Clinical value of amino acid imaging in paediatric brain tumours

Purpose: To evaluate single photon emission computed tomography (SPECT) using the amino acid l-3-[123I]-α-methyl tyrosine (IMT) and contrast enhanced magnetic resonance imaging (MRI) as diagnostic tools in primary paediatric brain tumours in respect of non-invasive tumour grading. Patients, materials, methods: 45 children with primary brain tumours were retrospectively evaluated. IMT uptake was quantified as tumour/nontumour- ratio, a 4-value-scale was used to measure gadolinium enhancement on contrast enhanced MRI. Statistical analyses were performed to evaluate IMT uptake and gadolinium enhancement in low (WHO I/II) and high (WHO III/ IV) grade tumours and to disclose a potential relationship of IMT uptake to disruption of blood brain barrier as measured in corresponding MRI scans. Results: IMT uptake above background level was observed in 35 of 45 patients. IMT uptake was slightly higher in high grade tumours but the difference failed to attain statistical significance. Grading of individual tumours was neither possible by IMT SPECT nor by gadolinium enhanced MRI. Conclusion: IMT is accumulated in most brain tumours in children. Tumour grading was not possible using IMT or contrast enhancement as determined by MRI. Neither morphological nor functional imaging can replace histology in paediatric brain tumours.

First description of a local Coprinopsis cinerea skin and soft tissue infection

Coprinopsis cinerea is an environmental fungus which can cause disseminated infections in immunocompromised patients, often leading to death. Here we report the case of a paediatric patient with an invasive wound infection due to C. cinerea, which was successfully treated with surgical debridement and oral posaconazole.

BRAF-KIAA1549 fusion transcripts are less frequent in pilocytic astrocytomas diagnosed in adults

AIM

Duplication of 7q34 resulting in generation of BRAF-KIAA1549 fusion transcripts is a characteristic event in pilocytic astrocytoma that may also aid distinction from diffuse astrocytic tumours. As data on BRAF-KIAA1549 fusion transcript status remain mainly limited to children, we aimed to examine the diagnostic value of BRAF-KIAA1549 fusion transcripts across all age groups.

METHODS

BRAF-KIAA1549 fusion transcript status was examined using reverse transcription polymerase chain reaction on formalin-fixed paraffin-embedded samples of 105 primary pilocytic astrocytomas [median patient age: 17 years (1-74 years)].

RESULTS

Informative results (distinct wildtype BRAF bands detectable) were obtained in 105/124 cases (85%). Fusion transcripts were detected in 53 of cases (51%). They were more often encountered in tumours of infratentorial location [42/67 (63%) vs. 11/38 (29%)] and comprised KIAA1549-Ex16_BRAF-Ex9 (32 cases), KIAA1549-Ex15_BRAF-Ex9 (14 cases) and KIAA1549-Ex16_BRAF-Ex11 (seven cases). Fusion transcripts were present in 79% of tumours diagnosed in the first decade of life, but only in 51% of patients aged 11-20 years, 42% of patients aged 21-30 years, 30% of patients aged 31-40 years and 7% of patients older than 40 years. On multivariate logistic regression analysis, the association of fusion transcript status and age was confirmed adjusting for tumour location (P = 0.006).

CONCLUSIONS

The frequency of BRAF-KIAA1549 fusion transcripts is significantly lower in adult patients with pilocytic astrocytoma, weakening the sensitivity of this specific diagnostic marker in that age group.

[Clinical value of amino acid imaging in paediatric brain tumours. Comparison with MRI]

PURPOSE

To evaluate single photon emission computed tomography (SPECT) using the amino acid l-3-[123I]-alpha-methyl tyrosine (IMT) and contrast enhanced magnetic resonance imaging (MRI) as diagnostic tools in primary paediatric brain tumours in respect of non-invasive tumour grading. Patients, materials, methods: 45 children with primary brain tumours were retrospectively evaluated. IMT uptake was quantified as tumour/nontumour-ratio, a 4-value-scale was used to measure gadolinium enhancement on contrast enhanced MRI. Statistical analyses were performed to evaluate IMT uptake and gadolinium enhancement in low (WHO I/II) and high (WHO III/IV) grade tumours and to disclose a potential relationship of IMT uptake to disruption of blood brain barrier as measured in corresponding MRI scans.

RESULTS

IMT uptake above background level was observed in 35 of 45 patients. IMT uptake was slightly higher in high grade tumours but the difference failed to attain statistical significance. Grading of individual tumours was neither possible by IMT SPECT nor by gadolinium enhanced MRI.

CONCLUSION

IMT is accumulated in most brain tumours in children. Tumour grading was not possible using IMT or contrast enhancement as determined by MRI. Neither morphological nor functional imaging can replace histology in paediatric brain tumours.

Percutaneous fetoscopic tracheal balloon occlusion in sheep

BACKGROUND

In order to minimize maternal trauma from current techniques for temporary fetoscopic tracheal occlusion, we tried to develop a percutaneous fetoscopic technique in sheep.

METHODS

In nine ewes between 77 and 128 days of gestation, the amniotic cavity was entered percutaneously. Each fetus was positioned and the feasibility of fetal laryngoscopy and percutaneous fetoscopic tracheal balloon occlusion was assessed.

RESULTS

Percutaneous intraamniotic access, fetal positioning, oropharyngeal sheath insertion, and fetoscopic laryngoscopy were achieved in all nine fetal sheep. Following some technical modifications to the working channel of the fetoscope, percutaneous fetoscopic tracheal balloon occlusion was successfully achieved in the last seven sheep.

CONCLUSION

Percutaneous fetoscopic balloon occlusion of the fetal trachea can effectively and safely be achieved in sheep. Because intraamniotic spatial relationships, fetal position, and umbilical cord length are technically less favorable in sheep, our operative techniques might be feasible in humans even if difficult intraamniotic conditions are encountered.

Percutaneous fetoscopic patch coverage of experimental lumbosacral full-thickness skin lesions in sheep

BACKGROUND

In order to minimize maternal trauma from open fetal surgery for prenatal coverage of fetal myelomeningoceles in humans, we assessed the feasibility of a percutaneous fetoscopic approach in sheep.

METHODS

In seven ewes between 90 and 100 days of gestation, the amniotic cavity was entered percutaneously. Each fetus was postured and a full-thickness skin lesion was created in the lumbosacral region. Then, the feasibility of covering this lesion with a patch and fetal skin by standard endoscopic suturing techniques (n = 3) or robot assistance (n = 4) was assessed.

RESULTS

Percutaneous fetoscopic patch and skin coverage of the full-thickness skin lesion was achieved in six of the seven fetal sheep. Five fetuses survived gestation and were delivered healthy.

CONCLUSIONS

Percutaneous fetoscopic posturing and patch coverage of lumbosacral full-thickness skin lesions can effectively and safely be achieved in sheep. This approach promises to provide a substantial reduction of maternal trauma from fetal surgery for myelomeningoceles.