OS2.2 Chemotherapy for spinal gliomas in adults

BACKGROUND

Chemotherapy is a treatment option in patients diagnosed with anaplastic gliomas or glioblastomas of the spinal cord, or with recurrent lower graded WHO spinal gliomas that are no longer amenable to local treatment. The low incidence of spinal cord gliomas, particularly in adults, limits the ability to perform clinical trials. The role of chemotherapy in these tumors has remained unclear.

MATERIAL AND METHODS

We performed a retrospective study of 22 patients diagnosed with spinal gliomas who were treated with chemotherapy at any time during the disease course. Benefit from chemotherapy was estimated by applying Response assessment in neuro-oncology criteria. Data on radiotherapy, as well as the number of neurosurgical interventions were taken into consideration.

RESULTS

Most patients were diagnosed with astrocytoma WHO grade I-IV (N=14), the remaining patients were diagnosed with ependymoma (N=8). Median follow-up from start of chemotherapy was 92 months (95% CI, 72.6–111.4). The O6-methylguanyl-DNA-methyltransferase(MGMT)promoter methylation status was available in tumors of 12 patients: 9 tumors (75%) had an unmethylated MGMTpromoter. More than 50% of the patients had more than one neurosurgical intervention. After prior surgery 10 patients in the first-line setting had chemotherapy combined with radiotherapy, while 3 patients received chemotherapy only. The remaining 9 patients had initially received radiation therapy and chemotherapy was given at time of recurrence. In patients diagnosed with astrocytoma mainly temozolomide (TMZ) was applied (N=10), while one patient received CCNU and three patients had combination chemotherapy. Patients diagnosed with ependymoma had hydroxyurea (N=1), CCNU (N=1), TMZ (N=3) or combination chemotherapy (N=3). In the group of patients who had chemotherapy combined with radiation, response rates were as follows: anaplastic astrocytoma 3 stable diseases (SD), glioblastoma 1 complete response (CR) and 1 SD, and anaplastic ependymoma 1 SD. After chemotherapy in the group of patients previously irradiated, the following response rates were observed: 1 SD in pilocytic astrocytoma, 1 SD in diffuse astrocytoma, 3 SD in myxopapillary ependymoma, and 2 SD and 1 partial response (PR) in anaplastic ependymoma. All other patients experienced progressive disease. There was no indication for a favorable prognostic role ofMGMTpromoter methylation.

CONCLUSION

Spinal cord gliomas represent a heterogeneous group of tumors. Survival outcomes in response to chemotherapy in adult spinal glioma patients vary substantially, but individual patients appear to derive benefit from chemotherapy.

The influence of mode of anaesthesia for caesarean delivery on neonatal Apgar scores in the Czech Republic and Slovakia: secondary analysis of the results of an international survey in 2015

AIMS

The purpose of this international survey was to describe the impact of current practices and techniques of caesarean section on the neonatal Apgar score in the Czech Republic (CZE) and Slovakia (SVK).

METHODS

All Czech and Slovak departments that provide obstetric anaesthesia were invited to participate in a one-month (November 2015) prospective study that monitored in details all peripartum anaesthetic practices, delivered by anaesthesiologists. Participating centers recorded all data on-line in the CLADE-IS database (Masaryk University, CZE).

RESULTS AND DISCUSSIONS

We collected data of 10119 women who delivered 10226 newborns. A caesarean section was recorded in 25.1% of deliveries (CZE 23.2%; SVK 30%). General anaesthesia was used for caesarean section in 37.5% of the cases (CZE 40%, SVK 33%). There was no statistically significant difference in the Apgar score lower than 7 in the 1, 5 or 10 min in groups of general and regional anaesthesia for caesarean section, when only elective sections of in-term babies with birth weight over 2500 g were analyzed. We found no statistically significant differences in the Apgar score in newborns of women intubated for caesarean section in rocuronium (n=21; 2.2%) and suxamethonium (n=889; 93%).

CONCLUSION

We found no difference in neonatal outcomes in groups of general and regional anaesthesia for caesarean section when only out-of-risk newborns were analyzed. The risk factors were identified as follows: an acute caesarean section, preterm babies, birth weight less than 2 500 g, born in perinatological center and multiple pregnancy - second baby.

TRIAL REGISTRATION

ClinicalTrials.gov (ID: NCT02380586) https://clinicaltrials.gov/ct2/show/NCT02380586.

Zusammenhänge zwischen Eigenschaften von 131I-Therapiekapseln und der Radioiodkinetik

Ziel: Es sollte das Auftreten nichtreproduzierbarer Meßwerte bei Radioiodtest und Radioiodkinetik unter 131l-Therapie geklärt werden. Methoden: Der lodgehalt der Kapseln wurde kolonmetrisch und mit der Aktivierungsanalyse bestimmt. Die Messung der radiochemischen Reinheit erfolgte mittels HPLC und Elektrophorese. Das Löseverhalten der Kapseln wurde unter unterschiedlichen Bedingungen überprüft. Ergebnisse: Der lodgehalt der Kapseln schwankte zwischen 0,8 und ca. 100 μg/Kapsel. Die radiochemische Reinheit der Kapseln differierte ebenfalls (75%-99,5%). Hauptverunreinigung war lodat. Das Löseverhalten war ebenfalls unterschiedlich. Schlußfolgerung: Zusätzliches nichtradioaktives lod in den Therapiekapseln könnte eine Ursache verminderter Radioiodaufnahme unter Therapie sein.

Factors affecting the specific activity of [18F]fluoride from a [18O]water target

Aim: Characterisation of the influence of different polymeric tube materials of a water target system, used for the production of 18F activity, on the specific activity of radiotracers. Material, methods: Target water samples taken from different locations of the 18F water target system of a Cyclone® 18/9 cyclotron, equipped with Teflon® (PTFE) or polypropylene (PP) tubes, were analyzed for non-radioactive [19F]fluoride content. [19F]Fluoride content was measured by ion chromatography (IC20, Dinoex) with suppressed conductivity detection. Both the ion chromatographic results and the amount of 18F activity produced were used for the calculation of the specific activity (SA) of [18F]fluoride at the start of the labelling synthesis. To check these results, the SA of the labelled receptor ligand [18F]ZK811460 was also determined by using the different tubing materials. Results: Dose-exposed PTFE tubes of the target dispensing (loading) system were identified to be a major source of [19F]fluoride contamination. Conclusion: By replacing PTFE tubes of the target dispensing system with PP tubes, the content of 19F was reduced considerably resulting in an increase of SA of the radiotracer [18F]ZK811460 by factor of two.

Very stable 188Re-S4 chelates for labelling biomolecules

Aim: The preparation and stability of a new 188Re-S4-complex [S4 = (1-aza-18-crown-6)(O)C-C(SH)-C(SH)- C(O)NH-(CH2)3-NH-(CH2)3-NHC(O)-C(SH)-C(SH)- C(O)(1-aza-18-crown-6] was studied at therapeutic relevant radioactive concentrations. The results were compared with 188Re-MAG3 (MAG3: mercaptoacetyltriglycine) and 188Re-DMSA preparations (DMSA: dimercaptosuccinic acid) performed with the same highly concentrated [188Re]perrhenate solution (12-15 GBq/ml). Methods: The 188Re complexes were prepared by direct reduction of perrhenate (188Re-S4-complex) as well as via the 188Re- EDTA precursor complex (188Re-MAG3, 188Re-DMSA). The preparations were stabilised with 15 mg of ascorbic acid and analysed after 1, 2, and 24 hours by TLC and HPLC. Additionally, in vitro and in vivo stability studies were performed with the purified complexes. Results: After stabilisation with 15 mg of ascorbic acid, all of the complexes were nearly stable under nitrogen for hours, and only 2–8 % of perrhenate was observed after 24 h. In contrast, only the 188Re-S4 complex was completely stable in vitro and in all investigated in vivo samples after separation of ligand excess and reducing agent by HPLC. Conclusion: The bridging amine group or free carboxylic groups of the S4-ligand framework make available reactive positions for coupling biomolecules to the chelate. Thus it appears that the new 188Re-S4 complexes offer the possibility of stable and high specific activity labelling of biomolecules for therapeutic application.

[Direct Drive Simulation - Sound-Simulation of the Vibrant Soundbridge®]

BACKGROUND

The Direct-Drive-Simulation (DDS) tends to simulate the sound quality of hearing with the active middle ear implant Vibrant Soundbridge(®) (VSB). Up to now a scientific evaluation of the validity is missing. Furthermore, the test procedure has not been described yet. Aim of this study was to evaluate the test validity and to describe the test realization in detail.

MATERIAL AND METHODS

10 patients evaluated their sound impression on scales from 1 to 10 concerning sound quality during DDS, postoperative free field testing at least 3 month after the first fitting of the VSB and in the everyday life situation. 3 patients were implanted bilaterally. Together, 36 data sets could be analyzed.

RESULTS

Coupling of the Floating Mass Transducer (FMT), which was placed inside of a silicone probe during DDS was successful in all cases. In 11 out of 13 cases the coupling quality was judged as "good" an only in 2 cases as "medium". None of the patients needed local anesthesia. Comparing the evaluation of the sound impression during DDS preoperatively, and with the implanted VSB in free field testing and in everyday life no significant differences were found.

CONCLUSION

The DDS offers the possibility of a realistic preoperative sound simulation of the "VSB-hearing" in case of sensorineural hearing loss. Thus, the test is supposed to facilitate the patient's decision towards possible treatment options. The specialist gets additional information regarding the indication especially when audiologic indication criteria are critical. The DDS should be a basic part of the preoperative diagnostic prior to VSB-implantation.

An automatic method for accurate volume delineation of heterogeneous tumors in PET

PURPOSE

Accurate volumetric tumor delineation is of increasing importance in radiation treatment planning. Many tumors exhibit only moderate tracer uptake heterogeneity and delineation methods using an adaptive threshold lead to robust results. These methods use a tumor reference value R (e.g., ROI maximum) and the tumor background Bg to compute the volume reproducing threshold. This threshold corresponds to an isocontour which defines the tumor boundary. However, the boundaries of strongly heterogeneous tumors can not be described by an isocontour anymore and therefore conventional threshold methods are not suitable for accurate delineation. The aim of this work is the development and validation of a delineation method for heterogeneous tumors.

METHODS

The new method (voxel-specific threshold method, VTM) can be considered as an extension of an adaptive threshold method (lesion-specific threshold method, LTM), where instead of a lesion-specific threshold for the whole ROI, a voxel-specific threshold is computed by determining for each voxel Bg and R in the close vicinity of the voxel. The absolute threshold for the considered voxel is then given by Tabs=T×(R-Bg)+Bg, where T=0.39 was determined with phantom measurements.

VALIDATION

30 clinical datasets from patients with non-small-cell lung cancer were used to generate 30 realistic anthropomorphic software phantoms of tumors with different heterogeneities and well-known volumes and boundaries. Volume delineation was performed with VTM and LTM and compared with the known lesion volumes and boundaries.

RESULTS

In contrast to LTM, VTM was able to reproduce the true tumor boundaries accurately, independent of the heterogeneity. The deviation of the determined volume from the true volume was (0.8±4.2)% for VTM and (11.0±16.4)% for LTM.

CONCLUSIONS

In anthropomorphic software phantoms, the new method leads to promising results and to a clear improvement of volume delineation in comparison to conventional background-corrected thresholding. In the next step, the suitability for clinical routine will be further investigated.

Evaluation of PET quantification accuracy in vivo. Comparison of measured FDG concentration in the bladder with urine samples

Quantitative positron emission tomography (PET) requires accurate scanner calibration, which is commonly performed using phantoms. It is not clear to what extent this procedure ensures quantitatively correct results in vivo, since certain conditions differ between phantom and patient scans.

AIM

We, therefore, have evaluated the actual quantification accuracy in vivo of PET under clinical routine conditions.

PATIENTS, METHODS

We determined the activity concentration in the bladder in patients undergoing routine [18F]FDG whole body investigations with three different PET scanners (Siemens ECAT EXACT HR+ PET: n = 21; Siemens Biograph 16 PET/CT: n = 16; Philips Gemini-TF PET/CT: n = 19). Urine samples were collected immediately after scan. Activity concentration in the samples was determined in well counters cross-calibrated against the respective scanner. The PET (bladder) to well counter (urine sample) activity concentration ratio was determined.

RESULTS

Activity concentration in the bladder (PET) was systematically lower than in the urine samples (well counter). The patient-averaged PET to well counter ratios for the investigated scanners are (mean ± SEM): 0.881 ± 0.015 (ECAT HR+), 0.898 ± 0.024 (Biograph 16), 0.932 ± 0.024 (Gemini-TF). These values correspond to underestimates by PET of 11.9%, 10.2%, and 6.8%, respectively.

CONCLUSIONS

The investigated PET systems consistently underestimate activity concentration in the bladder. The comparison of urine samples with PET scans of the bladder is a straightforward means for in vivo evaluation of the expectable quantification accuracy. The method might be interesting for multi-center trials, for additional quality assurance in PET and for investigation of PET/MR systems for which clear proof of sufficient quantitative accuracy in vivo is still missing.

Potential of a Cetuximab-based radioimmunotherapy combined with external irradiation manifests in a 3-D cell assay

Targeting epidermal growth factor receptor (EGFR)-overexpressing tumors with radiolabeled anti-EGFR antibodies is a promising strategy for combination with external radiotherapy. In this study, we evaluated the potential of external plus internal irradiation by [(90) Y]Y-CHX-A″-DTPA-C225 (Y-90-C225) in a 3-D environment using FaDu and SAS head and neck squamous cell carcinoma (HNSCC) spheroid models and clinically relevant endpoints such as spheroid control probability (SCP) and spheroid control dose 50% (SCD50 , external irradiation dose inducing 50% loss of spheroid regrowth). Spheroids were cultured using a standardized platform. Therapy response after treatment with C225, CHX-A"-DTPA-C225 (DTPA-C225), [(90) Y]Y-CHX-A"-DTPA (Y-90-DTPA) and Y-90-C225 alone or in combination with X-ray was evaluated by long-term monitoring (60 days) of spheroid integrity and volume growth. Penetration kinetics into spheroids and EGFR binding capacities on spheroid cells were identical for unconjugated C225 and Y-90-C225. Spheroid-associated radioactivity upon exposure to the antibody-free control conjugate Y-90-DTPA was negligible. Determination of the SCD50 demonstrated higher intrinsic radiosensitivity of FaDu as compared with SAS spheroids. Treatment with unconjugated C225 alone did not affect spheroid growth and cell viability. Also, C225 treatment after external irradiation showed no additive effect. However, the combination of external irradiation with Y-90-C225 (1 µg/ml, 24 hr) resulted in a considerable benefit as reflected by a pronounced reduction of the SCD50 from 16 Gy to 9 Gy for SAS spheroids and a complete loss of regrowth for FaDu spheroids due to the pronounced accumulation of internal dose caused by the continuous exposure to cell-bound radionuclide upon Y-90-C225-EGFR interaction.

Automatic volume delineation in oncological PET. Evaluation of a dedicated software tool and comparison with manual delineation in clinical data sets

AIM

Evaluation of a dedicated software tool for automatic delineation of 3D regions of interest in oncological PET.

PATIENTS, METHODS

The applied procedure encompasses segmentation of user-specified subvolumes within the tomographic data set into separate 3D ROIs, automatic background determination, and local adaptive thresholding of the background corrected data. Background correction and adaptive thresholding are combined in an iterative algorithm. Nine experienced observers used this algorithm for automatic delineation of a total of 37 ROIs in 14 patients. Additionally, the observers delineated the same ROIs also manually (using a freely chosen threshold for each ROI) and the results of automatic and manual ROI delineation were compared.

RESULTS

For the investigated 37 ROIs the manual delineation shows a strong interobserver variability of (26.8±6.3)% (range: 15% to 45%) while the corresponding value for automatic delineation is (1.1±1.0)% (range: <0.1% to 3.6%). The fractional deviation of the automatic volumes from the observer-averaged manual ones is (3.7±12.7)%.

CONCLUSION

The evaluated software provides results in very good agreement with observer-averaged manual evaluations, facilitates and accelerates the volumetric evaluation, eliminates the problem of interobserver variability and appears to be a useful tool for volumetric evaluation of oncological PET in clinical routine.

Two or four hour [¹⁸F]FMISO-PET in HNSCC. When is the contrast best?

[¹⁸F]Fluoromisonidazole positron emission tomography (FMISO-PET) is a non invasive imaging technique that can assist detecting intra tumour regions of hypoxia. FMISO-PET evinces comparatively low signal-to-noise-ratio (SNR) and may be acquired dynamically or after different uptake times post injection (p.i.). The aim of this study was to identify, if static images acquired two hours (MISO2) or four hours (MISO4) p.i. reveal higher contrast.

PATIENTS, METHODS

As part of a prospective trial, 23 patients with cancers of the head and neck underwent [¹⁸F]fluorodeoxyglucose (FDG) PET before and during curative radiochemotherapy. Additionally, FMISO-PET studies 2 h and 4 h p.i. were done before treatment and after a mean dose of 11Gy, 23 Gy and 57 Gy during RCT. After coregistration, a dedicated software was used to define the gross tumour volume (GTV) by FDG PET for the primary tumour. This volume was overlaid to the FMISO images and hypoxia within the GTV was determined. The contrast between hypoxia determined by MISO2 and by MISO4 was investigated and analysed with the Wilcoxon-matched-pairs test.

RESULTS

Mean SUVmax in tumours of all examinations was 2.2 (stdev: 0.4, min: 1.3, max: 3.4) after 2 h and 2.4 (stdev: 0.7, min: 1.1, max: 4.4) after 4 h. In the neck musculature the mean SUVmax was 1.5 at both time points and the mean SUVmean decreased from 1.2 after 2 h to 1.1 after 4 h, respectively. These effects resulted in significantly rising contrast ratios from MISO2 to MISO4. The differently defined contrasts revealed significantly higher values for examinations 4 h p.i. (p < 0.002).

CONCLUSION

Data acquisition of [¹⁸F]FMISO should be done 4 h p.i. to gather the optimal contrast, preferably allowing further analysis, e. g. hypoxic sub volume definition for therapy planning.

NOA-08 randomized phase III trial of 1-week-on/1-week-off temozolomide versus involved-field radiotherapy in elderly (older than age 65) patients with newly diagnosed anaplastic astrocytoma or glioblastoma (Methusalem)

LBA2001

Background: The median survival time for elderly patients (pts) with malignant gliomas is in the range of a few months. Radiotherapy (RT) is the standard treatment and superior to best supportive care both with respect to progression-free and overall survival. The benefit derived from surgery and RT is modest, and both treatments are less well tolerated in elderly pts than in the young. The availability of a potentially effective pharmacological agent, temozolomide (TMZ), for malignant glioma, which exhibits a favorable safety profile, necessitated a reconsideration of the widespread therapeutic nihilism with malignant glioma in the elderly.

Methods: The NOA-08 trial of the Neurooncology Working Group (NOA) of the German Cancer Society compared standard postsurgical involved-field RT to a dose of 54-60 Gy, in pts with anaplastic astrocytoma or glioblastoma > 65 ys with a Karnofsky performance score ≥ 60, to TMZ in an one week on/one week off schedule at 100 mg/m2 with dose modification in 25 mg steps in both directions. The primary endpoint was the median survival time (OS) during the follow-up in the 12 months after date of operation. The trial sought to demonstrate the non-inferiority of TMZ compared with RT. Regarding a maximal difference of 25% between both treatment arms in OS as being equivalent, 2 x 206 pts were randomized between May 15, 2005 and Nov 2, 2009 in 22 German and one Suisse sites to provide 80% power to achieve significance at a one-sided level of 0.05. Thirty-nine patients were excluded from the intention-to-treat (ITT) population because no therapy was applied (n=22) or withdrawal of informed consent (n=17).

Results: All histological diagnoses were centrally confirmed. Pts characteristics were balanced between arms in the ITT population (n=373) except for more resections and more anaplastic astrocytomas in the RT arm. The non-inferiority of TMZ was not shown. In contrast, pts in the TMZ arm had an increased risk of death (HR=1.24 [95% CI: 0.94-1.63]) compared to pts in the RT arm. The rate of adverse and serious adverse events was higher in the TMZ arm.

Conclusions: This trial fails to show the non-inferiority of dose-intensified TMZ alone compared with RT alone in the primary treatment of older pts with malignant glioma. Unlike anaplastic glioma in the younger patient population, RT cannot be safely deferred in the treatment of elderly patients with anaplastic astrocytoma or glioblastoma. Whether RT plus TMZ is superior to RT alone, is addressed in the ongoing companion trial conducted by NCIC, EORTC and TROG.

[Table: see text]

[Table: see text]

A new technique for radiolabelling of humic substances

A new method of radiolabelling of humic substances (HS) in the aqueous phase has been developed. Radiolabelling with the short-lived positron-emitter18F was carried outviadiazonium coupling to electron-rich aromatic residues of the humic substances. Labelling yields of up to 75% were obtained after optimization of the synthetic procedure. Introductory experimental steps were performed for testing the labelling stability of the humic substances with ultrafiltration, electrophoretic and chromatographic methods.

[Successful open vascular-surgical supracoeliac anastomosis of a bifurcational prosthesis with simultaneous prosthetomesenteric and renal revascularisation in Leriche's syndrome with high occlusion]

BACKGROUND

Based on an extraordinary case -report on a patient with almost symptomless supramesenteric occlusion of the aorta, the successful management and favourable outcome including almost normalised renal function (in addition to appropriate diagnostic and operative tactics) achieved by a technically challenging vascular-surgical intervention and subsequent intensive medical and nephrological care are described.

RESULTS

In a 49-year-old male patient, a "high" aortic occlusion just below the branching of the coeliac trunk with arterial perfusion of the abdomen and the lower extremities via arterial collaterals from the 4 (th) to 6 (th) intercostal arteries was diagnosed. Both renal arteries were occluded leading to a consecutive renal insufficiency with need for dialysis and renovascularly induced hypertension. However, a residual perfusion of the parenchyma of the left kidney was detectable. Therapeutic measures comprised, after haemodialysis with accompanying antihypertensive medication, open supracoeliac aortobifemoral implantation of a prosthesis, revascularisation of the left renal artery (prosthetic bypass) and prostheticomesenteric bypass implantation. Postoperatively, a reestablished renal perfusion was observed in spite of the preoperatively prolonged lack of appropriate arterial perfusion (last dialysis, 11 (th) POD / discharge, 18 (th) POD). At 3 months postoperatively, the patient reported an increase of his body weight of 8 kg (at 6 months, 20 kg; improved but still elevated laboratory parameters indicating renal insufficiency; RR within normal range). Postinterventional MR angiography revealed a regular perfusion of the bifurcational prosthesis and of the bypasses to the superior mesenteric and left renal arteries.

CONCLUSION

This exemplary case demonstrates impressively the individual therapeutic chances, options and the potential in the diagnostic and therapeutic interdisciplinary management and its combined expertise. The clinical course in this case indicates that the assessment of the arterial blood supply has to be included in the diagnostic of an acute renal insufficiency associated with anuria. If there is a minimal residual perfusion, which might just be sufficient for maintenance of structural integrity, there is a real chance for a restitution of renal function after successful revascularisation.