Radiopaque drug-eluting embolisation beads as fiducial markers for stereotactic liver radiotherapy.

OBJECTIVE: To determine the feasibility of using radiopaque (RO) beads as direct tumour surrogates for image-guided radiotherapy (IGRT) in patients with liver tumours after transarterial chemoembolisation (TACE). METHODS: A novel vandetanib-eluting RO bead was delivered via TACE as part of a first-in-human clinical trial in patients with either hepatocellular carcinoma or liver metastases from colorectal cancer. Following TACE, patients underwent simulated radiotherapy imaging with four-dimensional computed tomography (4D-CT) and cone-beam CT (CBCT) imaging. RO beads were contoured using automated thresholding, and feasibility of matching between the simulated radiotherapy planning dataset (AVE-IP image from 4D data) and CBCT scans assessed. Additional kV, MV, helical CT and CBCT images of RO beads were obtained using an in-house phantom. Stability of RO bead position was assessed by comparing 4D-CT imaging to CT scans taken 6-20 days following TACE. RESULTS: Eight patients were treated and 4D-CT and CBCT images acquired. RO beads were visible on 4D-CT and CBCT images in all cases and matching successfully performed. Differences in centre of mass of RO beads between CBCT and simulated radiotherapy planning scans (AVE-IP dataset) were 2.0 mm mediolaterally, 1.7 mm anteroposteriorally and 3.5 mm craniocaudally. RO beads in the phantom were visible on all imaging modalities assessed. RO bead position remained stable up to 29 days post TACE. CONCLUSION: RO beads are visible on IGRT imaging modalities, showing minimal artefact. They can be used for on-set matching with CBCT and remain stable over time. ADVANCES IN KNOWLEDGE: The role of RO beads as fiducial markers for stereotactic liver radiotherapy is feasible and warrants further exploration as a combination therapy approach.

Current status of stereotactic ablative body radiotherapy in the UK: six years of progress.

OBJECTIVE: To update the 2012 UK stereotacticablative radiotherapy (SABR) Consortium survey and assess the development of SABR services across the UK over the past 6 years. Use the results to share practice and continue to drive forward technique development, aid standardization and by highlighting issues, improve access to SABR services and trials across the UK. METHODS: In January 2018, an online questionnaire was sent by the UK SABR Consortium to 65 UK radiotherapy institutions covering current service provision and collecting data on immobilization, motion management, scanning protocols, target/OAR delineation, planning, image-guidance, quality assurance and future plans. RESULTS: 50 (77%) institutions responded, 38 ( vs 15 in 2012) indicated they had an active SABR programme with the remaining 12 centres intending to develop a SABR programmeDocumented changes include the development of Linac delivered SABR to non-lung sites, an increase in centres using abdominal compression (14 vs 2) and the introduction of four-dimensional cone beam CBCT. Current practice is broadly in line with UK SABR Consortium and European guidelines. CONCLUSION: This 2018 survey shows a welcome increase in SABR provision, surpassing 2012 projections. However, it is clear that the UK SABR program needs to continue to expand to ensure that patients with oligometastatic disease have access and SABR for early stage lung cancer is available in all centres. Updated guidance that addresses variability in target delineation, image guidance and reduces patient specific quality assurance is warranted. ADVANCES IN KNOWLEDGE: Documented progress of UK SABR across all treatment sites over the last six years, barriers to implementation and future plans.

A generalized framework unifying image registration and respiratory motion models and incorporating image reconstruction, for partial image data or full images.

Surrogate-driven respiratory motion models relate the motion of the internal anatomy to easily acquired respiratory surrogate signals, such as the motion of the skin surface. They are usually built by first using image registration to determine the motion from a number of dynamic images, and then fitting a correspondence model relating the motion to the surrogate signals. In this paper we present a generalized framework that unifies the image registration and correspondence model fitting into a single optimization. This allows the use of 'partial' imaging data, such as individual slices, projections, or k-space data, where it would not be possible to determine the motion from an individual frame of data. Motion compensated image reconstruction can also be incorporated using an iterative approach, so that both the motion and a motion-free image can be estimated from the partial image data. The framework has been applied to real 4DCT, Cine CT, multi-slice CT, and multi-slice MR data, as well as simulated datasets from a computer phantom. This includes the use of a super-resolution reconstruction method for the multi-slice MR data. Good results were obtained for all datasets, including quantitative results for the 4DCT and phantom datasets where the ground truth motion was known or could be estimated.

Lipids and essential fatty acids in patients presenting with self-harm.

BACKGROUND: Low cholesterol has been reliably demonstrated in people who self-harm. AIMS: To determine whether people who self-harm also have low levels of essential fatty acids (EFAs) and to examine associations between the EFAs and serotonergic function. METHOD: Depression, impulsivity and suicidal intent were measured in patients with self-harm (n=40) and matched controls, together with plasma lipids and EFAs. Platelet serotonergic studies were carried out in a subgroup (n=27). RESULTS: Patients with self-harm had significantly more pathology on all psychometric measures, lower mean total cholesterol levels (4.18 (s.d.=0.93) v. 4.87 (s.d.=0.83) mmol/l, P=0.003) and lower mean total EFA levels (89. 5 (15.6) v.103.7 (17.1) microg/ml, P=0.0001) than controls after adjustment for confounding variables. Total n-3 and n-6 EFA levels were also significantly lower. Impulsivity and depression scores were significantly inversely correlated with both n-6 EFAs and n-3 EFAs, but were not associated with total or low-density lipoprotein cholesterol levels. Platelet serotonergic measures did not differ between groups, and were not related to psychobiological measures. CONCLUSIONS: Lower plasma EFA levels combined with low cholesterol concentrations were associated with self-harm as well as impulsivity and affect. This was not related to platelet serotonergic measures.

Fetal cardiac troponin I in relation to intrapartum events and umbilical artery pH.

The objective of this study was to measure fetal cardiac troponin I in umbilical artery blood in relation to intrapartum events and umbilical artery pH. Umbilical artery blood samples were obtained after delivery from 110 infants and cardiac troponin I was measured. The onset of labor, mode of delivery, presence of meconium, and umbilical artery pH were examined in relation to cardiac troponin I. The median cardiac troponin I level was 0.03 ng/mL (range, 0.03 to 0.881 ng/mL). Neonates with a cardiac troponin I level above the normal range had a lower umbilical artery pH when compared with those neonates with a normal cardiac troponin I level (p = 0.005). No relationship between the following parameters and cardiac troponin I was observed: gestational age, parity, presence of labor, meconium staining, mode of delivery, birth weight, and Apgar scores. Fetal cardiac troponin I shows little variation at birth. Increased levels of cardiac troponin I are associated with a lower umbilical artery pH.

Fetal cortisol in relation to labour, intrapartum events and mode of delivery.

We set out to measure fetal cortisol in the human umbilical vein in relation to onset of labour, intrapartum complications and mode of delivery. Umbilical cord venous samples were obtained after delivery from 98 infants and serum total cortisol was measured. The onset of spontaneous labour, induction of labour, elective caesarean section, spontaneous vaginal delivery, emergency caesarean section in labour, instrumental delivery, the presence of meconium staining of the liquor and umbilical artery pH were examined in relation to serum fetal cortisol. Spontaneous onset of labour, mode of delivery, meconium staining of the liquor and gestational age were independent predictors of umbilical venous cortisol levels. Those infants delivered by elective caesarean section had the lowest cortisol levels, while the highest levels were recorded in those infants following instrumental delivery. Fetal cortisol is significantly elevated in association with spontaneous human parturition and is highest Its among babies born by instrumental delivery.