Management of androgen-ablation refractory prostate cancer. Role for somatostatin analogues?

Patients with metastasised prostate cancer survive longer with anti-androgen therapy but eventually all progress into the androgen-ablation refractory (AAR) stage and die. There are only few effective strategies to treat patients with AAR cancers and they include even more effective androgen blockade by for example glucocorticoids or ketoconazole. Some of the tumours differentiate into neuroendocrine tumours and become completely independent of androgen stimulation. It is believed that these tumours over-express somatostatin receptors which may be a new target for the anti-tumour treatment. In this article we present a patient with advanced AAR prostate cancer and intractable retching and vomiting. As the last resort, he was treated with octreotide SC which resulted rapid amelioration of the symptoms and in significantly decreased PSA which could be translated into longer survival. In this article we review rationale for the use of somatostatin analogues in the treatment of patients with hormone-refractory prostate cancer. Adv. Pall. Med. 2010; 9, 4: 145–150Patients with metastasised prostate cancer survive longer with anti-androgen therapy but eventually all progress into the androgen-ablation refractory (AAR) stage and die. There are only few effective strategies to treat patients with AAR cancers and they include even more effective androgen blockade by for example glucocorticoids or ketoconazole. Some of the tumours differentiate into neuroendocrine tumours and become completely independent of androgen stimulation. It is believed that these tumours over-express somatostatin receptors which may be a new target for the anti-tumour treatment. In this article we present a patient with advanced AAR prostate cancer and intractable retching and vomiting. As the last resort, he was treated with octreotide SC which resulted rapid amelioration of the symptoms and in significantly decreased PSA which could be translated into longer survival. In this article we review rationale for the use of somatostatin analogues in the treatment of patients with hormone-refractory prostate cancer. Adv. Pall. Med. 2010; 9, 4: 145–15

A new paradigm for minimax search

This paper introduces a new paradigm for minimax game-tree search algorithms. MT is a memory-enhanced version of Pearl's Test procedure. By changing the way MT is called, a number of best-first game-tree search algorithms can be simply and elegantly constructed (including SSS*). Most of the assessments of minimax search algorithms have been based on simulations. However, these simulations generally do not address two of the key ingredients of high performance game-playing programs: iterative deepening and memory usage. This paper presents experimental data from three game-playing programs (checkers, Othello and chess), covering the range from low to high branching factor. The improved move ordering due to iterative deepening and memory usage results in significantly different results from those portrayed in the literature. Whereas some simulations show alpha-beta expanding almost 100% more leaf nodes than other algorithms [Marsland, Reinefeld & Schaeffer, 1987], our results showed variations of less than 20%. One new instance of our framework MTD(f) out-performs our best alpha-beta searcher (aspiration NegaScout) on leaf nodes, total nodes and execution time. To our knowledge, these are the first reported results that compare both depth-first and best-first algorithms given the same amount of memory

Improving multivariate Horner schemes with Monte Carlo tree search

Optimizing the cost of evaluating a polynomial is a classic problem in computer science. For polynomials in one variable, Horner's method provides a scheme for producing a computationally efficient form. For multivariate polynomials it is possible to generalize Horner's method, but this leaves freedom in the order of the variables. Traditionally, greedy schemes like most-occurring variable first are used. This simple textbook algorithm has given remarkably efficient results. Finding better algorithms has proved difficult. In trying to improve upon the greedy scheme we have implemented Monte Carlo tree search, a recent search method from the field of artificial intelligence. This results in better Horner schemes and reduces the cost of evaluating polynomials, sometimes by factors up to two.Comment: 5 page

Onset of hypothyroidism after total laryngectomy:Effects of thyroid gland surgery and preoperative and postoperative radiotherapy

Background: To determine time of onset and risk of hypothyroidism after total laryngectomy (TL) with and without (hemi)thyroidectomy in relation to treatment regimen, that is, preoperative radiotherapy (RT-TL), postoperative radiotherapy (TL-RT), and postoperative re-irradiation (RT-TL-RT). Methods: Retrospective review of 128 patients treated by RT-TL (51 patients), TL-RT (55 patients), and RT-TL-RT (22 patients). Risk of hypothyroidism was determined by multivariable Cox regression analysis and euthyroid survival was calculated using Kaplan-Meier method. Results: Hypothyroidism developed in 69 (54%) patients. The median onset of hypothyroidism was later (P <.01) and the risk of hypothyroidism was lower (hazard ratio 0.49; P =.014) in the TL-RT group compared to both other treatment regimens. Euthyroid survival did not differ between the treatment regimens. Two years euthyroid survival was 24% with and 61% without (hemi)thyroidectomy (P <.001). Conclusions: Patients treated with TL-RT have later onset of hypothyroidism. Higher risk for hypothyroidism is associated with salvage TL after radiotherapy and (hemi)thyroidectomy

An Automated Scalable Framework for Distributing Radio Astronomy Processing Across Clusters and Clouds

The Low Frequency Array (LOFAR) radio telescope is an international aperture synthesis radio telescope used to study the Universe at low frequencies. One of the goals of the LOFAR telescope is to conduct deep wide-field surveys. Here we will discuss a framework for the processing of the LOFAR Two Meter Sky Survey (LoTSS). This survey will produce close to 50 PB of data within five years. These data rates require processing at locations with high-speed access to the archived data. To complete the LoTSS project, the processing software needs to be made portable and moved to clusters with a high bandwidth connection to the data archive. This work presents a framework that makes the LOFAR software portable, and is used to scale out LOFAR data reduction. Previous work was successful in pre-processing LOFAR data on a cluster of isolated nodes. This framework builds upon it and and is currently operational. It is designed to be portable, scalable, automated and general. This paper describes its design and high level operation and the initial results processing LoTSS data