Practising Mathematics Teacher Education: Expanding The Realm of Possibilities

It is often said that student teachers’ underlying beliefs of what mathematics consists of and how it should be taught are restricted in two ways. On the one hand, future elementary teachers in general use only weak mathematical conceptions, which often do not help them to realise their educational ambitions. On a general educational level, many of these students advocate discovery learning and collective problem solving, but when it comes down to the mathematical activities that have to be prepared, their experience of “traditional” school mathematics is of little help. On the other hand, future (higher) secondary teachers mostly are very well prepared with respect to formal academic mathematics when entering mathematics education programmes, either because they have already passed a mathematical formation at university or because their teacher education programmes emphasise the study of academic mathematics and not of educational or didactical modules

Variable nitrogen application based on crop sensing

Paper presented to the International Fertiliser Society at a conference held Cambridge (GB), 10 Dec 1998Available from British Library Document Supply Centre-DSC:6732.105(423) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

NIMG-79. EARLY TREATMENT RESPONSE ASSESSMENT USING O-(2-18F-FLUOROETHYL)-L-TYROSINE (FET) PET COMPARED TO MRI IN MALIGNANT GLIOMAS TREATED WITH ADJUVANT TEMOZOLOMIDE CHEMOTHERAPY

AbstractBACKGROUNDThe goal of this prospective study was to compare the value of conventional MRI and O-(2-18F-fluoroethyl)-L-tyrosine (FET) PET for response assessment in patients with malignant glioma treated with first-line adjuvant temozolomide chemotherapy (TMZ).METHODSAfter biopsy/resection and completion of radiotherapy with concomitant temozolomide, 34 malignant glioma patients (glioblastoma, n=31; IDH-wildtype anaplastic astrocytoma, n=2; H3K27-mutated midline glioma, n=1) (age range, 20–66 years) were subsequently treated with adjuvant TMZ (5/28). FET-PET scans were performed at baseline and after 10–12 weeks. The first follow-up MRI after radiotherapy (9 ± 3 weeks) was compared with the early postoperative MRI. We obtained FET metabolic tumor volumes (MTV) and tumor/brain ratios (TBR). Threshold values of FET-PET parameters for treatment response were established by ROC analyses using the progression-free survival (PFS) ≤/>9 months as reference. MRI response assessment was based on RANO criteria. The predictive ability of FET-PET thresholds and MRI changes on early response assessment was evaluated subsequently concerning PFS using univariate survival estimates.RESULTSRelative TBR changes were not predictive for a PFS>9 months (P>0.05), whereas the absolute MTV at follow-up significantly predicted a PFS>9 months (P=0.016; threshold, 14.5 ml). The relative MTV change enabled the most significant PFS prediction. Responders defined by relative MTV changes (threshold, ≤0%) had a significantly 2-fold longer PFS than non-responders (16 vs. 8 months, P=0.003). RANO criteria at the first follow-up MRI after radiotherapy were not predictive for a PFS>9 months (P=0.260). CONCLUSIONS: FET-PET appears to be useful for identifying responders to adjuvant TMZ early after treatment initiation

EARLY TREATMENT RESPONSE ASSESSMENT USING O-(2-F-18-FLUOROETHYL)-L-TYROSINE (FET) PET COMPARED TO MRI IN MALIGNANT GLIOMAS TREATED WITH ADJUVANT TEMOZOLOMIDE CHEMOTHERAPY

AbstractBACKGROUNDThe goal of this prospective study was to compare the value of conventional MRI and O-(2-18F-fluoroethyl)-L-tyrosine (FET) PET for response assessment in patients with malignant glioma treated with first-line adjuvant temozolomide chemotherapy (TMZ).METHODSAfter biopsy/resection and completion of radiotherapy with concomitant temozolomide, 34 malignant glioma patients (glioblastoma, n=31; IDH-wildtype anaplastic astrocytoma, n=2; H3K27-mutated midline glioma, n=1) (age range, 20–66 years) were subsequently treated with adjuvant TMZ (5/28). FET-PET scans were performed at baseline and after 10–12 weeks. The first follow-up MRI after radiotherapy (9 ± 3 weeks) was compared with the early postoperative MRI. We obtained FET metabolic tumor volumes (MTV) and tumor/brain ratios (TBR). Threshold values of FET-PET parameters for treatment response were established by ROC analyses using the progression-free survival (PFS) ≤/>9 months as reference. MRI response assessment was based on RANO criteria. The predictive ability of FET-PET thresholds and MRI changes on early response assessment was evaluated subsequently concerning PFS using univariate survival estimates.RESULTSRelative TBR changes were not predictive for a PFS>9 months (P>0.05), whereas the absolute MTV at follow-up significantly predicted a PFS>9 months (P=0.016; threshold, 14.5 ml). The relative MTV change enabled the most significant PFS prediction. Responders defined by relative MTV changes (threshold, ≤0%) had a significantly 2-fold longer PFS than non-responders (16 vs. 8 months, P=0.003). RANO criteria at the first follow-up MRI after radiotherapy were not predictive for a PFS>9 months (P=0.260). CONCLUSIONS: FET-PET appears to be useful for identifying responders to adjuvant TMZ early after treatment initiation