Feasibility of using glass-bead thermoluminescent dosimeters for radiotherapy treatment plan verification

Objective:

To investigate the feasibility of using glass beads as novel thermoluminescent dosemeters (TLDs) for radiotherapy treatment plan verification.

Methods:

Commercially available glass beads with a size of 1-mm thickness and 2-mm diameter were characterized as TLDs. Five clinical treatment plans including a conventional larynx, a conformal prostate, an intensity-modulated radiotherapy (IMRT) prostate and two stereotactic body radiation therapy (SBRT) lung plans were transferred onto a CT scan of a water-equivalent phantom (Solid Water^®, Gammex, Middleton, WI) and the dose distribution recalculated. The number of monitor units was maintained from the clinical plan and delivered accordingly. The doses determined by the glass beads were compared with those measured by a graphite-walled ionization chamber, and the respective expected doses were determined by the treatment-planning system (TPS) calculation.

Results:

The mean percentage difference between measured dose with the glass beads and TPS was found to be 0.3%, −0.1%, 0.4%, 1.8% and 1.7% for the conventional larynx, conformal prostate, IMRT prostate and each of the SBRT delivery techniques, respectively. The percentage difference between measured dose with the ionization chamber and glass bead was found to be −1.2%, −1.4%, −0.1%, −0.9% and 2.4% for the above-mentioned plans, respectively. The results of measured doses with the glass beads and ionization chamber in comparison with expected doses from the TPS were analysed using a two-sided paired t-test, and there was no significant difference at p < 0.05.

Conclusion:

It is feasible to use glass-bead TLDs as dosemeters in a range of clinical plan verifications.

Advances in knowledge:

Commercial glass beads are utilized as low-cost novel TLDs for treatment-plan verification.     

Central nervous system abnormalities in Fanconi anaemia: patterns and frequency on magnetic resonance imaging

Objective:

Fanconi anaemia (FA) is an inherited disease associated with congenital and developmental abnormalities resulting from the disruption of a multigenic DNA damage response pathway. This study aimed to define the MRI appearances of the brain in patients with FA in correlation with their genetic and clinical features.

Methods:

A review of the brain MRI in 20 patients with FA was performed. Pituitary size and frequencies of the radiological findings of individuals with FA and age-matched controls were determined.

Results:

Abnormalities were identified in 18 (90%) patients with FA, the commonest being a small pituitary (68%, p < 0.01 females and p < 0.001 males). In five cases (25%, p = 0.02), the pituitary morphology was also abnormal. Posterior fossa abnormalities were seen in six cases (30%, p = 0.01) including Chiari I malformation (n = 3), Dandy–Walker variant (n = 2) and cerebellar atrophy (n = 2). Six patients (30%, p = 0.01) had morphological structural variation of the corpus callosum (CC).

Conclusion:

The incidence of central nervous system (CNS) abnormalities in FA is higher than previously reported, with a midline predominance that points to impact in the early stages of CNS development. MRI brain imaging is important for endocrine assessment and pre-transplant evaluation and can make an important contribution to clinical decision-making.

Advances in knowledge:

The incidence of brain structural abnormalities in FA is higher than previously reported, with abnormalities of the posterior fossa, CC and pituitary being common. There is an association with gender and reduction in pituitary size which does not strongly correlate with biochemically evident endocrine abnormality.     

Clinical outcomes in patients on preinjury ibuprofen with traumatic brain injury

Background

The aim of our study was to evaluate the clinical outcomes in patients on preinjury Ibuprofen with traumatic brain injury.

Methods

We performed a 2-year analysis of all patients on prehospital Ibuprofen with traumatic brain injury and intracranial hemorrhage. Patients on preinjury Ibuprofen were matched using propensity score matching to patients not on Ibuprofen in a 1:2 ratio for age, Glasgow Coma Scale, head-abbreviated injury scale, injury severity score, International Normalized Ratio, and neurologic examination. Outcome measures were progression on repeat head computed tomography (RHCT) and neurosurgical intervention.

Results

A total of 195 matched (Ibuprofen 65, no-Ibuprofen 130) patients were included. There was no difference in the progression on RHCT (Ibuprofen 18% vs no-Ibuprofen 24%; P = .50). The neurosurgical intervention rate was 18.9% (n = 37). There was no difference for need for neurosurgical intervention (26% vs 16%; P = .10) between the 2 groups.

Conclusions

In a matched cohort of trauma patients, preinjury Ibuprofen use was not associated with progression of initial intracranial hemorrhage and the need for neurosurgical intervention. Preinjury use of Ibuprofen as an independent variable should not warrant the need for a routine RHCT scan.     

The effect of antecolic versus retrocolic reconstruction on delayed gastric emptying after classic non–pylorus-preserving pancreaticoduodenectomy

Background

Delayed gastric emptying (DGE) after pancreaticoduodenectomy increases length of hospital stay and costs, and may be influenced by surgical techniques.

Methods

We retrospectively compared 400 patients with antecolic gastrojejunostomy with 400 patients with retrocolic gastrojejunostomy for the occurrence of DGE.

Results

The prevalence of DGE was 15% in the antecolic group and 21% in the retrocolic group (P = .021), and median length of stay was shorter for the former (8 vs 10 days, P = .001). The difference was statistically significant with grade A DGE (9% vs 14%, P = .038), but not B or C. In a multivariate analysis, DGE was influenced by retrocolic reconstruction, as well as older age, chronic pancreatitis, preoperative bilirubin level, a history of previous upper abdominal surgery, and postoperative pancreatic fistula.

Conclusions

An antecolic gastrojejunostomy for classic non–pylorus-preserving pancreaticoduodenectomy is associated with a lower incidence of mild DGE (grade A) and a shorter length of stay.