Gated DIBH for Left Sided Breast Cancer Patients

Gated DIBH for Left Sided Breast Cancer tolerantsChapter III Methodology3.1 investigate ObjectivesThe query project examines leftfield-sided breast crabby person unhurrieds receiving therapy with gated DIBH technique use the commercially avail equal revolutions per minute system. The primary objective of this interrogation is to evaluate whether left-sided breast preemptcer patients will benefit from gated DIBH. The interest in per social classing this research arises from having many left-sided breast genus Cancer patients that constitute large volume of heart in the treatment field, and hence are at risk for cardiac toxicities in the prox. The secondary objectives of this research is to look at patients comfort and understanding, and shaft healers workload. This chapter will discuss the exemplification selection, ethical issues, instrumentation, information collection procedures, data analysis, limitations, expected results, budget and prison termline.3.2 Sample selection and descriptionThe expected take in size was careful utilise the formula (Chan, 2003) for paired samples as seen below,Total sample size = where c is 10.5 for 90% power, is the standardised effect size, given by the formula (Chan, 2003)where 1 and 2 are the means of the two treatment groups, and is the common standard deviation.The 90% power represents the probability of rejecting the null hypothesis when it is bogus (Chan, 2003). It is postulated that a good treatment contrariety () between the 2 groups is 0.2 units with an SD () of 0.5 units (Chan, 2003). With these values, the expected sample size is 68.Sixty-eight left-sided breast scum bagcer patients will be selected for this research utilise a simple random sampling method. The patient population will be chosen at random to create a divers(prenominal) group of patients with variable breast and heart volumes.The criteria for this sample would be female patients with left-sided breast cancer below the age of 7 0. In addition, the patients must be able to generate their breath. These patients will be recruited after being screened by the oncologists. The oncologists will do a simple breath-hold test with patients to make up if they are able to hold their breath for at least 20 seconds. This is because patients will be postulate to hold their breath during the CT scan for a duration of 18 seconds.This research will require 2 sets of computed-tomography (CT) scans from each patient of which one is at free breathing and the other at DIBH. Both sets will have undistinguishable patient setup. Patients will be lying supine with both arms above head on a posirest, having the visual goggles on (see auxiliary M, image A) with a 6-reflective markers block on patients anterior abdominal surface (see Appendix H). With the goggles, they are able to view the screen, as seen in image B in Appendix M, in order to see their breathing patterns. For each patient, 2 treatment excogitations will be gener ated one utilise the CT images at free breathing with photon electron suffer technique and the other using the CT images at DIBH with gated DIBH technique using RPM with 3-mm intervals.3.3 honest Issues and Informed consentAny research involving human subjects conducted in the hospital would require adherence to ethical standards. The procedure requires the collation of a list of investigators in the department that intends to conduct clinical trials (see Appendix N), and to apply and attend the Singapore Guideline for Good Clinical Practice (SGGCP) course. This Course ensures that the conduct of clinical trials follows internationally acceptable ethical and scientific standards (see Appendix O). The ethics review will be carried out by the National Healthcare Group domain specialized review board which is an independent committee constituted of medical, scientific and non-scientific members, whose responsibility is to ensure the protection of the rights, safety and head-being of human subjects involved in a research study by reviewing, approving and providing continuing review of research studies, and of the methods and materials to be used in obtaining and documenting sensible consent of the research subjects (National University Health System, 2010). When a principal investigator submits an application via the research online administration and management system, it is automatically routed to the department representative for endorsement, and subsequently the institution representative for endorsement, before it is delivered to the domain particular(prenominal) review board secretariat (National University Health System, 2010). All research studies submitted will be classified under one of the following review categories exempt review, expedited review, salutary Board review (see Appendix P) (National University Health System, 2010). Based on the definitions in Appendix P, this study is classified as an expedited review.Ethics approval for research is required for several reasons. Firstly, ethical norms promote the aims of research, much(prenominal) as knowledge, truth, and avoidance of error (Resnik, 2011).Secondly, ethical standards promote the values that are essential to collaborative work, such as trust, accountability, mutual respect, and fairness (Resnik, 2011). For example, guidelines for authorship, copyright and patenting policies, data sharing policies, and confidentiality rules in peer review, are designed to protect intellectual property interests while encouraging quislingism (Poortmans, 2013).Ethical norms in research also help to build public support for research as people are to a greater extent likely to shop research project if they can trust the quality and integrity of research (Resnik, 2011).Finally, many of the norms of research promote a variety of other important honorable and social values, such as social responsibility, human rights, compliance with the law, and health and safety. This also prot ect the rights and welfare of participants and minimise the risk of physical and mental vexation and harm from research procedures (Canterbury Christ Church University, 2006). Ethical lapses in research can strongly harm human subjects especially if the researcher fails to abide by the regulations and guidelines relating to radiation or biological safety (Resnik, 2011).Informed consent is the process by which the patient voluntarily confirms her willingness to participate in this research, after being informed of all the aspects of the research that are relevant to her decision-making (National Healthcare Group, 2013). The informed consent is documented by means of written signatures, date informed consent form and the language used during the explanation to the patient by the oncologist. In the consent, in that respect should be 3 signatures the patients, the doctors and the witness signature. For patients who cannot read and emit English, a qualified translator will be around during the signing of the consent.3.4 Research design and instrumentationThis research is a mixture of qualitative and numerical research methods (see Appendix Q). Quantitative research corresponds to a deductive scientific method of research which uses data in the form of numbers and statistics to test hypotheses, using a large and randomly selected sample that is a representative of the population (Pearce, et al. 2013 Johnson Christensen 2010).This is in contrast to the qualitative approach which corresponds to an inductive method of research which uses words, pictures or objects to examine a phenomenon, requiring only a small and non-randomly selected sample (Pearce, et al. 2013 Johnson Christensen 2010).Patients will be scanned using Toshiba Aquilion Large Bore CT-simulator (Toshiba, 2014). The treatment plans will be generated using Varian Medical Eclipse Treatment Planning System and patients will be tempered with DIBH technique using RPM from Varian Trilogy elongate accel erator (Varian Medical System, 1999-2014).3.5 data collection proceduresThe comparable radiation oncologist will perform all the delineation of the clinical target volume, the heart and LADCA for consistency purposes (see Appendix R). The delineation will be done according to radiation therapy oncology group (RTOG) breast contouring recommendations (Goksel, et al., 2013). Patients CT images at breath hold will be used to plan for DIBH technique while the one at free breathing will be planned for photon electron match technique. The treatments will be planned such that the clinical target volumes coverage of the dit distribution is kept between 90% and 110% of the prescribed dose. For each plan, heart and LADCA volumes were calculate in cm3. Dose volumes to the heart and LADCA will be normalized by dividing with the total organ volume. Heart and LADCA volumes receiving 5Gy to 50Gy (V5-V50) will be generated for comparison of treatment techniques. Dose distributions can be present ed as DVHs and representing the statistical dose distribution in a volume of interest. These statistical data will be record and presented in tables.Patient education is a very important component in DIBH technique using RPM to reduce anxiety and increase their confidence about receiving radiation therapy (Halkett Kristjanson, 2007). Patient education tools can be in many forms such as video or pamphlet (Halkett Kristjanson, 2007). For this research, a pamphlet have been created to improve patients on DIBH technique using RPM (see Appendix S). A qualitative research method such as face-to-face question is chosen to survey patients comfort and understanding at the middle of the treatment and on the last mean solar day of treatment as this only require the patients to discourse the same language in which the questions are asked, and to have basic verbal and listening skills (Bowling, 2009). The primary objective of this standardised and open-ended interview (Valenzuela Shrivas tava, n.d.) is to determine the head of understanding as well as patients comfort. The questions (see Appendix T) will be asked by the oncologist during the middle of the treatment and on the last day of treatment.The advantages of face-to-face interviews are that reading and writing skills are not required, interviewers are able to probe fully for responses and clarify any ambiguities, they can ask more complicated and detailed questions, and patients are able to clarify if they do not understand the questions (Bowling, 2009). This would be a better technique than self-administered questionnaires because pre-coded response choices may not be sufficiently comprehensive and patients may be forced to choose inappropriate pre-coded answers that might not fully represent their views (Bowling, 2009). This causes the data to be diverge as the patients replies are influenced by the design of the pre-coded response choices. Self-administered questionnaires also assumed that the questions are worded in a way that is understood by the patients (Bowling, 2009). Patients may misinterpret the questions and reply based on their own interpretation and questionnaires may be a problem for patients who are unable to read or write (Bowling, 2009). Most importantly, one-to-one interviews with standardised questions appeared to have the highest reliability (University of Leicester, n.d.).The radiation therapists workload will be thrifty in terms of training hours, and the comparison of treatment duration and manpower required for gated DIBH using RPM and photon electron match technique (see Appendix U) will be recorded and presented in charts.3.6 Data analysisPaired samples t-test will be used to determine whether there is a significant difference between the average dose to the heart and LADCA values made under photon electron match plan and gated DIBH using RPM plan (Norman Streiner, 2008). This is used because the data are measured at the scale level and the data are relat ed (Hawkins, 2009). The amount of radiation authentic by the heart can be recorded by comparability the DVHs of the photon electron match with gated DIBH using RPM. The statistical figures can be analysed using Statistical Package for Social Sciences (SPSS) (Yavas, et al., 2012). Paired samples t-test will be used to determine whether there is a significant difference between the average dose to the heart and LADCA values made under photon electron match plan and gated DIBH using RPM plan (Easton McColl, 2014). A p-value of Patients understanding and comfortThe questions (see Appendix T) from the standardised and open-ended interview were developed by a group of 2 radiation oncologists, a nurse and 2 radiation therapists. The areas of discussion were based on the groups clinical experience with left-sided breast cancer patients and their extensive knowledge on DIBH using RPM. The interview aims to determine the patients level of comfort and understanding of the gated DIBH using R PM. The design of the questionnaire will determine the reliability and validity of the opened-ended interview to measure patients level of comfort and understanding.Reliability is defined as the extent to which questionnaire will produce the same results on repeated trials (Miller, n.d.), and is measured by its equivalence and stability. Equivalence reliability assesses the consistency of the judgement of the patients answer by the interview (Miller, n.d.). It is improve by pre-empting a range of responses that might be given by the patients and give a pre-determined rating to each response so that the interviewers will have the same level of judgement (Miller, n.d.). For example, _____________-Stability reliability is correlated to the repeatability of the patients response under the same conditions after a period of time (Miller, n.d.). For this interview, the patients will be interviewed twice, once during mid-treatment and the other on the last day of their treatment. Their res ponses from both sessions will be compared to determine if there are any deviance. This assumes that the characteristics that is measured doesnt change with time, and that the time period is long enough that the memories from the 1st interview will not influence the responses of the 2nd interview (Miller, n.d.).The validity of the interview is the extent to which the interview questions measures what it purport to measure, and it generally takes the form of content validity (Miller, n.d.). Content validity is the degree to which the questions fully assess or measure the excogitation of the interview (Miller, n.d.). This was determined by letting the team review the individual questions for readability, clarity and comprehensiveness and come to some level of agreement as to which items should be included in the final interview questions. The interview questions (see Appendix T) were reviewed and accepted by the team prior to the conduct of the interview.The treatment duration will b e recorded as seen in Appendix U and a paired samples t-test similar to appendix V will be used to determine whether there is a significant difference, where the null hypothesis (H0) is there is no difference between the treatment time with photon electron match technique and DIBH using RPM technique.The radiation therapist workload will be analysed based on the minimum number of manpower required for gated DIBH using RPM as compared to photon electron match technique and in terms of training hours. This will be discussed among the radiation therapists and presented in charts.3.7 LimitationThis research can only sample from a small size due to constraint of resources where there is only 1 treatment unit that has the RPM equipment required for DIBH technique. The expected sample size calculated is only an estimate as the treatment difference and standard deviation are never known in advance (Norman Streiner, 2008). As such, the actual sample size may be slightly smaller than 68.3.8 Expected ResultsThe results from this research are expected to show optimal radiation exposure volumes and doses for the heart and LADCA when treated with gated DIBH using RPM compared to photon electron match technique at free breathing. These results are expected to be compatible with findings from previous studies (Pedersen, et al., 2004 Korreman, et al., 2005 Shim, et al., 2012 Mast, et al., 2013). As such, showing that patients with left sided breast cancer will benefit from gated DIBH using RPM. Treatment time duration for gated DIBH using RPM is expected to have a significant difference and be faster than photon electron match technique. As gated DIBH using RPM is new to the radiation therapists, the workload is expected to be heavier in the beginning.3.9 Budget on that point will be no additional cost for this research as the RPM equipment is already available together with the linear accelerator from Varian (Varian Medical System, 1999-2014). in that location will be no co st for training on the usage for RPM by Varian as it was included in the package when the linear accelerators were bought in 2013. Patients recruited for this research will be charged the same cost as photon electron match treatment technique.3.10 Expected TimelineThis research aims to commence from January 2015 till declination 2015. The work plan for both the principal investigator and research assistants can be seen in Appendix W.Chapter IV ConclusionThis research aims to review gated DIBH using RPM as a treatment technique for left-sided breast cancer patients as compared to photon electron match in terms of the radiation dose received by the heart and LADCA. Paired t-test is chosen to measure the significant difference between the dose received by the heart in photon electron match technique and DIBH using RPM technique. Based on literatures that were review, the results are expected to be in favour of gated DIBH using RPM. Interviews will be conducted to assess patients comfo rt and understanding about gated DIBH using RPM. And data collection will be done gauge the workload of the radiation therapist. The results from interview and data collection will allow us to gauge further if it is really practical to implement gated DIBH using RPM in our department. If the results are clinically significant and positive, gated DIBH using RPM will be implemented into our department.4.1 RecommendationFor future recommendation to try contrast-enhanced CT scan in left-sided breast patients so that the LADCA can be seen clearly in the scan and able to be delineated by the doctor effectively (Yu, et al., 2013). This is to increase the accuracy of the delineation of LADCA as well as the accurate amount of radiation dose received by it. After this research, another study can be done in the future on the reproducibility of patients breath holding level for every fraction using a cine acquisition mode (CAM) of a linear accelerator during treatment (Goksel, et al., 2013).