OS07.2.A Evaluation of Intraoperative Surgical Adjuncts and Resection of Glioblastoma (ELISAR GB): A UK and Ireland multicentre, prospective observational cohort study

Background

Despite operative and adjuvant therapies, glioblastoma remains incurable, with the extent of resection being one of few treatments that can improve survival. To improve resection, operative adjuncts are used, with neuronavigation and 5-aminolevulinic acid (5-ALA) recommended as a standard of care in those aimed for maximal safe resection. Despite the standards, meta-analysis concluded that the impact of 5-ALA on the extent of surgical resection is of low quality due to bias in reporting tumour location and additional image guidance used, factors impacting on extent of resection as well as short-term neurological outcomes being uncertain. Therefore we aimed to evaluate the availability and use of 5-ALA and other adjuncts and compare surgical outcomes of 5-ALA-guided versus non-5-ALA-guided resections.

Material and Methods

A multicenter prospective observational cohort study was conducted across 27 out of 31 available centres in the UK and Ireland from 6 January until 19 March 2020. Inclusion criteria included adults with first diagnosis, supratentorial glioblastoma undergoing resection. Primary outcomes included: i) the availability and use of surgical adjuncts and ii) complete resection of enhancing tissue (CRET). Secondary outcomes included adverse events, new onset of postoperative neurological deficit and post-operative neurological function. Descriptive and inferential statistics were used for analysis with a p-value <0.05 deemed significant.

Results

232 consecutive cases were identified. 142/232 cases were aimed for maximal safe resection subsequently divided into 5-ALA-guided (n=92) versus non-5-ALA-guided (n=50) resections. 5-ALA and neuronavigation were available across all centres. Neuronavigation and 5-ALA were used in 91% (n=129/142) and 65% (n=92/142) of cases aimed for maximal safe resection whereas 83% (n=75/90) and 49% (n=44/90) for debulk surgery. 35 unique combinations of surgical adjuncts were used in 232 operations. 5-ALA-guided resection yielded a higher percentage of CRET than without (55% versus 28%, p < 0.01). The two groups showed no difference in adverse events (p=0.98), new onset of neurological deficit (p=0.88) nor neurological function (p=0.7). A logistic regression analysis showed that 5-ALA was an important predictor of CRET regardless of additional adjuncts used (OR 2.4, CI 0.96-5.97, P = 0.05), tumour location and molecular characterisation (OR 3.48, CI 1.61-7.51, P <0.01).

Conclusion

Firstly, we showed that 5-ALA is not always used for glioblastoma aimed for CRET. Secondly, we report a great heterogeneity of adjuncts used for resection, possibly explained by a lack of high-quality evidence and surgeon training. Thirdly we demonstrate that 5-ALA-guided resection leads to higher percentage of CRET regardless of other adjuncts used, tumour location and molecular characterisation.

P07.06.B The Impact of Using Intraoperative Ultrasound on Surgical Resection of High-Grade Glioma: A Systematic Review and Meta-Analysis

Background

Despite operative and adjuvant therapies, high-grade glioma (HGG) remains incurable, with the extent of surgical resection being one of the modalities that can improve patient survival. Enabling maximal safe and minimising post-operative neurological morbidity is a key aim of surgical resection. Numerous intraoperative surgical adjuncts are used at surgery and intraoperative ultrasound (IoUS), is one such adjunct. IoUS is a cost-effective, easy to use, repeatable surgical adjunct, safe for the patient and potentially available in all centres. Although it’s commonly used, no up to date systematic review exists collating and quantifying the level of evidence, delineating its impact on the extent of surgical resection.

Material and Methods

A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The study was registered with the PROSPERO database (CRD42022300034). Keywords across Medline/PubMed and Embase between 1996 and November 2021 were used. We included articles with adult supratentorial, histopathologically confirmed HGG patients aimed for resection, evaluating the correlation of IoUS use and gross-total resection (GTR). Meta-analyses were conducted according to the statistical heterogeneity between the studies using the Open Meta Analyst software.

Results

2942 articles were identified of which 16 were qualitative assessed and 10 used for quantitative meta-analysis. In qualitative assessment, a mean 4.63/8 Newcastle-Ottawa-Scale score was found for studies with no cohorts (no use of IoUS) and a mean score of 6/9, for studies including exposed versus non-exposed cohorts. The RCT was of moderate quality according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool. A pooled analysis across 10 studies of HGG aimed for resection with the use of IoUS, led to GTR achieved in 168/365 cases, resulting in an overall GTR rate of 51.1% (95% CI, 33.9%-68.3%, p<0.001), with great heterogeneity across studies (93.02% p<0.001). In a subgroup meta-analysis of 3 studies of HGG aimed for complete resection only, GTR was achieved in 43/62 cases, yielding a 72.7% GTR rate (95% CI 41.6%-100%, p<0.001) with significant heterogeneity across studies (I2 92.1%, p<0.001). In 4 case-controlled studies, a total of 43.6% (48/110) GTR rate was achieved when IoUS was used versus 24.7% (65/263) when IoUS was not used, resulting in an odds ratio = 2.009 (95% CI 1.157-3.490, p <0.001) for achieving GTR.

Conclusion

The meta-analysis showed a high GTR rate (72.7%) when HGG were aimed for complete resection and a two-fold probability of achieving GTR when IoUS is used than not used.

Radiation Exposure in Bone Densitometry

This article provides an overview of the literature regarding the magnitude of radiation exposure associated with the current radiologic methods used in patients with suspected osteoporosis. The use of X-ray-based techniques for the detection and monitoring of osteoporosis has increased over the last few decades. Dual-energy X-ray absorptiometry is the most common method, used worldwide for the assessment of osteoporosis, and it may be applied at several skeletal sites. Quantitative computed tomography comprises an alternative validated technique, increasingly used for skeleton assessment. Although radiation doses from methods applied for the management of osteoporosis are low, compared with other radiologic methods, special attention should be paid to justify and optimize each procedure, taking into consideration all radiation protection measures. Dose optimization, including dose reduction techniques and low-dose protocols, is of paramount importance, even for low-dose examinations, to achieve the minimum radiation burden to the exposed patients and personnel.

Data and methods to estimate fetal dose from fluoroscopically guided prophylactic hypogastric artery balloon occlusion

PURPOSE

To provide data for estimation of fetal radiation dose (DF) from prophylactic hypogastric artery balloon occlusion (HABO) procedures.

METHODS

The Monte-Carlo-N-particle (MCNP) transport code and mathematical phantoms representing a pregnant patient at the ninth month of gestation were employed. PA, RAO 20° and LAO 20° fluoroscopy projections of left and right internal iliac arteries were simulated. Projection-specific normalized fetal dose (NFD) data were produced for various beam qualities. The effects of projection angle, x-ray field location relative to the fetus, field size, maternal body size, and fetal size on NFD were investigated. Presented NFD values were compared to corresponding values derived using a physical anthropomorphic phantom simulating pregnancy at the third trimester and thermoluminescence dosimeters.

RESULTS

NFD did not considerably vary when projection angle was altered by ±5°, whereas it was found to markedly depend on tube voltage, filtration, x-ray field location and size, and maternal body size. Differences in NFD < 7.5% were observed for naturally expected variations in fetal size. A difference of less than 13.5% was observed between NFD values estimated by MCNP and direct measurements.

CONCLUSIONS

Data and methods provided allow for reliable estimation of radiation burden to the fetus from HABO.

Pediatric radiation dose and risk from bone density measurements using a GE Lunar Prodigy scanner

Effective radiation doses associated with bone mineral density examinations performed on children using a GE Lunar Prodigy fan-beam dual-energy X-ray absorptiometry (DXA) scanner were found to be comparable to doses from pencil-beam DXA devices, i.e., lower than 1 μSv. Cancer risks associated with acquisitions obtained in this study are negligible.

INTRODUCTION

No data were found in the literature on radiation doses and potential risks following pediatric DXA performed on GE Lunar DXA scanners. This study aimed to estimate effective doses and associated cancer risks involved in pediatric examinations performed on a GE Lunar Prodigy scanner.

METHODS

Four physical anthropomorphic phantoms representing newborn, 1-, 5-, and 10-year-old patients were employed to simulate DXA exposures. All acquisitions were carried out using the Prodigy scanner. Dose measurements were performed for spine and dual femur using the phantoms simulating the 5- and 10-year-old child. Moreover, doses associated with whole-body examinations were measured for the four phantoms used in the current study.

RESULTS

The gender-average effective dose for spine and hip examinations were 0.65 and 0.36 μSv, respectively, for the phantom representing the 5-year-old child and 0.93 and 0.205 μSv, respectively, for the phantom representing the 10-year-old child. Effective doses for whole-body examinations were 0.25, 0.22, 0.19, and 0.15 μSv for the neonate, 1-, 5-, and 10-year old child, respectively. The estimated lifetime cancer risks were negligible, i.e., 0.02-0.25 per million, depending on the sex, age, and type of DXA examination. A formula is presented for the estimation of effective dose from examinations performed on GE Lunar Prodigy scanners installed in other institutions.

CONCLUSIONS

The effective doses and potential cancer risks associated with pediatric DXA examinations performed on a GE Lunar Prodigy fan-beam scanner were found to be comparable to doses and risks reported from pencil-beam DXA devices.

Subclavian vein flexible guidewire knotting. A potential serious complication in hemodialysis patients

BACKGROUND

Complications after subclavian vein catheterization are well-documented in the literature. The purpose of this article is to present a case of a rare and potential serious complication of flexible guidewire knotting in subclavian vein catheterization in a hemodialysis patient.

METHOD

A 72 year-old woman on hemodialysis due to diabetes has had left upper extremity arteriovenous fistula (AV-F) thrombosed on the scheduled hemodialysis day. A right subclavian vein catheterization for hemodialysis was decided and attempted, that ended up with a flexible guidewire knotting.

RESULTS

The flexible guidewire was splinted with the Kit's dilator and after great effort, under radioscopic control the knotting was managed to be unknotted and the guidewire removed.

CONCLUSIONS

Our case suggests that a rare and potential serious complication of subclavian vein catheterization for hemodialysis can be successfully managed with appropriate approach and skillful maneuvers.

Relief of the pain of unresectable carcinoma of pancreas by chemical splanchnicectomy during laparotomy

Peroperative chemical splanchnicectomy using 5% phenol in almond oil is an effective method of relieving pain in carcinoma of the pancreas. Forty-nine patients have been treated, 41 having suffered preoperative pain. Five patients died within 10 days of operation, but in no case was the splanchnicectomy a contributing factor. Of the 37 patients who had suffered pain preoperatively and then survived 10 days or more after operation, 30 (81%) experienced relief of pain and in 26 (70%) this relief persisted till death. There was no statistically significant difference in survival patterns of these splanchnicectomy patients and a comparable group of patients with pancreatic carcinoma treated in a similar way but without splanchnicectomy.