The Amazing Race Repeated Update Q-Learning VS. Q-Learning

In this paper, we will conduct an experiment that aims to compare the performance of two reinforcement learning algorithms, the Repeated Update Q-learning algorithm (RUQL) [1] and the Q-learning algorithm(QL) [5]. A simulated version of a robot crawler developed by [6] will be used in this experiment, it is shown in figure (1). An investigation study about the difference in performance between RUQL and Q-learning algorithm (QL) [5] is discussed in this paper. Several trials and tests were conducted to estimate the difference in the crawler’s movement using both algorithms. Additionally, a detailed description of the Markovian decision processes (MDPs) elements [2] is introduced, MDP model includes states, actions and rewards for the task in hand. The parameters that were used and tuned in this experiment will be mentioned and the reasons for choosing their values will be explained.  Finally, the source code for the crawler robot was modified in order to implement RUQL and Q-Learning (QL) algorithms, Eclipse [3] and Java SE Development Kit 8 (JDK) [4] are used for this purpose. After running the crawler robot simulation, the results drawn from the experiment showed that RUQL significantly outperforms the traditional QL.  &nbsp

Minimally invasive video-assisted thyroidectomy (MIVAT)

Minimally invasive video-assisted thyroidectomy (MIVAT) was first described in 1999 and it has become a widespread technique performed worldwide. Although initially limited to benign thyroid nodules, MIVAT was progressively adopted for all types of thyroid diseases, while remaining within the selection criteria. It is reported that, in selected cases, MIVAT is comparable to standard open thyroidectomy (SOT) in terms of oncologic radicality, time, costs and complications rate, with the advantage of a better cosmetic result and a lower post-operative pain

The Synergistic Impact of Combining Mutational Markers and Sonographic Features in Triaging Patients with Single Indeterminate Thyroid Nodules to Appropriate Surgery. A Prospective Study

Background. Despite the many advances in the field of nodular thyroid disease and cytopathology reporting, fine needle aspiration cytology fails to establish a reliable diagnosis in 20-30% of cases. These nodules are labeled as cytologically indeterminate for malignancy. The term indeterminate collectively applies to nodules reported as Bethesda categories III, IV, and V. Such labeling is an eyesore to health care providers as it places their patients at risk of sub-optimal therapeutic decisions. This particularly applies to Bethesda category IV whose implied risk of malignancy falls in the gray zone between those of Bethesda categories III and V. Therefore, it can neither be considered low enough for a thyroid lobectomy to become custom, nor high enough to warrant a total thyroidectomy. An additional concern is related to benignity being the most common outcome in this subset of patients. This implies that these patients are at risk of being subjected to an unnecessary and potentially morbid thyroid lobectomy. This last concern is particularly prominent in centers around the world that customarily select patients with Bethesda IV nodules for a thyroid lobectomy. At a national level, in centers around Italy, things are quite different. Most patients with Bethesda IV nodules (equivalent to TIR 3b according to the Società Italiana di Anatomia Patologica e Citopatologia Diagnostica/ International Academy of Pathology, Italian Division/ SIAPEC-IAP) are selected for a total thyroidectomy. A procedure that could be correctly labeled as “overly radical” for this subset of patients. This study aims to tackle this nation-wide issue: the near routine selection of patients with TIR 3b/ Bethesda IV nodules for a total thyroidectomy. This is best done by developing, validating and popularizing a tool that could accurately prevent unbeneficial total thyroidectomies and at the same time be readily available, easy to assemble, and cost-effective. This rule-out tool was first developed and published by the author and his colleagues in a previous retrospective study. The tool was assembled by combining negativity for suspicious gray-scale US features, and negativity for the genetic mutations commonly encountered in differentiated thyroid cancer (namely BRAF and NRAS). The gray-scale US features selected included: irregular margins, a taller-than-wide orientation, and the presence of microcalcifications, and was based on a recently published meta-analysis in the literature. The rule-out tool, abbreviated by the authors as: (US-/ Mutation-), demonstrated high predictivity for lesions that do not require a total thyroidectomy. Its predictivity of lesions for which a thyroid lobectomy is considered sufficient therapy was 94%. The current study intends on prospectively validating the efficacy of the rule-out tool in the preoperative setting in triaging patients with Bethesda IV nodules to a lobectomy instead of a total thyroidectomy. Furthermore, demonstrate the synergism between the two components used to assemble it. Methods. Between Jan. 2016 and Jan. 2018, 200 consecutive patients presented to an academic tertiary referral center with solitary thyroid nodules lacking all suspicious sonographic features set by the authors, and labeled as suspicious for a follicular neoplasm (Bethesda category IV) following FNAC. According to the authors’ published experience three grey-scale ultrasound (US) features in single or in combination are of sufficient clinical significance to label a thyroid nodule as suspicious for malignancy. These include: irregular margins, the presence of microcalcification, and a taller-than-wide configuration. The clinical significance of these US features has also been confirmed in a recent meta-analysis in the literature. Total thyroidectomy was justifiable in 33 out of the 200 patients for one the following reasons: hypothyroidism/ a background of Hashimoto’s thyroiditis (n=30), a positive family history for thyroid cancer (n=2), or a history of radiation exposure (n=1). These cases were excluded from the study, and the remaining 167 cytology smears were analyzed for NRAS and BRAF. Only 10 were positive for a mutational marker: BRAF V600E (n=1), BRAF K601E (n=1), and NRAS (n=8). Out of these mutation-positive lesions 8 were malignant, and according to the American Thyroid Association (ATA) risk stratification, six of these were high-risk and required a total thyroidectomy as a minimum surgical treatment. Ultimately 157 patients defined the authors’ study cohort and were all subjected to a thyroid lobectomy. The rule-out tool put to test in this study consisted of two components: 1. Negativity for suspicious US features and 2. Negativity for mutational markers. It was abbreviated by the authors as: (US-/ Mutation-). Its diagnostic accuracy was assessed by calculating its negative predictive value (NPV) for both malignancy and malignancy requiring a total thyroidectomy. In other words, it was evaluated for its ability to preclude total thyroidectomy as the therapeutic modality required. Whether or not mutational marker negativity imparted an additional clinical benefit (i.e. a synergistic impact) as part of this “rule-out tool” was also evaluated. This was done by calculating the NPV of US negativity but mutational positivity (US-/mutation+) for both malignancy and malignancy requiring a total thyroidectomy and comparing it to those of (US-/mutation-). Results. The 157-patient study cohort included 27 males and 130 females, with a male to female ratio of 1:5. The average age was 44 years (range: 14-75 years), and the mean nodule size was 34 mm (20-66 mm). Following lobectomy, permanent pathology revealed 140 benign lesions and 17 malignant ones. Malignancies included: the FVPTC (n=12), classical PTC (n=2), FTC (n= 2), and tall-cell PTC (n=1). Out of the 17 malignant lesions, 8 (47%) demonstrated one or more ATA high-risk features that warranted a completion thyroidectomy. From the results obtained, the NPV of (US-/mutation-) for malignancy was 89% (140/157). This increased to 95% (149/157) for malignancy requiring a total thyroidectomy. This implies a 95% diagnostic accuracy in refuting a total thyroidectomy in this subset of patients. The synergistic impact that mutational marker negativity imparted as an essential component of the tool was assessed by calculating the NPV of US negativity but mutational positivity (US-/mutation+) for both malignancy and malignancy requiring a total thyroidectomy and comparing it to those of (US-/mutation-). The NPV of (US-/mutation+) for malignancy was 20% (2/10), and 40% (4/10) for malignancy requiring total thyroidectomy. The differences were statistically significant: [NPV for malignancy: 89% vs. 20%; p < 0.0001, and NPV for malignancy requiring total thyroidectomy: 95% s. 40%; p < 0.0001]. Conclusion. The combination of (US-/mutation-) is a valid and reliable rule-out tool with sufficient pre-operative diagnostic accuracy to spare patients with Bethesda IV nodules an overly radical total thyroidectomy

Energy-based devices in thyroid surgery-an overview

In the mid-20th century Theodor Kocher standardized the conventional clamp-and-tie thyroidectomy, and a procedure that was banned or prohibited for so long was labeled as "extremely safe and efficient". Ever since, innovations and refinements in the field of thyroid surgery have focused on improving patient clinical outcome profiles, and offering patients procedures that are tailored to their concerns and desires without compromising the concepts of safety and efficacy. This led to a paradigm shift in thyroid surgery and the introduction of minimal access thyroid procedures. Unsurprisingly, this paralleled the constant technological evolution in surgical devices. Advanced energy-based devices were introduced into thyroid surgery more than a decade ago. Initially, their introduction was surrounded by sckepticism, and was considered a double-edged sword equally giving accolade and criticism. Ultimately, they have proved to be very useful in thyroid surgery, and pivotal to its evolution. In experienced hands, thyroid surgery performed using an advanced energy-based device is considered 'at least' as safe and effective as its conventional clamp-and-tie counterpart. Furthermore, it offers additional advantages that meet the best interest of the patient, surgeon, health care facility, and the society. This article provides an overview on the introduction of innovative technology into thyroid surgery

Posterior retroperitonoscopic adrenalectomy; a back door access with an unusually rapid learning curve

Posterior retroperitonoscopic adrenalectomy (PRA) has become a standard approach to the adrenal gland. The aim of this study was to report an initial experience with the procedure following a proper preparatory phase highlighting the rapidity, safety and effectiveness by which it could be introduced into a surgeon's practice. Between May 2015 and July 2016, 14 PRAs were performed in 14 patients (9 females and 5 males). The average age was 46 years, BMI: 25.5 kg/m(2), and ASA score: 2. Indications included: incidenatloma (n = 5), Conn's adenoma (n = 5), and Cushing's adenoma (n = 4). Lesions were on average 3.3 cm in size. Outcomes of interest included: operative time (OT), conversion rate, postoperative morbidity and mortality rates, and the length of hospital stay. Mean OT was 87.5 min (range 35-150 min). A significant reduction in OT occurred after the sixth procedure and was progressive thereafter. After the tenth case, the OT became less than 1 h. No conversion was required. No intra- or post-operative complications occurred, and mortality was zero. All patients commenced oral intake and ambulated following full recovery from anesthesia. The mean length of hospital stay was 3 days (range 2-6 days). PRA offers a direct access to the adrenal gland allowing for target-oriented dissection. Cognitive reorientation to the anatomy of this back door access and an adequate learning curve could be rapidly achieved by experienced and properly prepared laparoscopic surgeons. Keyword

BRAFV600E mutation: a potential predictor of more than a Sistrunk's procedure in patients with thyroglossal duct cyst carcinoma and a normal thyroid gland

To assess the utility of mutational markers in determining the most appropriate initial surgery for patients with thyroglossal duct cyst carcinoma (TGDCCa) and a normal thyroid gland. Our sample comprised 15 patients with a diagnosis of TGDCCa and a thyroid gland histologically negative for any malignant involvement, who underwent surgery between the years 1994 and 2017. Clinical records were reviewed and tissue specimens were genetically tested for the presence of the most commonly encountered mutational markers in differentiated thyroid cancer: BRAF, N-RAS, and H-RAS. The primary outcome of interest was the correlation between mutational marker positivity and the T-stage of the primary tumor and its potential implication on therapeutic decision making. All 15 cases were papillary carcinomas with a mean tumor size of 17&nbsp;mm (2-40&nbsp;mm). According to the 7th edition of the American Joint Committee on Cancer TNM staging system, these represented: T1 (n = 3), T2 (n = 1), and T3 (n = 11). Cancerous invasion of the pericystic soft tissue and/or hyoid bone was considered T3. BRAFV600E was the only mutational marker identified (7 in 15 cases). All BRAFV600E-positive lesions were T3, necessitating radioactive iodine ablation (RIA) therapy, therefore, total thyroidectomy. The correlation between BRAFV600E positivity and extracystic cancerous extension was statistically significant [1.0 (7/7) vs. 0.5 (4/8); p value = 0.0035]. BRAFV600E positivity seems to be predictive of locally advanced disease mandating RIA therapy. Therefore, it could serve as a preoperative tool that predicts the need for total thyroidectomy, in addition to Sistrunk's procedure

Underestimated risk of cancer in solitary thyroid nodules â\u89¥3Â cm reported as benign

Background: The study aims to assess the risk of cancer in solitary thyroid nodules â\u89¥30 mm in size reported as Bethesda II, and its implications. Method: The clinical records of 202 patients, who underwent thyroid lobectomy for solitary nodules measuring â\u89¥30 mm, reported as Bethesda II on preoperative FNAC between Jan 2015 and Apr 2016 were reviewed. Data collected included nodule size and consistency, and final histopathology results. The risk of cancer and the recommended management according to ATA guidelines were the outcomes of interest. Comparisons were then made between two size categories: (30â\u80\u9340 mm; n = 72; C1) and (>40 mm; n = 130; C2), and two nodule consistencies. Results: Mean nodule size was 43.2 mm (range 30â\u80\u9392). Ninety-five percent were solid and 5% were predominantly cystic. The risk of cancer was 22.8% (46/202) with no size threshold, or graded increase in risk observed. Based on biologic behavior, 50% of cancers were considered clinically significant. Accordingly, the risk of cancer for which surgery is recommended was 11.4% (23/202). The risk of cancer requiring total thyroidectomy was 9.4% and was influenced by nodule size (19 vs. 60% in C1 and C2, respectively; p = 0.01). Predominantly cystic nodules had a greater risk of malignancy compared to predominantly solid nodules even after adjusting for size (40 vs. 9.9%; p = 0.01 and 40 vs. 12.5%; p = 0.02, respectively). Conclusion: The risk of malignancy in Bethesda II solitary nodules â\u89¥30 mm is considerable implying a need for changing the way these are approached and refining cytopathology reporting

The extent of surgery in thyroglossal cyst carcinoma

Purpose: The optimal management of thyroglossal cyst carcinoma, particularly the extent of surgery required is controversial. The aim of this study was to evaluate the need for routinely adding total thyroidectomy to Sistrunk’s operation in the management of this condition. Methods: The clinical records of 19 patients with a diagnosis of thyroglossal cyst carcinoma encountered in an 11-year period (2004–2015) were reviewed. All patients underwent total thyroidectomy in addition to Sistrunk’s procedure. The rate of concomitant thyroglossal cyst and thyroid carcinomas was calculated and cancers were staged according to the AJCC-TNM staging system. Patients were divided into two groups: those with thyroglossal cyst carcinoma only (group A) and those with a synchronous or metachronous thyroid carcinoma as well (group B). The need for radioactive iodine ablation in group A was assessed. The ability to omit total thyroidectomy based on thyroglossal cancer size and a negative thyroid ultrasound was also evaluated. Results: The rate of concomitant thyroid cancer was 63.2 % (12/19). Based on stage, three out of the seven patients in group A required radioactive iodine ablation. Total thyroidectomy was ultimately justifiable in 78.9 % (15/19) of cases. Omitting total thyroidectomy in T1 thyroglossal cyst cancers or based on a sonographically normal thyroid was associated with a 43 % risk of missing thyroid malignancy. Conclusion: The routine addition of total thyroidectomy to Sistrunk’s procedure seems to be appropriate for comprehensive loco-regional control especially that selecting a subset of patients in which it could be omitted is a difficult task

Less is more: an outcome assessment of patients operated for gallstone ileus without fistula treatment

Background The treatment of gallstone ileus (GI) consists of surgical removal of the impacted bilestone with or without cholecystectomy and repair of the biliodigestive fistula. The objective of this study was to assess whether sparing patients a definitive biliary procedure adversely influenced the outcome. Materials and methods Patients with a diagnosis of GI were reviewed. Two groups were identified: patients who underwent a definitive biliary procedure with relieving the intestinal obstruction (group 1/G1) and those who did not have a definitive biliary procedure (group 2/G2). In G2, patients were evaluated on long-term follow-up for the risk of recurrent GI disease, cholecystitis, cholangitis and gallbladder cancer. Results Among 1075 patients admitted for small bowel obstruction, 20 (1.9%) were diagnosed with gallstone ileus. 3 (15%) of these belong to G1, 17 (85%) to G2. The overall postoperative morbidity rate was 35% (7/20) with one complication exceeding grade II in each group. No deaths were reported. Mean follow-up was 50 months. During follow-up, one of G2 patients had recurrent disease. No biliary tract infections or gallbladder cancer were identified. Conclusion Enterolithotomy without fistula closure is confirmed to be safe and effective for the management of gallstone ileus both on a short- and long-term basis