Changes in functional MRI signals after 3D based radiotherapy of glioblastoma multiforme.

The purpose of our study was to examine the potential effects of conventional 3D based radiotherapy on functional MRI activation areas following the treatment of glioblastoma multiforme. Seventeen patients with a histologically proven glioblastoma multiforme were enrolled in this study. A functional MRI examination was performed alongside the planning CT and conventional MRI prior to the delivery of conventional 3D based radiotherapy. All patients received 3D based postoperative radiotherapy (up to 60 Gy) combined with temozolomide. Follow-up fMRI examinations were performed after completion of the treatment in the 6th week and in 3 months time. Changes of the task related activation areas were registered and analyzed. The difference in changes of high dose and low dose areas of the brain were also registered and analyzed. The comparison of the pretreatment and 6th week control fMRI activation areas revealed significant changes in motor activation and listening tasks in the case of brain areas which received a high dose (over 40 Gy). Based on the population level statistical parametric images (motor activation tasks) acquired at the 6th week control examination, a significant increase of signal was registered in the precuneus region and in the globus pallidus region. When comparing the 6th week and 3rd month activation signals, no significant changes were registered. Our results demonstrate the influence of radiotherapy on functional MRI signals within the human brain. Based on our findings, functional activation transfers from high dose areas to low dose areas. In case of the motor activation tasks, activations of the secondary motor area were observed following radiotherapy.

Skeletal metastatic carcinomas from the Roman period (1st to 5th Century AD) in Hungary.

OBJECTIVES: According to paleopathological records, tumors have a great antiquity. The prevalence of cancer in ancient populations might have differed from that in modern humans because of substantial differences in environmental factors, life expectancy and the availability of treatment. This study presents 3 cases of probable skeletal metastatic carcinoma from the Roman period (1st-5th century AD) in Hungary, showing the development of bone metastases of cancer without chemo- and radiotherapy. METHODS: All skeletons were subjected to a careful macroscopic investigation, which was extended by radiological, stereo- and scanning electron microscopic analyses. RESULTS: In 1 case, the mixed nature and localization of the lesions, as well as the sex and age of the individual, suggested breast cancer as the primary focus. In the other 2 cases, based on the mostly osteoblastic nature and the localization of the lesions as well as on the sex and age of the individuals, the most probable diagnostic option is prostate carcinoma with skeletal metastases. CONCLUSIONS: In view of the scarcity of cancer metastases that have been diagnosed in archeological specimens in general, identification of all examples of cancer in antiquity represents an important contribution both to paleopathology and to modern medicine.

Integrating functional MRI information into conventional 3D radiotherapy planning of CNS tumors. Is it worth it?

The purpose of our study was to examine the potential benefits of integrating functional MRI (fMRI) information into the 3D-based planning process for central nervous system (CNS) malignancies. Between 01.01.2008 and 01.12.2009, ten patients with astrocytoma (both low and high-grade histological type) were enrolled in this study. Before the planning process, conventional CT planning, postoperative MR, and individual functional MRI examinations were conducted. For the functional MRI examination four types of conventional stimuli were applied: acoustic, visual, somatosensory, and numeric. To examine the potential benefits of using fMRI-based information, three different types of theoretical planning were applied and compared: 3D conformal plan without fMRI information, 3D conformal plan with fMRI information, and IMRT plan with fMRI information. DVH analysis and the NTCP model were used for plan comparison. When comparing planning methods, distance-related subgroups were generated and studied. By using the additional fMRI information, a significantly higher sparing effect can be achieved on these ORs (both with conventional 3D-based planning and IMRT). In cases when the OR-PTV distance is less than 1 cm, IMRT seems to be a significantly better choice than conventional 3D-based techniques. IMRT also has an additional sparing effect on the optic tract and brainstem, especially for locations close to the midline. Our results demonstrated that using fMRI information in conventional 3D-based treatment planning has the potential benefit of significant dose reduction for the critical organs, with no compromise in PTV coverage even when using conventional 3D planning. fMRI can be widely used in low-grade cases (long life expectancy, lower acute and late toxicity) and also in cases with high-grade astrocytomas or distant metastases (higher dose to PTV with better sparing of risk organs). In cases when the OR-PTV distance is less than 1 cm, IMRT should be the choice of treatment for a higher sparing effect on functional active areas. Longer imaging and clinical follow up are needed to confirm the real sparing effect on these functional areas.

Open MR-guided high-dose-rate (HDR) prostate brachytherapy: feasibility and initial experiences open MR-guided high-dose-rate (HDR) prostate brachytherapy.

The aim of our pilot study was to demonstrate the feasibility and dosimetric quality of MR-guided HDR prostate brachytherapy in a low-field 0.35T open MRI scanner and to present our initial clinical experiences. 16 patients with intermediate- to high-risk localized prostate cancer were treated with 46-60 Gy of external beam radiotherapy preceded and/or followed by an 8 Gy MR-guided HDR boost. For interventions an MR compatible custom-made system, coaxial needles and plastic catheters were used. Template reconstruction, trajectory planning, image guidance, contouring and treatment planning were exclusively based on MR images. For treatment planning, dose-point- and anatomy-based inverse planning optimization was used. Image quality was found to be good to excellent in almost all cases. The mean catheter placement accuracy modeled by Rayleigh distribution was 2.9 mm with a sigma value of 2.3 mm. The mean and standard deviation (SD) of the dosimetric results for the target volume were the following: V100: 94.2 ± 4.3%, V150: 43.9 ± 6.8%, V200: 18.5 ± 5.9%. The mean D(0.1), D(1) and D1 values for the intraprostatic urethra were 117.6 ± 12.5%, 98.5 ± 19.9% and 122.3 ± 16.4%, respectively. Regarding the rectal wall the mean D(0.1), D(1) and D(2) values were 77.3 ± 7.2%, 64.8 ± 7.5%, and 53.2 ± 9.1%, respectively. The mean maximum dose for the inner rectal surface was 53.5 ± 9.2%. No RTOG Grade 3 or worse acute toxicities were observed. Our method seems to be a promising approach for performing feasible, accurate and high-quality MR-guided HDR prostate brachytherapy. To determine the long term side effects and outcome higher number of patients, additional follow-up is needed.

Integrating functional MRI information into radiotherapy planning of CNS tumors-early experiences.

The purpose of our study was to examine the integration of functional MRI (fMRI) information into 3D based planning process of the central nervous system (CNS) malignancies. Between 01.01.2008 and 01.12.2008 four patients with astrocytoma were enrolled to this study. Before the planning process conventional planning CT, postoperative MR and individual functional MRI examinations were delivered. For the functional MRI examination the following four types of stimulus were applied: acoustic, visual, somatosensory and numeral. Three different theoretical planning situations were applied and compared: 3D conformal plan without fMRI information, 3D conformal plan with fMRI information and IMRT plan with fMRI information. For plan comparison DVH analysis, and NTCP model were used. fMRI based OR definition resulted in 4 additional OR's in the contouring process. As these cases demonstrate, an average of 50% dose reduction was achieved in OR, OR2 and OR3 with IMRT and fMRI based 3D planning, especially in case of midline localization and big tumor extent. IMRT provides additional sparing effect in the optic tract and brainstem, especially for localizations close to the midline. Our results demonstrated that using fMRI information in conventional 3D based treatment planning potentially benefits significant dose reduction in critical organs, with no compromise in PTV coverage. fMRI can be widely used even in low grade cases (long life expectancies, lower acute and late toxicity in radiotherapy) and in cases with high grade astrocytomas or metastases (higher dose to PTV with better risk organ sparing in radiotherapy).

3-D conformal photon boost in the treatment of early stage breast cancer: four year follow up results.

In the treatment of early stage breast cancer, breast conserving surgery (BCS) followed by whole breast irradiation (WBI) is the standard treatment. The impact of the tumor bed boost following WBI is well-defined, but there are various delivery methods. In this study we demonstrate our 4 year experience with the 3-D conformal boost technique. Between January 2004 and June 2005, 77 early stage (Stage I-II) breast cancer patients were treated in our institute with whole breast irradiation (WBI, 50.4 Gy in 28 fractions) after breast conserving surgery. Following WBI, 3-D conformal photon boost was delivered (10-16 Gy in five to eight fractions) for all patients. The clinical outcome was retrospectively recorded in terms of survival and local control. The side effect profile (fibrosis, fat necrosis and cosmetic outcome) was also recorded and studied. In our patient group the mean follow up time was 46.8 months (median: 52, range: 17-71, SD: 14.4) The 4-year probability of local tumor control was 96% (crude rate: 74/77-96.1%), the 4-year probability of overall survival was 96% (crude rate: 74/77-96.1%) in this patient group. In case of the distant metastasis free survival the probability was 89, 5% (crude rate: 70/77-90, 1%). Probability of disease specific survival was 98% (crude rate: 76/77-98. 7%). Local relapse occurred in three cases (3.9%). In ten cases (12.9%) asymptomatic grade I-II breast fibrosis, in eight cases (10.4%) asymptomatic breast fat necrosis were registered. For 14 patients (18.2%) asymptomatic lung fibrosis was recorded on the control CT scans. In term of the relapse free survival, the close resection margin and the nodal positivity resulted in significant difference in favor of the clear resection margin group and the node negative group. In this study the 3-D conformal photon boost resulted in good local control and side effect profile. The presence of tumor bed clips resulted in significantly lower boost PTV volumes, but no correlation was found between the irradiated boost volume and the breast fibrosis. In the relapse free survival analysis, nodal negativity and clear margin status resulted in significantly better RFS.

Technical feasibility of transperineal MR-guided prostate interventions in a low-field open MRI unit: canine study.

Magnetic resonance imaging (MRI) provides superior visualization of the prostate, its substructure, surrounding tissues, and, most important, focal lesions or cancer. The purpose of our canine study was to demonstrate the feasibility of a low-field (0.35 T) transperineal system that enables precise MR image guidance of prostate interventions. The canines were placed in the right lateral decubitus position. Template reconstruction, trajectory planning, contouring were based on T2-weighted FSE images. For image guidance and target confirmation, fast gradient spoiled-echo (FSPGR) sequence was used. MR compatible coaxial needles were manually inserted through the perineum to the base of the prostate. After satisfactory position was confirmed, brachytherapy catheters were placed through the coaxial needles. The mean deviation of the needle displacements was 2.9 mm with a median value of 2.7 mm. 97% of the errors were less than 4.0 mm. The needle placement accuracy was modelled by the Rayleigh distribution with a sigma value of 2.3 mm. Visual confirmation of needle placements was demonstrated on pathology tissue slices. The time needed for each step was: anaesthesia - 15 min, setup and positioning - 15 min, initial imaging - 15 min, template registration, projection - 15 min, contouring, trajectory planning, insertion of 12 needles - 60 min Based on our canine experiences our method seems to be a promising approach for performing feasible, accurate, reliable and high-quality prostate MR guidance within a reasonable time span.