Strategic level proton therapy patient admission planning: a Markov decision process modeling approach

A relatively new consideration in proton therapy planning is the requirement that the mix of patients treated from different categories satisfy desired mix percentages. Deviations from these percentages and their impacts on operational capabilities are of particular interest to healthcare planners. In this study, we investigate intelligent ways of admitting patients to a proton therapy facility that maximize the total expected number of treatment sessions (fractions) delivered to patients in a planning period with stochastic patient arrivals and penalize the deviation from the patient mix restrictions. We propose a Markov Decision Process (MDP) model that provides very useful insights in determining the best patient admission policies in the case of an unexpected opening in the facility (i.e., no-shows, appointment cancellations, etc.). In order to overcome the curse of dimensionality for larger and more realistic instances, we propose an aggregate MDP model that is able to approximate optimal patient admission policies using the worded weight aggregation technique. Our models are applicable to healthcare treatment facilities throughout the United States, but are motivated by collaboration with the University of Florida Proton Therapy Institute (UFPTI).     

Effect of endogenous subclinical hyperthyroidism on bone metabolism and bone mineral density in premenopausal women.

In this cross-sectional study, we evaluated 15 premenopausal women to elucidate whether bone turnover is increased and bone mineral density is reduced due to endogenous subclinical hyperthyroidism. Each patient had normal free thyroxine (FT4) and free triiodothyronine (FT3) levels associated with a stable suppression (<0.1 mU/L) of serum thyrotropin (TSH) levels during a period ranging between 6 and 11 months. Metabolic parameters of bone turnover (serum osteocalcin, bone specific alkaline phosphatase, procollagen I C-terminal peptide reflecting bone formation; urinary deoxypyridinoline and calcium excretion reflecting bone resorption) were assessed. Bone mineral density was measured at lumbar 1-4 vertebrae, femoral neck, and the forearm (midshaft radius and distal radius) by dual energy x-ray absorptiometry. All measurements were compared with 15 healthy age-, height-, and weight-matched premenopausal women who served as control group. Our findings suggest that endogenous subclinical hyperthyroidism is not associated with increased bone turnover, and bone mineral density is not reduced in premenopausal women, at least in the short term.     

The additional diagnostic value of a single-session combined scintigraphic and ultrasonographic examination in patients with thyroid and parathyroid diseases

AIM: The aim of this study was to investigate the diagnostic efficacy and the clinical impact of scintigraphy combined with ultrasonography (USG) in the management of thyroid and parathyroid disorders in a large series of patients. METHODS: A total of 387 consecutive patients referred to the Nuclear Medicine Department of Hacettepe University in the period from January to September 2007 for investigating a thyroid (N. 339 patients: 232 females and 107 males, mean age+/-SD=48.9+/-13.6 years) or a parathyroid disease (N. 48 patients: 34 females and 14 males, mean age+/-SD=47.4+/-9.6 years) were prospectively evaluated, systematically performing both scintigraphy and USG in a single-day session. All the examinations were independently reviewed by two nuclear medicine physicians; in cases of discrepancy (3%) a final diagnosis was reached by consensus. For thyroid pathologies, USG results were considered to provide additional diagnostic information over scintigraphy: 1) if more nodules were identified; 2) if an irregular hyperactive area at scintigraphy suspicious for the presence of a nodule was clearly characterized at USG; 3) if a nodule missed at scintigraphy because of small size (<1 cm) was well depicted at USG, thus allowing an USG-guided fine needle aspiration cytology (FNAC) to reach a final diagnosis. For parathyroid pathologies, USG was considered to provide additional diagnostic information over scintigraphy if a low intensity radiotracer retention from the parathyroid suspected of being a parathyroid enlargement was clearly depicted at USG. In thyroid diseases, scintigraphy was considered to provide additional diagnostic information over USG, if the functional status of a diffuse or uni- or multi-nodular goiter were clearly defined at scintigraphy. In parathyroid diseases, scintigraphy was considered to provide additional diagnostic information over USG, if the differential diagnosis between a lymph node or a muscle or a vessel depicted at USG was clearly defined as a parathyroid enlargement at scintigraphy. Lastly, the clinical impact of the single-day combined scintigraphic/USG protocol was evaluated. RESULTS: USG. In the thyroid diseases group, USG was particularly useful: 1) to detect additional nodules in glands with suppressed thyroid tissue; 2) to disclose small thyroid nodules (<1 cm) in which it was possible to perform a USG-FNAC. In the parathyroid diseases group, USG was particularly useful for the detection of parathyroid enlargements not visualized at scintigraphy because characterized by a rapid wash-out of the radiotracer and thus by a low radioactivity intensity in the delayed scintigraphic images. Scintigraphy. In the thyroid diseases group, scintigraphy was particularly useful: 1) to diagnose a diffuse hyperfunctioning thyroid gland, and to differentiate in multinodular goiters the hyper- from the hypo-functioning nodules. In the hyperparathyroid diseases group, scintigraphy was particular useful in making a differential diagnosis between a true parathyroid enlargement vs. a lymph node or a muscle or a vessel as depicted at USG, and in cases with deeply or ectopically-positioned parathyroid glands. Combined imaging approach. Combined interpretation provided additional benefit in 225 of 339 patients (64.4%). Overall, using the combined scintigraphic/USG single-day protocol, in the thyroid diseases group the therapeutic strategy (drug therapy vs radioiodine therapy vs surgery) was changed in 176/225 patients (78.2%, P<0.001 by chi(2) of Pearson), and in the parathyroid disease group the therapeutic strategy (medical therapy vs surgery) was changed in 18/48 patients (37.5%, P<0.01 by chi2 test of Pearson). CONCLUSION: In agreement with some previous published experiences, the combined single-day scintigraphic/USG protocol systematically adopted in a large series of consecutive patients with thyroid and parathyroid diseases, enrolled in a limited period of time, proved to significantly increase the global diagnostic accuracy and to change the therapeutic strategy in more than two third of patients with a thyroid disease and in more than one third of patients with a parathyroid disease.     

Monitoring the implementation of the WHO Global Code of Practice on the International Recruitment of Health Personnel

Objective

To present the findings of the first round of monitoring of the global implementation of the WHO Global Code of Practice on the International Recruitment of Health Personnel (“the Code”), a voluntary code adopted in 2010 by all 193 Member States of the World Health Organization (WHO).

Methods

WHO requested that its Member States designate a national authority for facilitating information exchange on health personnel migration and the implementation of the Code. Each designated authority was then sent a cross-sectional survey with 15 questions on a range of topics pertaining to the 10 articles included in the Code.

Findings

A national authority was designated by 85 countries. Only 56 countries reported on the status of Code implementation. Of these, 37 had taken steps towards implementing the Code, primarily by engaging relevant stakeholders. In 90% of countries, migrant health professionals reportedly enjoy the same legal rights and responsibilities as domestically trained health personnel. In the context of the Code, cooperation in the area of health workforce development goes beyond migration-related issues. An international comparative information base on health workforce mobility is needed but can only be developed through a collaborative, multi-partnered approach.

Conclusion

Reporting on the implementation of the Code has been suboptimal in all but one WHO region. Greater collaboration among state and non-state actors is needed to raise awareness of the Code and reinforce its relevance as a potent framework for policy dialogue on ways to address the health workforce crisis.     

Ocular motility disturbances after episcleral plaque brachytherapy for uveal melanoma.

OBJECTIVE: To evaluate contributions of various factors in the development of strabismus after iodine-125 brachytherapy for uveal melanoma. METHODS: Twenty consecutive patients who underwent episcleral plaque brachytherapy for uveal melanoma underwent a full orthoptic examination before and after the surgery. Iodine-125 seeds at 5-mCi strengths were used with a mean total dose of 10.400 cGy toward the tumor apex. RESULTS: Average follow-up time was 25.4 months (range, 14 to 40). At 12 months all tumors showed regression, 9 patients had visual acuity of 20/200 or better, and 4 patients had ambulatory vision. After tumor treatment, 8 patients were orthophoric, 9 patients developed exotropia, 1 patient became hypertropic, 2 patients developed exotropia and hypertropia. Of 2 patients who developed significant diplopia, 1 received 10 U botulinum-toxin A injection (Botox, Allergan, Irvine, CA) for exotropia, and the other was managed with superior rectus advancement and superior oblique tenectomy for surgery-induced iatrogenic Brown's syndrome and slipped superior rectus muscle. CONCLUSION: Extensive mechanical injury, possible ionizing radiation of the plaques, and low visual acuity may cause strabismus after episcleral plaque brachytherapy. Diplopia and cosmesis could be improved with Botox injection or strabismus surgery.     

Serum Prolidase and IGF-1 as Non-invasive Markers of Hepatic Fibrosis During Four Different Periods After Bile-duct Ligation in Rats

AIM: Our aim was to study the correlation of serum prolidase and insulin like growth factor-1 to liver collagen and assess their utility as markers of fibrosis during four different periods of hepatic injury and fibrosis after bile-duct ligation in rats. METHODS: Forty-eight Wistar albino rats were included in the study and divided into six groups. Seven rats served as the control group (Control), while seven rats had a sham operation (Sham group). Thirty-four rats underwent bile-duct ligation. Bile-duct ligated (BDL) animals were sacrificed at the end of the first week (Group 1; n = 8), second week (Group 2; n = 8), third week (Group 3; n = 9), or fourth week (Group 4; n = 9) after BDL. Liver collagen, liver prolidase, and serum prolidase and IGF-I, were determined. RESULTS: There was a positive correlation between liver collagen and serum prolidase (r(s): 0.843, P < 0.001) levels and a negative correlation among liver collagen and serum IGF-1 levels (r(s): -0.667, P < 0.001). The peak levels of liver collagen and serum prolidase were reached in the third week while the lowest levels of IGF-1 were found at the end of the third week. CONCLUSION: Serum prolidase and IGF-1 either independently or in combination correlate with liver collagen content in hepatic fibrosis.