No abstract

A fourteen years-old boy was treated post-operatively with proton therapy for a recurrent low-grade oligodendroglioma located in the tectal region. Six months after the end of irradiation (RT), a new enhancing lesion appeared within the radiation fields. To differentiate disease progression from radiation-induced changes, dynamic susceptibility contrast-enhanced (DSCE) MRI was used with a T2* sequence to study perfusion and permeability characteristics simultaneously. Typically, the lesion showed hypoperfusion and hyperpermeability compared to the controlateral normal brain. Without additional treatment but a short course of steroids, the image disappeared over a six months period allowing us to conclude for a pseudo-progression. The patient is alive in complete remission more than 2 years post-RT.

VDD and VDI were common in both HIV-infected and control groups, and serum 25(OH)D concentrations were significantly lower in controls than in HIV-infected children.

AIMSTo investigate D] population pharmacokinetics in children and adolescents, to establish factors that influence 25(OH)D pharmacokinetics and to assess different vitamin D3 dosing schemes to reach sufficient 25(OH)D concentrations (>30 ng ml −1 ). METHODSThis monocentric prospective study included 91 young HIV-infected patients aged 3 to 24 years. Patients received a 100 000 IU vitamin D3 supplementation. A total of 171 25(OH)D concentrations were used to perform a population pharmacokinetic analysis. RESULTSAt baseline 28% of patients had 25(OH)D concentrations below 10 ng ml −1 , 69% between 10 and 30 ng ml −1 and 3% above 30 ng ml −1 . 25(OH)D pharmacokinetics were best described by a one compartment model with an additional production parameter reflecting the input from diet and sun exposure. The effects of skin phototype and bodyweight were significant on 25(OH)D production before any supplementation. The basal level was 27% lower in non-white skin phototype patients and was slightly decreased with bodyweight. No significant differences in 25(OH)D concentrations were related to antiretroviral drugs. To obtain concentrations between 30 and 80 ng ml −1 , patients with baseline concentrations between 10 and 30 ng ml −1 should receive 100 000 IU per 3 months. However, vitamin D deficient patients (<10 ng ml −1 ) would need an intensive phase of 100 000 IU per 2 weeks (two times) followed 2 weeks later by a maintenance phase of 100 000 IU per 3 months. CONCLUSIONSSkin phototype and bodyweight had an influence on the basal production of 25(OH)D. According to 25(OH)D baseline concentrations, dosing schemes to reach sufficient concentrations are proposed.