Robert Chrzan

Results of a phase II open-label, non-randomized trial of cisplatin chemotherapy in patients with BRCA1-positive metastatic breast cancer

IntroductionThe purpose of this investigation was to evaluate the efficacy of cisplatin chemotherapy in BRCA1 mutation carriers with metastatic breast cancer.MethodsIn a phase II, open-label study, 20 patients with metastatic breast cancer who carried a mutation in BRCA1 were treated with cisplatin 75 mg/m2 intravenously every 3 weeks as part of a 21-day cycle for 6 cycles. Restaging studies to assess response were performed after cycles 2 and 6, and every three months thereafter.ResultsBetween July 2007 and January 2009, 20 patients were enrolled. Baseline characteristics were as follows: 65% had prior adjuvant chemotherapy, 55% had prior chemotherapy for metastatic breast cancer; mean age was 48 years (ranges 32 to 70); 30% estrogen receptor (ER) or progesterone receptor (PR)+, 70% ER/PR/Human Epidermal Growth Factor Receptor 2 (HER2)- and 0% HER2+. Overall response rate was 80%; nine patients experienced a complete clinical response (45%) and seven experienced a partial response (35%). Overall survival was 80% at one year, 60% at two years and 25% at three years. Four of the 20 patients are alive four years after initiating treatment. The median time to progression was 12 months. The median survival from the start of cisplatinum treatment was 30 months. Cisplatin-related adverse events, including nausea (50%), anemia (5%) and neutropenia (35%) were mostly mild to moderate in severity.ConclusionsThis phase II study demonstrates that cisplatin chemotherapy has high activity in women with a BRCA1 mutation and metastatic breast cancer and is generally well tolerated.Trial registrationThis trial is registered retrospectively on the clinical trials website ClinicalTrials.gov. The identifier is NCT01611727.

Cranioplasty prosthesis manufacturing based on reverse engineering technology

Summary Background Most patients with large focal skull bone loss after craniectomy are referred for cranioplasty. Reverse engineering is a technology which creates a computer-aided design (CAD) model of a real structure. Rapid prototyping is a technology which produces physical objects from virtual CAD models. The aim of this study was to assess the clinical usefulness of these technologies in cranioplasty prosthesis manufacturing. Material/Methods CT was performed on 19 patients with focal skull bone loss after craniectomy, using a dedicated protocol. A material model of skull deficit was produced using computer numerical control (CNC) milling, and individually pre-operatively adjusted polypropylene-polyester prosthesis was prepared. In a control group of 20 patients a prosthesis was manually adjusted to each patient by a neurosurgeon during surgery, without using CT-based reverse engineering/rapid prototyping. In each case, the prosthesis was implanted into the patient. The mean operating times in both groups were compared. Results In the group of patients with reverse engineering/rapid prototyping-based cranioplasty, the mean operating time was shorter (120.3 min) compared to that in the control group (136.5 min). The neurosurgeons found the new technology particularly useful in more complicated bone deficits with different curvatures in various planes. Conclusions Reverse engineering and rapid prototyping may reduce the time needed for cranioplasty neurosurgery and improve the prosthesis fitting. Such technologies may utilize data obtained by commonly used spiral CT scanners. The manufacturing of individually adjusted prostheses should be commonly used in patients planned for cranioplasty with synthetic material.

Three-dimensional stereotactic atlas of the adult human skull correlated with the brain, cranial nerves, and intracranial vasculature.

BACKGROUND Although the adult human skull is a complex and multifunctional structure, its 3D, complete, realistic, and stereotactic atlas has not yet been created. This work addresses the construction of a 3D interactive atlas of the adult human skull spatially correlated with the brain, cranial nerves, and intracranial vasculature. NEW METHOD The process of atlas construction included computed tomography (CT) high-resolution scan acquisition, skull extraction, skull parcellation, 3D disarticulated bone surface modeling, 3D model simplification, brain-skull registration, 3D surface editing, 3D surface naming and color-coding, integration of the CT-derived 3D bony models with the existing brain atlas, and validation. RESULTS The virtual skull model created is complete with all 29 bones, including the auditory ossicles (being among the smallest bones). It contains all typical bony features and landmarks. COMPARISON WITH EXISTING METHOD(S) The created skull model is superior to the existing skull models in terms of completeness, realism, and integration with the brain along with blood vessels and cranial nerves. CONCLUSIONS This skull atlas is valuable for medical students and residents to easily get familiarized with the skull and surrounding anatomy with a few clicks. The atlas is also useful for educators to prepare teaching materials. It may potentially serve as a reference aid in the reading and operating rooms.

Can treatment using radiolabelled somatostatin analogue increase the survival rate in patients with non-functioning neuroendocrine pancreatic tumours?

BACKGROUND The aim of the study was to assess the effectiveness of peptide receptor radionuclide therapy (PRRT) in patients with non-functioning neuroendocrine pancreatic tumours (NFPNTs) and to compare survival rates in patients with NFPNTs and in patients with other neuroendocrine tumours (NETs) treated using radiolabelled somatostatin analogue in our Department. We would like to analyze factors potentially determining the effectiveness of the therapy and also to assess the myelo- and nephrotoxicity. MATERIAL AND METHODS Fourteen patients with disseminated disease and/or inoperable NFPNT were qualified to PRRT based on positive SRS (somatostatin receptor scintigraphy). There were 5 men and 9 women, with Karnofskys index>70%. RESULTS In the whole group of patients, partial response was observed in 21.4%, stabilization of the disease in 42.9%, and progression of the disease in 35.7% of patients. Mean observation time was 19±13 months, mean time to progression was 12±9 months, and mean time to death was 16±9 months. Six patients died--four of them due to progression of the disease, two due to myocardial infarction. After PRRT we did not observe clinically significant haemotoxicity and/or nephrotoxicity. CONCLUSIONS 1. Peptide receptor radionuclide therapy may be a safe and effective treatment option in patients with NFPNTs, leading to stabilization or regression of the disease in the majority of patients. 2. There is no statistically significant difference in survival rate between patients with NFPNTs and NETs of other localization treated with PRRT.

Hyperdense middle cerebral artery sign as the only radiological manifestation of hyperacute ischemic stroke in computed tomography

OBJECTIVES The main aim of the study was to find the effect of hyperdense middle cerebral artery sign (HMCAS), as the only admission computed tomography (CT) manifestation of ischemic stroke involving middle cerebral artery (MCA) region, on the extent of stroke measured by Alberta Stroke Program Early CT score (ASPECTS) in the follow-up CT. The secondary aim was to determine the correlation between length of hyperdense MCA segment on admission CT and ASPECTS in follow-up CT. METHODS The group analyzed consisted of 118 patients with ischemic MCA region stroke, with no early signs of brain tissue ischemia on admission CT, but infarcts confirmed in follow-up CT, with extent evaluated using ASPECTS. For the subgroups: 66 patients with HMCAS present and 52 with HMCAS absent, median ASPECTS values were compared. In the subgroup with HMCAS present, length of hyperdense segment was measured and correlation with ASPECTS was determined. RESULTS The median ASPECTS 6 (min. 0, max. 9) in the subgroup with HMCAS present was significantly lower, compared to the score 8.5 (min. 0, max. 9) in the subgroup with HMCAS absent. Moderate correlation between the length of hyperdense segment and ASPECTS was found (R=-0.45). CONCLUSION In patients with ischemic stroke involving MCA region and no early signs of brain tissue ischemia on the admission CT, HMCAS is associated with significantly lower ASPECTS in the follow-up CT. There is moderate correlation between the length of hyperdense MCA segment and ASPECTS.

A Quantitative Method Using Head Noncontrast CT Scans to Detect Hyperacute Nonvisible Ischemic Changes in Patients With Stroke.

Because clinical evaluation of noncontrast computed tomography (CT) has a poor sensitivity in the evaluation of acute ischemic stroke, computer‐aided diagnosis may be able to facilitate the performance. Recently, we introduced a computational method for the detection and localization of visible infarcts. Herein, we aimed to evaluate and extend a previous method, the Stroke Imaging Marker (SIM), to localize nonvisible hyperacute ischemia.

Individually Fitted Hearing Aid Device Manufactured Using Rapid Prototyping Based on Ear CT. A Case Report.

Rapid prototyping is the technology of automatic freeform fabrication of physical objects from virtual CAD (computer aided design) models. For medical objects the models may be created using data from CT, MR or rotational angiography. We descriobe the case of a 83-year-old woman with essential bilateral hearing impairment as the effect of chronic otitis media. An individually fitted hearing aid was produced for the patient using stereolithography technology and vacuum casting based on data obtained during ear CT. Rapid prototyping may help in manufacturing individually adjusted biomedical prostheses, reducing the time of device production and improving its fitting.

The assessment of diagnostic medical images using 10-bit grayscale – fact or myth?

Purpose The aim of the study was to find tests for verification of 10-bit grayscale support for radiological workstation hardware/operating system and for DICOM viewer. Also, we wanted to perform the tests on available workstations. Material and methods The following tests were selected to verify 10-bit grayscale support: workstation hardware and operating system tests using DirectX SDK 10BitScanout10.exe and NEC 10bitdemo.exe programs, DICOM viewer tests using TG18-MP and TG18-QC patterns. The tests were performed on 14 radiological workstations in a local department of radiology and on 4 radiological workstations during the technical exhibition at the ECR (European Congress of Radiology) in 2017. Results Only 3 out of 14 local workstations passed the hardware and operating system 10-bit grayscale support test. Only one workstation passed the DICOM viewer 10-bit grayscale support test. Conclusions Hardware/operating system and DICOM viewer 10-bit grayscale support should be tested on every radiological workstation even if compatibility is stated by the manufacturer. Existing medical diagnostic display quality requirements should be adjusted so that 10-bit support for DICOM viewers is only a desirable option.

Quantification of image contrast of infarcts on computed tomography scans

Introduction Accurate identification of infarcts in non-contrast computed tomography (NC-CT) scans of the brain is fundamental in the diagnosis and management of patients with stroke. Quantification of image contrast properties at the boundaries of ischemic infarct regions in NC-CT can contribute to a more precise manual or automatic delineation of these regions. Here we explore these properties quantitatively. Methods We retrospectively investigated 519 NC-CT studies of 425 patients with clinically confirmed ischemic strokes. The average and standard deviation (SD) of patients’ age was 67.5 ± 12.4 years and the average(median)±SD time from symptoms onset to NC-CT examination was 27.4(12)±35.7 h. For every scan with an ischemic lesion identified by experts, the image contrast of the lesion vs. normal surrounding parenchyma was calculated as a difference of mean Hounsfield Unit (HU) of 1–5 consecutive voxels (the contrast window width) belonging to the lesion and to the parenchyma. This contrast was calculated at each single voxel of ischemic lesion boundaries (previously delineated by the experts) in horizontal and vertical directions in each image. The distributions of obtained horizontal, vertical and both contrasts combined were calculated among all 519 NC-CTs. Results The highest applicative contrast window width was identified as 5 voxels. The ischemic infarcts were found to be characterized by 6.60 HU, 8.28 HU and 7.55 HU mean values for distributions of horizontal, vertical and combined contrasts. Approximately 40–50% of the infarct boundary voxels were found to refer to the image contrast below 5 HU. Conclusion Low image contrast of ischemic lesions prevents accurate delineation of the infarcts in NC-CT.

MRI Disturbances Caused by Dental Materials

Dental materials are common sources of artifacts during brain MRI studies. The aim of the present study was to estimate the degree of image disturbance caused by dental materials during an MRI examination, and the risk of ferromagnetic materials being dislocated in the magnetic field. MR sequences where dental materials containing metals produced the smallest artifacts was also calculated. Thirty-five dental material samples containing metals were examined using the 1.5 T MR system. They consisted of the most commonly used dental restorations and root-canal instruments left in the oral cavity for iatrogenic reasons. Additionally, cubes (10×5×5 mm) and balls (10 mm diameter) were cast from commonly used dental alloys. No dislocation of the examined samples in the gelatin medium was observed. All the materials were found to produce artifacts characterised by similar images. The study showed that the presence of distant artifacts, besides those located in the area immediately surrounding the object, depends on the shape of the given material. The size of artifacts generated by the most commonly used fixed restorations was graded. The sequences in which artifacts were least pronounced were selected. No dislocation of samples in the 1.5 T field was observed during the examination. However they produced artifacts; the typical image of an artifact — a signal void zone surrounded by a hyperintensive rim. Alloys consisting of Ag-Pd, dental gold and amalgam distorted the MR image to the least degree. In the case of a routine spin echo (SE) sequence examination the smallest artifacts were generated in the FSE T2 and PD sequences.