Hypofractionated irradiation for gliomas with 45.5Gy in 13 fractions: a retrospective study.

AIM: The aim of the present retrospective study was to evaluate the efficacy and toxicity of a hypofractionated radiotherapy (HFRT) schedule for grade IV glioblastoma multiforme (GBM). METHODS: Fourteen elderly patients with KPS less than 70, received 13 fractions of 350cGy with 3D-conformal technique (3DCRT) and non-coplanar fields. Acute and late skin and CNS toxicity was graded according to EORTC/RTOG criteria. RESULTS: The median follow-up was 9 months. All patients completed the irradiation without interruptions due to toxicity and received temozolomide (TMZ) after the completion of 3DCRT. The KPS during RT and at follow-up was not significantly changed (P=0.108). The median overall survival was 7 months. No severe skin acute or late toxicity was noted. In terms of CNS toxicity, only one patient presented grade III toxicity requiring hospitalization for two days. The irradiation schedule of 45.5Gy in 13 fractions seems effective and without moderate or severe toxicity. CONCLUSION: The suggested HFRT schedule might be an alternative one, for elderly patients with dismal prognosis, unfit for six weeks of daily irradiation. Prospective studies are needed for further validation of our results, especially with the use of TMZ.

Sucralfate gel as a radioprotector against radiation induced dermatitis in a hypo-fractionated schedule: a non-randomized study.

External beam radiotherapy with high doses provokes many acute skin reactions, such as erythema and moist desquamation. Many topical preparations are used in radiation oncology departments in the skin care. Sucralfate humid gel, a colloidal physical form of the anti-ulcer drug sucralfate, promotes epithelial regeneration and activates cell proliferation. Based on this knowledge, we performed a non-randomized clinical trial to evaluate the efficacy of topical sucralfate gel in 30 breast cancer patients receiving postoperative accelerated hypofractionated photon beam therapy. The comparison was performed with 30 patients as historical controls. The acute reaction of the skin was significantly lower in the group receiving the sucralfate gel (p<0.05, Mann Whitney test), while 90% of the patients had no evidence of radiation induced skin toxicity. There was no sucralfate gel related toxicity reported by any patient in this study. More patients in a randomized way are needed for more definite results.

Permanent implantation as brachytherapy technique for prostate carcinoma-review of clinical trials and guidelines.

Brachytherapy nowadays has become a widely accepted treatment modality in the management of localized prostate cancer. With recent improvements in ultra-sound technology, imaging, treatment planning and post-implant dosimetry, permanent implantation has become minimally invasive, well tolerated, and safe and most importantly has progressed to a treatment modality comparable to external beam radiation therapy (EBRT) and radical prostatectomy. Multiple studies have proven the efficacy of brachytherapy analyzing also its superiority in health related quality of life; especially in potency preservation after treatment.

Navigation through vector addition.

During short foraging excursions away from their home, central place foragers update their position relative to their point of departure by processing signals generated by locomotion. They therefore can home along a self-generated vector without using learned references. In rodents and other mammals, this path integration process (dead reckoning) can occur on the basis of purely internal signals, such as vestibular or proprioceptive (re)afferences. We report here that hamsters are also capable of proceeding to a previously learned feeding site through vector information from locomotion only. The subjects compute the direction and distance to the goal by subtracting their current-position vector from the stored nest-to-goal vector. This computation pertains to locations per se and therefore occurs in absolute space, independently of landmark objects. If available, prominent visual cues merely serve to confirm the path planned through the addition of self-generated vectors, whereas visual as well as nonvisual references confirm that the subject has arrived at the goal site.

Individual canine airways responsiveness to aerosol histamine and methacholine in vivo.

Inhalational challenges to histamine and methacholine (Mch) are commonly used to measure airway reactivity. In this study, we investigated the serial distribution of individual airway responsiveness in vivo following stimulation with histamine or methacholine by directly measuring airway area with high resolution computed tomography (HRCT). Anesthetized dogs were challenged on separate days to increasing aerosol concentrations of histamine or Mch. Airway areas of 13 or 14 individual airways in each dog ranging in size from 1.1 to 16.9 mm in diameter at baseline were measured. Dose response curves for each agonist showed a similar responsiveness to each agonist over all airway sizes measured. There was a slightly greater individual airway responsiveness to Mch throughout the airway tree, and this greater responsiveness was also present in those airways that are responsible for the decreased Cdyn observed with Mch challenge. We conclude that in vivo aerosol challenges with histamine or methacholine do not lead to preferential construction of large or small airways.

Further data on conflict behaviour in golden hamsters: shifting between alternative sets of directional information.

Golden hamsters were trained to collect food in two differently patterned test boxes, linked to each other and to the nest by a T-shaped tube. To choose the correct goal direction from each box entrance the subjects could use either locomotor or visual cues. In test trials the central arm of the T-tube and the nest were rotated by 180°, setting visual and locomotor information in conflict. For one group of subjects, only the boxes were illuminated, whereas for a second group a general visual background was added. Locomotor information prevailed over visual for the majority of group 1 subjects. The second group gave the same weight to locomotor and visual cues in choosing the initial direction, but again depended more on locomotor cues for their final orientation. In a complementary test using the group 1 subjects, the hamsters entered the test box directly (without passing through the T-tube) and were therefore deprived of learned locomotor cues. Most animals chose the visually correct goal, showing that they had also associated the food locations with the visual cues. The experimental set-up favoured conflict resolution by shifting between locomotor and visual cues rather than by choosing compromise directions. This suggests that both kinds of information were processed simultaneously but could be used successively throughout each hoarding excursion.

Identifying location by dead reckoning and external cues.

Golden hamsters can orient towards specific points in their environment using location- based visual cues and/or dead reckoning based on vestibular and proprioceptive signals. The relative weight of these different kinds of information was investigated in an apparatus consisting of three identical, square compartments joined by tunnels, with the subject's own nest box at one end. Each compartment contained a feeding site and a weak light spot, the relation between the feeding site and the light spot being different in the three compartments. The animals were trained to hoard food in succession from the three feeding locations, in darkness. During test trials, the light spots were either suppressed or moved to new locations, thus being set in conflict with other kinds of spatial information. In the majority of trials, the subjects proceeded fairly directly to the feeding places, independently of the presence and position of the light spots. This performance may be explained through rote motor learning, which may be initiated with respect to tactile cues previously associated to the goal. However, more flexible, indirect trajectories towards the goal suggest that the subjects kept track of their location within the test space and therefore depended simultaneously on dead reckoning and a map. A control experiment in which the goals were moved along with the visual cues excluded the use of olfactory cues from the food source and confirmed the role of dead reckoning.