or coiling of unruptured cerebral aneurysms from 2001 to 2008 were identified by cross-matching ICD codes for the diagnosis of unruptured aneurysm (437.3) with procedural codes for clipping (39.51) or coiling (39.52, 39.79, or 39.72) of cerebral aneurysms and excluding all patients with a diagnosis of subarachnoid hemorrhage (430) and intracerebral hemorrhage (431). Mortality and discharge to a long-term facility were evaluated for both clipping and coiling patient populations. RESULTS: The fraction of unruptured aneurysms treated with coiling increased from 20% in 2001 to 63% in 2008. For surgical clipping, the percentage of patients discharged to long-term facilities was 14.0% (4184/29,918) compared with 4.9% (1655/34,125) of coiled patients (P < .0001). Clipped patients also had a higher mortality rate because 344 (1.2%) clipped patients died compared with 215 (0.6%) coiled patients (P < .0001). Between 2001 and 2008, the overall number of adverse outcomes from treatment had decreased from 14.8% to 7.6%. CONCLUSIONS: The use of endovascular coiling relative to surgical clipping of unruptured intracranial aneurysms is associated with decreasing periprocedural morbidity and mortality among patients treated in the United States from 2001 to 2008.

[Role of radiotherapy in heterotopic ossification]. / Rôle de la radiothérapie dans l'ossification hétérotopique.

PURPOSE: To evaluate the use of radiation therapy for the prevention of heterotopic ossification. PATIENTS AND METHODS: Twenty-two patients, 20 to 76 years old were irradiated for the prevention of heterotopic ossification. All patients received a postoperative irradiation consisting of 700 cGy delivered by 18 MV photons using a linear accelerator. The delay between surgery and irradiation was 24 hours for 20 patients, 48 hours for three patients, 72 hours for two patients and 96 hours for one patient. The follow-up of all patients was based on radiologic findings (Brooker score) as well as the clinical status of the articulation before and after surgery. Of the 14 cases for which follow-up data was available, seven received primary prophylaxis and seven received secondary prophylaxis. RESULTS: Heterotopic ossification prophylaxis using radiation therapy was radiologically successful in 71.5% of patients: 85.7% success for patients receiving primary prophylaxis and 57.1% success for patients receiving secondary prophylaxis. No functional failure was reported. No patient developed radiation related side effects. CONCLUSION: Radiation therapy is proven to be effective in preventing heterotopic ossification. A larger study group is needed in order to compare our results with those seen in the literature.

[Von Meyenburg disease found during laparoscopic surgery: report of two cases]. / Maladie des complexes de von Meyenburg (micro-hamartomes biliaires) découverte lors d'une chirurgie laparoscopique: à propos de deux observations.

The authors report two cases of von Meyenburg complexes disease found during laparoscopic surgical procedures. The first patient (41 years old) had multiple gallbladder stones with recurrent hepatic colics. The second patient (45 years old) had gastroesophageal reflux with recurrent peptic esophagitis. In both cases, multiple millimetric and superficial hepatic lesions were found during the exploration of the abdominal cavity. Then, an hepatic biopsy was done because the macroscopic aspect should suspect secondary metastatic lesions. Histological result made the diagnosis of von Meyenburg complexes disease (biliary microhamartomas). It seems to be important to know this anomaly of the ductal plate development and to do a liver biopsy during laparoscopy to affirm the diagnosis and cancel the diagnosis of multiple hepatic metastasis. In fact, this congenital pathology could be associated with increased risk of cholangiocarcinoma of the liver. The modality of radiological monitoring still remains to be defined.

[Acute toxicity in 50 patients with prostate cancer treated with conformal radiation therapy]. / Evaluation de latoxicité aiguë chez 50 patients atteints de cancer de la prostatetraités par radiothérapie conformationnelle.

PURPOSE: To report our experience with 3D conformal radiotherapy for prostate cancer. MATERIAL AND METHODS: We reviewed our first 50 patients diagnosed with prostate cancer. Median follow-up was 27 months (16-40 m). Median age 68 (52-74). T stage was: T1c = 12 ; T2a = 14; T2b = 10; T2c = 2; T3a = 10; T3b = 1 and T3c = 1. Gleason score (GS) 4-6 50% and GS 7-8 50%. Pretreatment PSA value of < 10 ng/ml 36%, 10-20 ng/ml 32% and > 20 ng/ml 32%. Forty patients received androgen ablation therapy 2 to 6 months before radiation. 3D conformal radiotherapy was used to allow a smaller amount of rectum and bladder to be in the high dose volume. An 18 Mv linear accelerator was used. The first 21 patients received 66 Gy, 28 patients received 70 Gy and one 74 Gy. RESULTS: The mean prostate volume was 45 cc for patients who received androgen ablation and 54 for the others (p = 0.02). The percentage of volume receiving more than 50 Gy (V50) was calculated for the rectum and bladder. The median V50 was 30% (10-55) for the rectum and 36% (5-70) for the bladder. Based on the RTOG grading (gr) for acute toxicity, there was no gr 3 gastrointestinal (GI) toxicity and only 1 gr 3 genitourinary (GU) toxicity. There were 9 gr 1 and 5 gr 2 GI toxicity, 10 gr 1 and 5 gr 2 GU toxicity. With our actual follow-up we have 2 late morbidities: gr 2 GU and one erectile failure. CONCLUSION: 3D conformal radiotherapy for prostate cancer has a good toxicity profile. Longer follow-up is needed to assess late toxicity and clinical outcome in this series.