1st metatarso-phalangeal joint arthroplasty with ROTO-glide implant

BACKGROUND

Total joint replacement of the 1st metatarso-phalangeal Joint (MTPJ) has been controversial as arthrodesis remains a good option for patients with end stage 1st MTPJ arthritis. We present a multi centre service evaluation of the ROTO-glide device METHODS: 33 ROTO-glide procedures were carried out in 30 patients across 7 sites within the UK. Exclusion criteria - hallux valgus and arthritis, age below 45 years and over 80 years, inflammatory joint disease. Patient assessed pre and post operatively with AOFAS and Oxford forefoot (MOXFQ) scores and plain radiographs. All patients carried out the same post operative protocol RESULTS: Average age at patients was 58.6 years (45-77). Follow up average was 16.9 months (12-29). Pre-op AOFAS scores average 41.4 (17-67) and post op average 76 (29-100) and the MOXFQ summary index decreased from an average of 43 (20-64) pre op to an average of 17 (0-51) post op. Average total range of motion pre operatively was 32° and post operatively was 61°. There were 2 post operative complications but no revisions were necessary.

CONCLUSIONS

The early results of this multi centre service evaluation of the ROTO-glide 1st MTPJ replacement support its continued use and evaluation of the prosthesis further.

[Full thickness resection device (FTRD). Experience and outcome for benign neoplasms of the rectum and colon]

BACKGROUND

The diagnostic validity of a full-thickness resection is higher compared to endoscopic mucosal resection (EMR) or endoscopic mucosal dissection (ESD). Whereas transanal endoscopic microsurgery techniques (TEM, TAMIS) are established therapeutic procedures in the rectum no established and safe minimally invasive or endoscopic procedure exists in the colon.

AIM

In this study the novel endoscopic full thickness resection device (FTRD, Ovesco, Germany) was investigated concerning success rates with histologically proven full thickness resections, R0 status as well as patient and device safety for the rectum and colon.

METHOD

In the period from November 2014 to June 2015 full thickness resections in the rectum and colon were performed with the FTRD in 20 patients. Data on technical success, R0 resection rate and histologically confirmed full thickness resections were retrospectively analyzed.

RESULTS

The following indications were treated in the rectum (n = 11) and colon (n = 9): T1 carcinoma (n = 6) and neuroendocrine tumors (n = 2), untreated and nonlifting adenomas (n = 3) and incomplete resection of adenomas with low and high grade dysplasia (n = 9). The technical success rate was 75 %, 3 technical failures made a conventional polypectomy necessary in 2 patients and in 1 patient an operative resection of the duplicated intestinal wall had to be performed. The median endoscopic follow-up time was 61.5 days (n = 10) and in 7 patients the clip had dislodged at the first follow-up. A thermal perforation in one case of conventional polypectomy gave rise to indications for a partial resection of the colon. In one patient the lesion in the cecum could be reached but not treated for technical reasons. The histological R0 rate was 80 %, whereas the full thickness resection rate was 60 % (85.7 % in the colon and 54.6 % in the rectum). In two patients with carcinoma and incomplete FTRD, surgical treatment was performed. The median size of the resection specimen was 5  cm(2) (range 1.6-12.9  cm(2)).

CONCLUSION

The results show that FTRD is a safe and effective instrument for use in the lower gastrointestinal tract. Limitations of the FTRD system concerning full thickness resection are scarring, fibrosis and thickness of the intestinal wall, especially in the lower rectum; therefore, it is suggested that a simulation with a tube similar in size to the FTRD should be performed during the screening colonoscopy in order to establish whether an endoscopic resection with FTRD is possible.

Effective dose of dental CBCT-a meta analysis of published data and additional data for nine CBCT units

OBJECTIVES

This article analyses dose measurement and effective dose estimation of dental CBCT examinations. Challenges to accurate calculation of dose are discussed and the use of dose-height product (DHP) as an alternative to dose-area product (DAP) is explored.

METHODS

The English literature on effective dose was reviewed. Data from these studies together with additional data for nine CBCT units were analysed. Descriptive statistics, ANOVA and paired analysis are used to characterize the data.

RESULTS

PubMed and EMBASE searches yielded 519 and 743 publications, respectively, which were reduced to 20 following review. Reported adult effective doses for any protocol ranged from 46 to 1073 µSv for large fields of view (FOVs), 9-560 µSv for medium FOVs and 5-652 µSv for small FOVs. Child effective doses from any protocol ranged from 13 to 769 µSv for large or medium FOVs and 7-521 µSv for small FOVs. Effective doses from standard or default exposure protocols were available for 167 adult and 52 child exposures. Mean adult effective doses grouped by FOV size were 212 µSv (large), 177 µSv (medium) and 84 µSv (small). Mean child doses were 175 µSv (combined large and medium) and 103 µSv (small). Large differences were seen between different CBCT units. Additional low-dose and high-definition protocols available for many units extend the range of doses. DHP was found to reduce average absolute error for calculation of dose by 45% in comparison with DAP.

CONCLUSIONS

Large exposure ranges make CBCT doses difficult to generalize. Use of DHP as a metric for estimating effective dose warrants further investigation.

A conceptual modeling framework for discrete event simulation using hierarchical control structures

Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM's applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models' system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example.

Radiation exposure to comforters and carers during paediatric molecular radiotherapy

BACKGROUND

To show whether the incidental radiation exposure received by comforters and carers of children undergoing molecular radiotherapy was kept as low as reasonably achievable and was within English national dose constraints.

PROCEDURE

The radiation exposure of adult comforters and carers was routinely monitored with a whole body personal dose meter while the child was in hospital. Data were collected on iodine-131 meta-iodobenzylguanidine (¹³¹ I-mIBG), lutetium-177 DOTATATE (¹⁷⁷ Lu-DOTATATE), and iodine-131 sodium iodide (¹³¹ I-NaI) treatments.

RESULTS

Data were available for 50 treatments with high-administered activity double-infusion ¹³¹ I-mIBG and 12 single administrations; 15 ¹⁷⁷ Lu-DOTATATE treatments and 28 ¹³¹ I-NaI administrations. The median age was 7 years (1-18). The median administered activity of: ¹³¹ I-mIBG was 16.2 GBq (6.8-59 GBq) for double infusion patients and 8.1 GBq (5.26-16.25 GBq) for single administrations; ¹⁷⁷ Lu-DOTATATE was 7.2 GBq (2.5-7.5 GBq); and ¹³¹ I-NaI was 3 GBq for thyroid remnant ablation and 5.5 GBq for cancer therapy. The median number of comforters and carers for all administrations was 2 (range 1-9). The median exposure values for comforters and carers for high-administered activity ¹³¹ I-mIBG administrations was 302 µSv (0-5282 µSv); for single fraction ¹³¹ I-mIBG 163 µSv (3-3104 µSv); ¹⁷⁷ Lu-DOTATATE 6 µSv (1-79 µSv); and ¹³¹ I-NaI 37 µSv (0-274 µSv). Only one of the comforters and carers exceeded the dose constraint of 5 mSv.

CONCLUSIONS

Doses to comforters and carers were in all but one case within the dose constraint nationally recommended by the Health Protection Agency, now part of Public Health England. New evidence is presented which show that comforter and carer radiation exposure levels from paediatric molecular radiotherapy in routine clinical practice are acceptably low. Pediatr Blood Cancer 2015;62:235-239. © 2014 Wiley Periodicals, Inc.