Radiation exposure using the O-arm<Superscript>®</Superscript> surgical imaging system

Purpose

This study was conducted to characterise the O-arm^® surgical imaging system in terms of patient organ doses and medical staff occupational exposure during three-dimensional thoracic spine and pelvic examinations.

Methods

An anthropomorphic phantom was used to evaluate absorbed organ doses during a three-dimensional thoracic spine scan and a three-dimensional pelvic scan with the O-arm^®. Staff occupational exposure was evaluated by constructing an ambient dose cartography of the operating theatre during a three-dimensional pelvic scan as well as using an anthropomorphic phantom to simulate the O-arm^® operator.

Results

Patient organ doses ranged from 30 ± 4 μGy to 20.0 ± 3.0 mGy and 4 ± 1 μGy to 6.7 ± 1.0 mGy for a three-dimensional thoracic spine and pelvic examination, respectively. For a single three-dimensional acquisition, the maximum ambient equivalent dose at 2 m from the iso-centre was 11 ± 1 μSv.

Conclusion

Doses delivered to the patient during a three-dimensional thoracic spine image acquisition were found to be significant with the O-arm^®, but lower than those observed with a standard computed tomography examination. The detailed dose cartography allows for the optimisation of medical staff positioning within the operating theatre while imaging with the O-arm^®.

     

Medical students call for national standards in anatomical education

The diminishing number of hours dedicated to formal instruction in anatomy has led to a debate within medical education as to the level required for safe clinical practice. We provide a review of the current state of anatomical education in Australian medical schools and state the case for national standards. In light of the review presented, council members of the Australian Medical Students' Association voted to affirm that consideration should be given to developing undergraduate learning goals for anatomy, providing a codified medical student position on the teaching of anatomy in Australian medical schools. Crucially, the position states that time‐intensive methods of instruction such as dissection should be a rite of passage for medical students in the absence of evidence demonstrating the superiority of modern teaching methods. We believe the bodies with a vested interest in the quality of medical graduates, namely the Australian Medical Council, Medical Deans Australia & New Zealand, and the postgraduate colleges should collaborate and develop clear guidelines that make explicit the core knowledge of anatomy expected of medical graduates at each stage of their career with a view to safe clinical practice. In addition, Australian universities have a role to play in conducting further research into contemporary learning styles and the most efficacious methods of delivering anatomical education.     

Prognostic meaning of neutrophil to lymphocyte ratio (NLR) and lymphocyte to monocyte ration (LMR) in newly diagnosed Hodgkin lymphoma patients treated upfront with a PET-2 based strategy

Recent reports identify NLR (the ratio between absolute neutrophils counts, ANC, and absolute lymphocyte count, ALC), as predictor of progression-free survival (PFS) and overall survival (OS) in cancer patients. We retrospectively tested NLR and LMR (the ratio between absolute lymphocyte and monocyte counts) in newly diagnosed Hodgkin lymphoma (HL) patients treated upfront with a PET-2 risk-adapted strategy. NLR and LMR were calculated using records obtained from the complete blood count (CBC) from 180 newly diagnosed HL patients. PFS was evaluated accordingly to Kaplan-Meier method. Higher NLR was associated to advanced stage, increased absolute counts of neutrophils and reduced count of lymphocytes, and markers of systemic inflammation. After a median follow-up of 68 months, PFS at 60 months was 86.6% versus 70.1%, respectively, in patients with NLR?≥?6 or NLR?<?6. Predictors of PFS at 60 months were PET-2 scan (p?<?0.0001), NLR?≥?6.0 (p?=?0.02), LMR?<?2 (p?=?0.048), and ANC (p?=?0.0059) in univariate analysis, but only PET-2 was an independent predictor of PFS in multivariate analysis. Advanced-stage patients (N?=?119) were treated according to a PET-2 risk-adapted protocol, with an early switch to BEACOPP regimen in case of PET-2 positivity. Despite this strategy, patients with positive PET-2 still had an inferior outcome, with PFS at 60 months of 84.7% versus 40.1% (negative and positive PET-2 patients, respectively, p?<?0.0001). Independent predictors of PFS by multivariate analysis were PET-2 status and to a lesser extend NLR in advanced stage, while LMR maintained its significance in early stage. By focusing on PET-2 negative patients, we found that patients with NLR?≥?6.0 or LMR?<?2 had an inferior outcome compared to patients with both ratios above the cutoff (78.7 versus 91.9 months, p?=?0.01). We confirm NLR as predictor of PFS in HL patients independently from stage at diagnosis. Integration of PET-2 scan, NLR and LMR can result in a meaningful prognostic system that needs to be further validated in prospective series including patients treated upfront with PET-2 adapted-risk therapy.     

Autocrine and paracrine growth control by granulocyte-monocyte colony- stimulating factor of acute lymphoblastic leukemia cells

Blast colony assays were performed on freshly obtained bone marrow samples from 19 newly diagnosed or relapsed children with acute lymphoblastic leukemia (ALL) of B lineage to determine the effect of added granulocyte-monocyte colony-stimulating factor (GM-CSF). Of the 19 marrow samples tested, 7 responded to GM-CSF with a mean increase in ALL blast colonies of 346%. Blast cells from one of the responders chosen for flow cytometric study showed expression of GM-CSF receptors on 38% of cells. These findings prompted us to establish five ALL cell lines of diverse phenotypes to examine the expression of GM-CSF and GM- CSF receptor genes in human leukemia, and to determine the role of GM- CSF in autocrine and paracrine growth control of ALL cells. One line, termed G2, manifested a GM-CSF-mediated autocrine pattern of cell growth with the following features: G2 blast colony growth in a serum- free system without added growth factor was density dependent; exogenous GM-CSF augmented G2 colony formation when the cells were seeded at low density; G2 cells constitutively expressed mRNA for GM- CSF and GM-CSF receptor; G2 cells also produced and secreted measurable amounts of GM-CSF into cell culture supernatant; and, monoclonal anti- GM-CSF antibodies abolished G2 colony growth when added to cultures with cells seeded at low density without growth factors. Of the other four ALL cell lines, three expressed mRNA for GM-CSF receptor and responded in vitro to added GM-CSF with increased blast colony growth; however, none of these four cell lines expressed mRNA for constitutive production of GM-CSF. A fifth ALL cell line lacked receptors for GM-CSF and did not respond in clonogenic assays to added GM-CSF. Thus, a bioregulator of normal hematopoiesis plays a central role in autocrine growth control of G2 ALL cells, and an important paracrine growth- promoting role in three of four other ALL cell lines.     

Current Concepts in Laparoscopic Liver Surgery

Laparoscopic liver surgery is currently acknowledged to be a safe and effective approach for the treatment of a variety of benign and malignant hepatic lesions. Its wider adoption was delayed by lack of experience, unavailability of suitable laparoscopic equipment, fear of uncontrollable intraoperative adverse events and the perceived oncological inadequacy of the approach. Over the years all these obstacles were overcome, and increasing numbers of studies documented the safety and efficacy of the procedure, with beneficial short-term results and long-term outcome comparable with that of the traditional open approach. This review presents the current knowledge on the indications, advantages, and short- and long-term outcomes of laparoscopic liver resection for a variety of liver lesions.     

Glycogen Storage Disease Diagnosed in Adults

Glycogen storage diseases are usually identified in childhood.We present the clinical, biochemical and histological featuresof 10 patients first diagnosed in adult life. Five had glycogenstorage disease type 1a, one type 1e, two type IX, and in twopatients there were previously unreported abnormalities of hepaticglucose-6-phosphatase system activity. Of the latter, one patienthad an inhibitor of liver glucose-6-phosphatase (pseudo-1b glycogenstorage disease) the other having abnormal glucose-6-phosphataseactivity and microsomal pyrophosphate transport. A glucagontest is suggested as a useful screening procedure. Glycogenstorage disease should be considered in adults with symptomssuggesting hypoglycaemia.