Thoracic 99mTc-MAA accumulations due to aberrant arteries originating from the phrenic artery / Acumulación torácica de 99mTc-MAA debido a arterias aberrantes procedentes de la arteria frénica

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Residual activity after radioembolization of liver tumours with 90Y resin microspheres. A safe calculation method.

UNLABELLED: The actual number of resin microspheres is approximately 30-60 times higher than glass microspheres per 3 GBq vial. Thus, radioembolization (RE) with resin microspheres exerts an embolization effect besides the radiation effect. This embolization effect can occasionally cause early back flow of the microspheres before application of the entire calculated dose. To avoid these adverse side effects, RE has to be terminated at an earlier time point. Measurement of the residual activity in the delivery box, which includes the v-vial, tube and catheter, to calculate the achieved target dose is often challenging. The aim of the current study was to establish a post-RE measurement method comparable to the glass microspheres method without unnecessary radiation exposure to the staff and risk of contamination. METHODS: Two different measurements were performed. First, total radioactivity in the shipping vial was measured in an ion chamber and then it was put in the delivery box and the radiation was measured from a 30 cm distance from the centre of the box with a dosimeter. The required radioactivity was then transferred to the v-vial, and the shipping vial was measured again. After that, the v-vial was measured from the same distance from the centre of the box with dosimeter. RESULTS: Altogether 62 times the shipping vial with different activities were measured with a significant positive correlation between the amount of the activity measured in the iron chamber and the radiation dose, measured with dosimeter (r² = 0.98; p< 0.001). There was also a strong positive correlation between these measurements of the v-vial (r² = 0.98; p< 0.001). CONCLUSION: With measurement of the residual activity in the delivery box using a dosimeter the percentage of the whole injected activity can be easily calculated. This facilitates the calculation of the actual, achieved target and non-target dose in those cases, where therapy had to be stopped because of eminent flow reversal or obstruction.

Microwave, infrared-microwave double resonance, and theoretical studies of C2H4···H2S complex.

In this manuscript, rotational spectra of four new isotopologues of the S-H···π bonded C2H4···H2S complex, i.e., C2D4···H2S, C2D4···D2S, C2D4···HDS, and (13)CCH4···H2S have been reported and analyzed. All isotopologues except C2D4···HDS show a four line pattern whereas a doubling of the transition frequencies was observed for C2D4···HDS. These results together with our previous report on the title complex [M. Goswami, P. K. Mandal, D. J. Ramdass, and E. Arunan, Chem. Phys. Lett. 393(1-3), 22-27 (2004)] confirm that both subunits (C2H4 and H2S) are involved in large amplitude motions leading to a splitting of each rotational transition to a quartet. Further, the results also confirm that the motions which are responsible for the observed splittings involve both monomers. Molecular symmetry group analysis, considering the interchange of equivalent H atoms in H2S and C2H4 could explain the observed four line pattern and their intensities in the microwave spectrum. In addition, hydride stretching fundamentals of the complex were measured using coherence-converted population transfer Fourier Transform Microwave-infrared (IR-MW double resonance) experiments in the S-H and C-H stretch regions. Changes in the tunneling splittings upon vibrational excitation are consistent with the isotopic dependence of pure rotational transitions. A complexation shift of 2.7-6.5 cm(-1) has been observed in the two fundamental S-H stretching modes of the H2S monomer in the complex. Vibrational pre-dissociation in the bound S-H stretch has been detected whereas the instrument-limited line-shapes in other S-H and C-H stretches indicate slower pre-dissociation rate. Some local perturbations in the vibrational spectra have been observed. Two combination bands have been observed corresponding to both the S-H stretching fundamentals and what appears to be the intermolecular stretching mode at 55 cm(-1). The tunneling splitting involved in the rotation of C2H4 unit has been deduced to be 1.5 GHz from the IR-MW results. In addition, ab initio barrier heights derived for different motions of the monomers support the experimental results and provide further insight into the motions causing the splitting.

Osseous metastases of gastro-enteropancreatic neuroendocrine tumours. Diagnostic value of intra-therapeutic 177Lu-octreotate imaging in comparison with bone scintigraphy.

AIM: Peptide receptor radionuclide therapy with 177Lu-octreotate is an effective treatment option for metastatic gastroenteropancreatic neuroendocrine tumors (GEP NET) and allows intratherapeutic imaging through a 177Lu-octreotate scan (LuS). The diagnostic value of this treatment scan is not yet established. This study aims to compare the sensitivity of LuS and bone scintigraphy (BS) regarding bone metastases and investigate potential implications of functional imaging results. PATIENTS, METHODS: We retrospectively analyzed 29 consecutive GEP NET patients with bone metastases and baseline BS treated with 177Lu-octreotate. A semi-quantitative scoring system was used for the comparative evaluation. Treatment outcome (time-to-progression of bone metastases) was correlated with the intra-individual imaging discrepancy (Kaplan-Meyer curves, log-rank test, p < 0.05). RESULTS: In 19 of 29 patients (65.5%) LuS was superior (LuS > BS), whereas in 10 patients (34.5%) both modalities were comparable. BS showed no additional (LuS-negative) metastatic bone lesions in our cohort. None of the investigated baseline characteristics was associated with imaging discrepancy. On the other hand, functional imaging discrepancy had no impact on treatment response (p = 0.43) or time-to-progression (p = 0.92). CONCLUSIONS: Intra-therapeutic 177Lu-octreotate imaging is superior over bone scintigraphy for detection of bone metastases in GEP NET. BS may help to distinguish osseous from non-osseous localization. The presence of an osteoblastic correlate in BS seems to have no impact on therapeutic outcome.