Intra-tumoural PpIX concentrations exhibited pronounced inter- and intra-tumoural variations in glioblastoma, which are directly linked to variable degrees of fluorescence intensity. High intra-tumoural PpIX concentrations with strong fluorescence intensity and complete photobleaching after iPDT seem to be associated with favourable outcome. Real-time monitoring of PpIX fluorescence intensity and photobleaching turned out to be feasible and safe and might be employed for early treatment prognosis of iPDT.

Protoporphyrin IX (PpIX) produced from exogenous, orally administered 5-aminolevulinic acid (ALA) displays high tumor-selective uptake and is being successfully employed for fluorescence-guided resection (FGR) of human malignant gliomas. Furthermore, the phototoxicity of PpIX can be utilized for photodynamic therapy (PDT) of brain tumors, which has been shown previously. Here, the absolute PpIX concentration in human brain tissue was investigated following oral ALA administration (20 mg kg(-1) b.w.). An extraction procedure was used to quantify PpIX in macroscopic tissue samples, weighing 0.013-0.214 g, obtained during FGR. The PpIX concentration was significantly higher in vital grade IV tumors (5.8 ± 4.8 μm, mean ± SD, range 0-28.2 μm, n = 8) as compared with grade III tumors (0.2 ± 0.4 μm, mean ± SD, range 0-0.9 μm, n = 4). There was also a large heterogeneity within grade IV tumors with PpIX displaying significantly lower levels in infiltration zones and necrotic regions as compared with vital tumor parts. The average PpIX concentration in vital grade IV tumor parts was in the range previously shown sufficient for PDT-induced tissue damage following irradiation. However, the feasibility of PDT for grade III brain tumors and for grade IV brain tumors displaying mainly necrotic tissue areas without solid tumor parts needs to be further investigated.

The aim was to describe the development of a theoretical model for leader evaluation and development, an instrument based on this model, and a strategy for large scale implementation in the Swedish armed forces. The model rests on an interactional person by situation paradigm. It emphasises “developmental leadership”, which is inspired by transformational and functionalistic leadership approaches. The developmental leadership questionnaire (DLQ) was operationalised from the model and refined through structural equation modelling. The model and the DLQ will be used for three purposes: yearly evaluation of all personnel in the Swedish armed forces; yearly planning dialogues between each employee and his or her nearest supervisor; and a tool for leadership training. The implementation strategy includes an initial course in developmental leadership for all colonels. This is followed by the selection and training of local trainers, who, in turn, initiate the comprehensive programme locally. The system should be fully implemented by 2005.

Photodynamic therapy (PDT) for the treatment of prostate cancer has been demonstrated to be a safe treatment option capable of inducing tissue destruction and decreasing prostate specific antigen (PSA) levels. However, prostate-PDT results in large intra- and interpatient variations in treatment response, possibly due to biological variations in tissue composition and short-term response to the therapeutic irradiation. Within our group, an instrument for interstitial PDT on prostate tissue has been developed that combines therapeutic light delivery and monitoring of light transmission via numerous bare-ended optical fibers. Here, we present algorithms that utilize data on the light distribution within the target tissue to provide realtime treatment feedback based on a light dose threshold model for PDT. This realtime dosimetry module is implemented to individualize the light dose and compensate for any treatment-induced variations in light attenuation. More specifically, based on the light transmission signals between treatment fibers, spatially resolved spectroscopy is utilized to assess the effective attenuation coefficient of the tissue. These data constitute input to a block-Cimmino optimization algorithm, employed to calculate individual fiber irradiation times provided the requirement to deliver a predetermined light dose to the target tissue while sparing surrounding sensitive organs. By repeatedly monitoring the light transmission signals during the entire treatment session, optical properties and individual fiber irradiation times are updated in realtime. The functionality of the algorithms is tested on diffuse light distribution data simulated by means of the finite element method (FEM). The feasibility of utilizing spatially resolved spectroscopy within heterogeneous media such as the prostate gland is discussed. Furthermore, we demonstrate the ability of the block-Cimmino algorithm to discriminate between target tissue and organs at risk (OAR). Finally, the realtime dosimetry module is evaluated for treatment scenarios displaying spatially and temporally varying light attenuation levels within the target tissue. We conclude that the realtime dosimetry module makes it possible to deliver a certain light dose to the target tissue despite spatial and temporal variations of the target tissue optical properties at the therapeutic wavelength.

Participating in meaningful, challenging activities in different environments stimulates the occupational adaptation process; this is something occupational therapists could use to empower older persons to find their optimal occupational lives.