Feasibility of Multisolutions Optimization Technique for Real-Time HDR Brachytherapy of Prostate

The purpose of this study was to evaluate the efficacy of multisolutions optimization algorithm for High Dose Rate (HDR) brachytherapy of prostate. In this retrospective study, we included data from 20 prostate cancer patients who underwent ultrasound based real time HDR Brachytherapy at institution. The treatment plans of all 20 patients were optimized in Oncentra Prostate treatment planning system (TPS) using inverse dose volume histogram based optimization followed by graphical optimization (GRO) in real time. The data of all the patients were retrieved later, and the treatment plans were re-optimized using multisolutions dose volume histogram based optimization (MDVHO) and multisolutions variance based optimization (MVBO) algorithms with same set of dose constraints, same number of catheters, and same contour set as in GRO. Several Pareto optimal solutions were obtained by varying the weighting factors of composite objective function in finite steps of adequate resolutions.  These solutions were then stored in the database of TPS and same decision criteria was employed to pick the final solution using a decision engine. The average values for planning target volume receiving 100% of prescribed dose (V100) for MDVHO, MVBO, and GRO were 95.03%, 86.72% and 97.56%, respectively. The average V100 due to MDVHO was statistically significant (P = 0.002) in comparison to MVBO, whereas the average V100 due to MDVHO and GRO was not statistically significant (P = 0.066). In conclusion, the MDVHO can provide comparable solutions to typical clinical optimizations using GRO within clinically reasonable amount of time. In most of the cases, the plans created by MVBO were not clinically acceptable without users’ further manual intervention

Dosimetric impact of mixed-energy volumetric modulated arc therapy plans for high-risk prostate cancer

oai:ojs.ijcto.org:article/6Purpose: This study investigated the dosimetric impact of mixing low and high energy treatment plans for prostate cancer treated with volumetric modulated arc therapy (VMAT) technique in the form of RapidArc.Methods: A cohort of 12 prostate cases involving proximal seminal vesicles and lymph nodes was selected for this retrospective study. For each prostate case, the single-energy plans (SEPs) and mixed-energy plans (MEPs) were generated.  First, the SEPs were created using 6 mega-voltage (MV) energy for both the primary and boost plans. Second, the MEPs were created using 16 MV energy for the primary plan and 6 MV energy for the boost plan. The primary and boost MEPs used identical beam parameters and same dose optimization values as in the primary and boost SEPs for the corresponding case. The dosimetric parameters from the composite plans (SEPs and MEPs) were evaluated. Results: The dose to the target volume was slightly higher (on average <1%) in the SEPs than in the MEPs. The conformity index (CI) and homogeneity index (HI) values between the SEPs and MEPs were comparable. The dose to rectum and bladder was always higher in the SEPs (average difference up to 3.7% for the rectum and up to 8.4% for the bladder) than in the MEPs. The mean dose to femoral heads was higher by about 0.8% (on average) in the MEPs than in the SEPs. The number of monitor units and integral dose were higher in the SEPs compared to the MEPs by average differences of 9.1% and 5.5%, respectively.Conclusion: The preliminary results from this study suggest that use of mixed-energy VMAT plan for high-risk prostate cancer could potentially reduce the integral dose and minimize the dose to rectum and bladder, but for the higher femoral head dose.-----------------------------------------------Cite this article as:Pokharel S. Dosimetric impact of mixed-energy volumetric modulated arc therapy plans for high-risk prostate cancer. Int J Cancer Ther Oncol 2013;1(1):01011.DOI: http://dx.doi.org/10.14319/ijcto.0101.1  //

Dose-to-medium vs. dose-to-water: Dosimetric evaluation of dose reporting modes in Acuros XB for prostate, lung and breast cancer

Purpose: Acuros XB (AXB) dose calculation algorithm is available for external beam photon dose calculations in Eclipse treatment planning system (TPS). The AXB can report the absorbed dose in two modes: dose-to-water (Dw) and dose-to-medium (Dm). The main purpose of this study was to compare the dosimetric results of the AXB_Dm with that of AXB_Dw on real patient treatment plans. Methods: Four groups of patients (prostate cancer, stereotactic body radiation therapy (SBRT) lung cancer, left breast cancer, and right breast cancer) were selected for this study, and each group consisted of 5 cases. The treatment plans of all cases were generated in the Eclipse TPS. For each case, treatment plans were computed using AXB_Dw and AXB_Dm for identical beam arrangements. Dosimetric evaluation was done by comparing various dosimetric parameters in the AXB_Dw plans with that of AXB_Dm plans for the corresponding patient case. Results: For the prostate cancer, the mean planning target volume (PTV) dose in the AXB_Dw plans was higher by up to 1.0%, but the mean PTV dose was within ±0.3% for the SBRT lung cancer. The analysis of organs at risk (OAR) results in the prostate cancer showed that AXB_Dw plans consistently produced higher values for the bladder and femoral heads but not for the rectum. In the case of SBRT lung cancer, a clear trend was seen for the heart mean dose and spinal cord maximum dose, with AXB_Dw plans producing higher values than the AXB_Dm plans. However, the difference in the lung doses between the AXB_Dm and AXB_Dw plans did not always produce a clear trend, with difference ranged from -1.4% to 2.9%. For both the left and right breast cancer, the AXB_Dm plans produced higher maximum dose to the PTV for all cases. The evaluation of the maximum dose to the skin showed higher values in the AXB_Dm plans for all 5 left breast cancer cases, whereas only 2 cases had higher maximum dose to the skin in the AXB_Dm plans for the right breast cancer. Conclusion: The preliminary dosimetric results from our clinical study showed that the selection of either Dm or Dw in AXB is less likely to produce significant dosimetric differences in the clinical environment. However, the difference between the AXB_Dm and AXB_Dw calculations depends on the disease site, and even for the same type of disease (e.g., lung cancer), the results are patient specific

The potential of health literacy to address the health related UN sustainable development goal 3 (SDG3) in Nepal: a rapid review

BackgroundHealth literacy has been linked to health outcomes across population groups around the world. Nepal, a low income country, experiences the double burden of highly prevalent communicable as well as non-communicable diseases. The World Health Organization (WHO) has positioned health literacy as a key mechanism to meet the health-related Sustainable Development Goal (SDG3). However, there is little known about the status of health literacy in developing countries such as Nepal. This paper aims to review the potential of health literacy to address SDG3 in Nepal.MethodsA rapid review was conducted using the knowledge to action evidence summary approach. Articles included in the review were those reporting on barriers to health care engagements in Nepal published in English language between January 2000 and December 2015.ResultsBarriers for healthcare engagement included knowledge and education as strong factors, followed by culture, gender roles, quality of service and cost of services. These barriers influence the Nepalese community to access and engage with services, and make and enact healthcare decisions, not only at the individual level but at the family level. These factors are directly linked to health literacy. Health literacy is a pivotal determinant of understanding, accessing and using health information and health services, it is important that the health literacy needs of the people be addressed.ConclusionLocally identified and developed health literacy interventions may provide opportunities for systematic improvements in health to address impediments to healthcare in Nepal. Further research on health literacy and implementation of health literacy interventions may help reduce inequalities and increase the responsiveness of health systems which could potentially facilitate Nepal to meet the sustainable development goals. While there is currently little in place for health literacy to impact on the SDG3, this paper generates insights into health literacy&rsquo;s potential role.<br /

Reusable sanitary towels: promoting menstrual hygiene in post-earthquake Nepal.

It is a normal human tendency to 'run for your life' when an earthquake occurs. Adolescent girls and women of reproductive age leave their homes with only the clothes they are wearing to save their own and their families' lives. Immediate disaster relief aid with its (unintentional) lack of gender sensitivity has little or no materials for the appropriate management of menstrual hygiene. The biological needs of disaster-affected women will not change despite the dire need for basic food, shelter and security. Timely identification and preparation beforehand with appropriate and culturally sensitive techniques and locally available materials that are reusable can help introduce sustainable and acceptable means of managing menstrual hygiene in a crisis. The use of reusable sanitary towels is well accepted for menstrual hygiene management in non-disaster situations and is appropriate in post-earthquake relief in Nepal

The COVID‐19 Pandemic Not Only Poses Challenges, but Also Opens Opportunities for Sustainable Transformation

The COVID-19 pandemic has impacted social, economic, and environmental systems worldwide, slowing down and reversing the progress made in achieving the Sustainable Development Goals (SDGs). SDGs belong to the 2030 Agenda to transform our world by tackling humankind's challenges to ensure well-being, economic prosperity, and environmental protection. We explore the potential impacts of the pandemic on SDGs for Nepal. We followed a knowledge co-creation process with experts from various professional backgrounds, involving five steps: online survey, online workshop, assessment of expert's opinions, review and validation, and revision and synthesis. The pandemic has negatively impacted most SDGs in the short term. Particularly, the targets of SDG 1, 4, 5, 8, 9, 10, 11, and 13 have and will continue to have weakly to moderately restricting impacts. However, a few targets of SDG 2, 3, 6, and 11 could also have weakly promoting impacts. The negative impacts have resulted from impeding factors linked to the pandemic. Many of the negative impacts may subside in the medium and long terms. The key five impeding factors are lockdowns, underemployment and unemployment, closure of institutions and facilities, diluted focus and funds for non-COVID-19-related issues, and anticipated reduction in support from development partners. The pandemic has also opened a window of opportunity for sustainable transformation, which is short-lived and narrow. These opportunities are lessons learned for planning and action, socio-economic recovery plan, use of information and communication technologies and the digital economy, reverse migration and “brain gain,” and local governments' exercising authorities

Dosimetric impact of mixed-energy volumetric modulated arc therapy plans for high-risk prostate cancer

<p><strong>Purpose: </strong>This study investigated the dosimetric impact of mixing low and high energy treatment plans for prostate cancer treated with volumetric modulated arc therapy (VMAT) technique in the form of RapidArc.</p><p><strong>Methods: </strong>A cohort of 12 prostate cases involving proximal seminal vesicles and lymph nodes was selected for this retrospective study. For each prostate case, the single-energy plans (SEPs) and mixed-energy plans (MEPs) were generated.  First, the SEPs were created using 6 mega-voltage (MV) energy for both the primary and boost plans. Second, the MEPs were created using 16 MV energy for the primary plan and 6 MV energy for the boost plan. The primary and boost MEPs used identical beam parameters and same dose optimization values as in the primary and boost SEPs for the corresponding case. The dosimetric parameters from the composite plans (SEPs and MEPs) were evaluated. <strong></strong></p><p><strong>Results: </strong>The dose to the target volume was slightly higher (on average &lt;1%) in the SEPs than in the MEPs. The conformity index (CI) and homogeneity index (HI) values between the SEPs and MEPs were comparable. The dose to rectum and bladder was always higher in the SEPs (average difference up to 3.7% for the rectum and up to 8.4% for the bladder) than in the MEPs. The mean dose to femoral heads was higher by about 0.8% (on average) in the MEPs than in the SEPs. The number of monitor units and integral dose were higher in the SEPs compared to the MEPs by average differences of 9.1% and 5.5%, respectively.</p><p><strong>Conclusion: </strong>The preliminary results from this study suggest that use of mixed-energy VMAT plan for high-risk prostate cancer could potentially reduce the integral dose and minimize the dose to rectum and bladder, but for the higher femoral head dose.</p><p>-----------------------------------------------</p><p><strong>Cite this article as:</strong><br />Pokharel S. Dosimetric impact of mixed-energy volumetric modulated arc therapy plans for high-risk prostate cancer. <em>Int J Cancer Ther Oncol</em> 2013;<strong>1</strong>(1):01011.<br /><br /></p><p><strong>DOI</strong>: <a href="http://dx.doi.org/10.14319/ijcto.0101.1" target="_blank">http://dx.doi.org/10.14319/ijcto.0101.1</a></p><p> </p><div id="fb-root"> </div><script type="text/javascript">// <![CDATA[ (function(d, s, id) { var js, fjs = d.getElementsByTagName(s)[0]; if (d.getElementById(id)) return; js = d.createElement(s); js.id = id; js.src = "//connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.0"; fjs.parentNode.insertBefore(js, fjs); }(document, 'script', 'facebook-jssdk')); // ]]></script><div class="fb-like" data-href="http://ijcto.org/index.php/IJCTO/article/view/Pokharel" data-width="500" data-layout="standard" data-action="recommend" data-show-faces="false" data-share="true"> </div

Dosimetric impact of mixed-energy volumetric modulated arc therapy plans for high-risk prostate cancer

Purpose: This study investigated the dosimetric impact of mixing low and high energy treatment plans for prostate cancer treated with volumetric modulated arc therapy (VMAT) technique in the form of RapidArc.Methods: A cohort of 12 prostate cases involving proximal seminal vesicles and lymph nodes was selected for this retrospective study. For each prostate case, the single-energy plans (SEPs) and mixed-energy plans (MEPs) were generated.  First, the SEPs were created using 6 mega-voltage (MV) energy for both the primary and boost plans. Second, the MEPs were created using 16 MV energy for the primary plan and 6 MV energy for the boost plan. The primary and boost MEPs used identical beam parameters and same dose optimization values as in the primary and boost SEPs for the corresponding case. The dosimetric parameters from the composite plans (SEPs and MEPs) were evaluated. Results: The dose to the target volume was slightly higher (on average &lt;1%) in the SEPs than in the MEPs. The conformity index (CI) and homogeneity index (HI) values between the SEPs and MEPs were comparable. The dose to rectum and bladder was always higher in the SEPs (average difference up to 3.7% for the rectum and up to 8.4% for the bladder) than in the MEPs. The mean dose to femoral heads was higher by about 0.8% (on average) in the MEPs than in the SEPs. The number of monitor units and integral dose were higher in the SEPs compared to the MEPs by average differences of 9.1% and 5.5%, respectively.Conclusion: The preliminary results from this study suggest that use of mixed-energy VMAT plan for high-risk prostate cancer could potentially reduce the integral dose and minimize the dose to rectum and bladder, but for the higher femoral head dose.-----------------------------------------------Cite this article as:Pokharel S. Dosimetric impact of mixed-energy volumetric modulated arc therapy plans for high-risk prostate cancer. Int J Cancer Ther Oncol 2013;1(1):01011.DOI: http://dx.doi.org/10.14319/ijcto.0101.1  // <![CDATA[ (function(d, s, id) { var js, fjs = d.getElementsByTagName(s)[0]; if (d.getElementById(id)) return; js = d.createElement(s); js.id = id; js.src = "//connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.0"; fjs.parentNode.insertBefore(js, fjs); }(document, 'script', 'facebook-jssdk')); // ]]> </div