A Critique of Research Methods in Healthcare: Evidence and Enquiry

This report critically examines the research methods employed in two studies comparing Intensity Modulated Radiation Therapy (IMRT) and Intensity Modulated Proton Therapy (IMPT) for the treatment of head and neck cancer. The report delves into various aspects of the research, including data collection, participant recruitment, sample size considerations, research quality, and database utilization. The first study, a cohort study, evaluates IMPT's superior dose distribution in advanced head and neck cancer patients, highlighting the importance of precise positioning and monitoring of anatomical changes. The second study, a retrospective analysis, compares IMRT and IMPT in patients with recurrent or primary head and neck cancer, focusing on dosimetric characteristics. The report discusses the search strategy, including the use of specific keywords and the application of the PICO framework, and considers the limitations of the studies, such as sample size and variations in tumor sites. It also highlights the similarities and differences between the two papers, discussing the methods used, including clinical evaluations, dose-volume histograms, and the comparison of PTV/CTV coverage and OAR doses. The report concludes by emphasizing the importance of further research and the need for a standardized IMPT planning strategy for head and neck cancer patients.

Module Name: Evidence and Enquiry for Practice
Assessment Title: Critique of research methods
Word Count: 2534
Introduction
Research is extremely important for health care professionals in terms of gaining knowledge
about disease trends or risk factors, treatment outcomes or public health action, functional
capacities and care patterns (Dickens, 2009). However, the Evidence-Based Practice (EBP) is
crucial because it aims to offer the most effective solutions available with the goal of
improving outcomes and decision-making. Also, EBP encourages healthcare providers to
question. The objective of this research is to compare and contrast the procedures utilised i
n two research publications in the context of
data collecting, participant recruitment, sampling size, research quality and database use.
Head and neck cancer (HNC) is the most prevalent cancer in the United Kingdom. As per the
research in the United Kingdom, it shows that males are more likely than females to develop
head and neck cancer (Cancer Research UK, 2020). Recognizing and responding to research's
ethical dimension is an important aspect of the research governance process. Concerns
about real or potential damage are reflected in ethical codes of practice and regulatory
framework (Slowther,2006).
The purpose of study
This study will investigate the difference between the IMRT and IMPT for head and neck
cancer in the organ at risk and the treatment plan in different sites of treatment by
comparing the methods used in two papers. Localised radiation therapy is limited in areas of
the head and neck, such as for a lateralized salivary gland, brain stem, spinal cord, mandible
and brachial plexus. The reason behind choosing the papers is that the sample sizes are

comparable, and both publications are recent. From 2017 through 2021, the book will be
published. The sample size is an important consideration in research because the internal
and external validity of a study are affected by a limited sample size (Faber and Fonseca,
2014).
Paper 1: However, in this study, the treatment of 31 advanced head and neck cancer
patients Intensity modulated proton therapy (IMPT) provides superior dose distribution in
Advanced head and neck cancer (HNC). IMPT can more effectively reduce the dose to
healthy tissue and thus allow for further dose escalation. On the other hand, gradual
interact-therapy changes in NHS patient anatomy, mainly caused by weight loss and
shrinkage of tumour. The dosimetrist consequences of such changes, namely the potential
under dose of target volumes and overdose in organ at risk (OARs), have been quantified in
detail for IMRT plans. Furthermore, treatment plan adaptation can be used to prevent
server dose degradation throughout the fractionated treatment course (Stützer et al., 2017).
This study underlines the precise positioning and monitoring of anatomy changes which are
mandatory for reliable IMPT treatment. Also, in consideration of the larger changes, in plan
and organ at risk dose. Is there a difference between IMRT and IMPT when treating head
and neck cancer either way in organs at risk or treatment plans?
Paper 2: Discussion is about the patient with either recurrent or primary disease of the
head and neck treated proton therapy from January 2019 to August 2020, it was
retrospectively studied. For dosimetrist comparison. Intensity modulated radiation therapy
versus intensity modulated proton therapy for treatment of head and neck cancer. In this
study to compare the 58 patients with head and neck cancer CUP treated with IMRT also,
compare the treatment plan and organ at risk. IMPT confers an advantage due to its lack of
exit dose and its deposition of maximal energy at a finite tissue depth creating a Bragg Peak.
In addition, IMRT has an exit dose and continually deposits its energy along its track. This
correlates with increased dose to OARs and may clinically relate to side effects in head and
neck cancer that include dysphagia, odynophagia, dyspepsia and xerostomia. In this study it
is aimed to compare the dosimetrist characteristic of IMRT when compared to IMPT at high-
volume in a single study with a majority of patients presenting with unilateral tumour.
Search strategy

I have utilised the Sheffield Hallam Library gateway to find search terms by using keywords
like proton therapy, radiation therapy, organ at risk in head and neck cancer patients,
treatment plan or planning, and intensity modulated radiation therapy and intensity
modulated proton therapy for dosimetrist for head and neck cancer patients to obtain both
publications. I used specific terminology to search on two papers to bring up the research
question. Also, I have ensured that the paper I have used is no more than 5 years from the
date.
Search term (PICO)
Search PICO Inclusion criteria Exclusion criteria
Population or
people (p).
Patient, head and neck cancer
patient (HNC) and participant’s
study and patients ages and site
of treatment.
Patient characteristics and CTV
size.
Treatment others site of tumour
Interest or
intervention (I)
Men or women
Radiation therapy or proton
therapy, ethical and treatment
fraction.
Comparison (C) IMRT Vs IMRT for treatment for
head and neck cancer CTV
coverage and PTV.
The advantages of the IMPT offer IMRT
treatment plan and organ sparing.
Outcome (O) Target volume changes and
quality of life.
Organ at risk (OAR) such as
salivary, spinal cord, mandible

brain stem and parotid.
Proton therapy effectively
shows treatment of NHC
patients over radiation therapy.
English language
Date ranges from 2017 to 2021
Qualitative research
Quantitative research
Cohort study
Limitation
Limiting the number of publications can have severe consequences, the most serious of
which is the withholding or failure to publish important discoveries. This may reduce the
number of non-contributing authors, but it may also constrain the scope of knowledge,
resulting in worse study quality (Deva Kumar et a.,2015).
Justification of two papers
Justification includes the Intensity modulated radiation therapy and intensity modulated
proton therapy for head and neck cancer patients either in primary or advance tumour in
different areas in head and neck such as Oral cavity tongue, oropharynx, hypopharynx,
larynx and salivary gland tumour. However, the advanced radiotherapy technique is playing
an important role for management.
Comparison between two papers in research methods
Difference

Paper:1 Cohort studies
Bias in the sampling of the cohort study.
Collecting prospective data and Missing data.
All patients gave their written consent form, and the local ethic committee approved the
study. The clinical data are not available for IMPT. The study needs to be considered for
future studies to be completed into clinical practice.
Similarities
Both the papers discuss the organ at risk. Both papers used male and female.
Both studies used small sampling sizes with both IMPT & IMRT treatment plans and
treatment delivered to organs at risk and that shows effects succeeded.
Paper:2
Qualitative study.
This study compared patients treated with IMRT and IMPT from January 2019 to August
2020, either recurrent, benign or metastatic disease. Small in size, there were only 29
patient’s participants with trials. Ages of the patients ranged from 15 to 89; the majority
of the patients were male. The study used concurrent chemotherapy with IMPT and IMRT.
Methods of discussion
The term "research methods" refers to a set of procedures for gathering and analysing data.
A sample size that is too small reduces the study power and increases the margin of error,
perhaps resulting in the study worthless. However, limiting the sample size reduces the
study confidence level. The term’s reliability and validity are used to assess the quality of
research. On the other side, reliability refers to consistency, while validity refers to its
accuracy (Litwin et al.,2017).

The limitation of this study includes sample size, variation in specific tumour sites and
histologist and lack of matched clinical controls to determine whether it is a therapeutic
advantage of IMRT. The proton machine began operating from January 2019 to August
2020. The sample size used is limited to patients treated in the 1.5 years. Further analysis is
warranted in the future after the accumulation of more patients with head and neck cancer
patients who are treated with IMPT thus a preliminary analysis that will need further follow-
up in this assortment of case OARs of concern varied for a patient. For example,
nasopharyngeal primaries, optic structures were cancers, and oral cavity. The contralateral
parotid was of the highest priority. Also, the patient’s population grows. However, there will
need to separate patients based on subsides and analyse them further (Nguyen et al.,2021).
Qualitative research, which takes a humanistic or idealistic approach to understand a study
question, can make a significant contribution to health. To better understand people's
views, experiences, attitudes, behaviours, and interactions, qualitative methodologies are
applied. Qualitative research should be well-designed, with the study goals and procedures
rigorously adjudicated (Kalra et al., 2013). A qualitative researcher's facing difficulty to give a
visual representation of the data, which might be huge and confusing and must make sense
of several perspectives or complex situations. Although qualitative data analysis is inductive
and focused on meaning, there are many various ways to data analysis, each with it is the
aim, ontological and epistemological underpinnings. Identifying a recurring and noteworthy
theme, which entails searching data for patterns in order to produce an illuminating account
of a phenomenon, is a key skill in qualitative research data analysis (Noble and Smith, 2013).
When qualitative research is integrating with quantitative data, it can provide a deeper
understanding of health-related concerns. Cohort studies are a type of research that tracks
participants across time. Cohort studies recruit and follow participants that share a common
trait, such as a comparison with the demographic profile. Some members of the cohort will
be exposed to a specific risk factor or characteristic over the follow-up period, and by
measuring outcomes across time, it will be possible to investigate the effects of this variable
(Barrett and Noble, 2019).
Methods discussion paper:1

In each plan was shown a clinical evaluation of normal tissue that showed effects in the
clinic, as well as normal tissue dose-volume histograms (DHs). The Varian Eclipse treatment
planning system was used to plan IMRT and IMPT treatment. PTV for IMRT and CTV for
IMPT were compared in terms of minimum, maximum, and mean doses. The maximums and
dosages of various OARs were also investigated. Many essential structures in the head and
neck are at risk of toxicities and side effects as a result of radiation therapy. Proton therapy
has evolved as a method for reducing the dosage to OARs while still providing coverage for
identified tumour locations. However, IMRT and IMPT plans were compared in patients to
compare PTV/CTV coverage and OAR doses. In the majority of patients, the dosimetrist
advantage was found in mean dosages to the con-trilateral parotid gland, oral cavity, and
larynx. It is unclear whether this is clinically beneficial. Sparing the contralateral parotid
gland, oral cavity, and larynx from the dose would theoretically benefit salivary function and
reduce mucositis. However, doses to OARs in both IMPT and IMRT plans fulfilled planning
objectives, raising the question of whether there is a financial incentive to optimise OARs to
lower doses (Romesser et al., 2016).
Methods discussion paper:2
For correlation analyses of doses to organs at risk, IMRT treatment plans were compared to
IMPT treatment plans. In this investigation, the highest dose increase in various OARs for
IMPT NHC treatment was linked to a positive clinical outcome for patients with less
advanced NHC. In IMRT investigations, however, it was discovered that the target dose
parameter increased dramatically but remained mainly within requirements, whereas the
rise in OAR was somewhat critical for the parotid glands. The diversity of IMPT OAR dose
changes was slightly higher, although it remained far below con-strains. Although inter-
observer variability in contouring may be a concern for this study, which used the same
contours for IMRT and IMPT and found that setup errors and anatomical changes had a
different impact on both modalities. However, the findings of this study should be taken
into account in future research and clinical practice. Furthermore, there is no universal
agreement on the best IMPT planning strategy for HNC patients in that comprehensive
optimisation cannot yet be deemed a clinical standard. IMPT plans may be inferior to the
best available on the market, but they are not unrealistic to the best of their knowledge. As

a result, the study's finding of clear IMPT dose deterioration in control CT should be
interpreted as an appeal to make every effort to guarantee that proton therapy is delivered
safely and reliably (Kraan et al., 2015).
Strength of a cohort study
The exposure variable, other variables, and outcomes may be quantified more precisely in a
prospective cohort study. It is critical to keep exposure and result measurements consistent.
When contrasted to prospective cohort studies, a retrospective cohort study can be
performed quickly. It does, however, have the advantages of a prospective cohort study.
Limitation of cohort study
A prospective cohort design has several disadvantages, including the fact that it is time
intensive and expensive. Another disadvantage of these studies is the loss of participants
over time. In a retrospective cohort study, on the other hand, the exposure and outcome
variables are obtained before the study begins (Setia, 2016). However, disadvantages of
cohort study, there are various practical and inferential issues with cohort studies. To begin
with, cohort studies on tumours with low incidence rates are not suitable for inferring
causal links since a large number of events must be accumulated over a long period of time.
Randomized controlled trials, on the other hand, are well suited to examining steady
exposures across time. Only baseline exposure data is gathered, and it is utilised to create
distinct exposure groups (Dag, 2015).
Conclusion
It is concluded that evidence and inquiry for practice is an important concept to learn and
study in order to critique the research methods so that research papers can be reviewed in a
systematic manner and in an appropriate manner. This report covers the topic of healthcare
professionals on which the research is done in order to gain the knowledge about various
risk factors and their treatments. There are basically two research papers which are studied
in this report such as in the first paper the treatment of head and neck cancer patients is
studied along with the IMPT and IMRT treatment. Second paper has the discussion all about
the primary diseases of head and neck patients along with their causes and consequences
which is followed by the treatments as well. Moreover, the purpose of the study is also
discussed along with the search strategy of these two papers and also the different types of

medical and biological search terms which are used in the research papers and review which
includes inclusion criteria and exclusion criteria. Limitation of the papers are also discussed
along with the justification of these two papers and also the comparison between these two
papers are also conducted in terms of research methods which includes the differences and
similarities and also the methods of discussions as well in both the papers individually. The
most important cohort study is also conducted which includes the strength and limitation of
the study. The proper review paper consists of all these things in order to better understand
the concept of the research paper which is studied in the report so that the proper research
methodologies can be better known along with the topics on which the investigation is
conducted. Hence this report covers all such areas in order to better understand the health
care professional topic in the form of research and review papers.
Reference list:
Barrett, D. and Noble, H., 2019. What are cohort studies? Evidence Based Nursing, 22(4),
pp.95-96.
Cancer Research UK. (2020) about/-cancer/head-neck-cancer
nhttps://www.cancerresearchuk.org/about-cancer/head-neck-cancer
Devakumar, D., Shikanai Yasuda, S. and Sutaria, S., 2015. The limits of research. Journal of
the Royal Society of Medicine, 108(5), pp.199-200.
Dickens, B., 2009. Distinguishing Public Health Activities from Public Health Research: A
Discussion Paper on Public Ethics Oversight. SSRN Electronic Journal
Dag S. Thelle, Petter Laake. (2015).in Research in Medical and Biological Sciences (Second
Edition),

Faber, J. and Fonseca, L., 2014. How sample size influences research outcomes. Dental Press
Journal of Orthodontics, 19(4), pp.27-29.
Kalra, S., Pathak, V. and Jena, B., 2013. Qualitative research. Perspectives in Clinical
Research, 4(3), p.192.
Karan, A., van de Water, S., Teguh, D., Al-Mamgani, A., Madden, T., Kooy, H., Heijmen, B.
and Hoogeman, M., 2013. Dose Uncertainties in IMPT for Oropharyngeal Cancer in the
Presence of Anatomical, Range, and Setup Errors. International Journal of Radiation
Oncology*Biology*Physics, 87(5), pp.888-896.
Litwin, S., Basickes, S. and Ross, E., 2017. Two-sample binary phase 2 trials with low type I
error and low sample size. Statistics in Medicine, 36(9), pp.1383-1394.
Nguyen, M., Cantrell, J., Ahmad, S. and Henson, C., 2021. Intensity-modulated proton
therapy (IMPT) versus intensity-modulated radiation therapy (IMRT) for the treatment of
head and neck cancer: A dosimetrist comparison. Medical Dosimetry,
Noble, H. and Smith, J., 2013. Qualitative data analysis: a practical example. Evidence Based
Nursing, 17(1), pp.2-3. Romesser, P., Cahlon, O., Scher, E., Zhou, Y., Berry, S., Rybkin, A.,
Sine, K., Tang, S., Sherman, E., Wong, R. and Lee, N., 2016. Proton beam radiation therapy
results in significantly reduced toxicity compared with intensity-modulated radiation
therapy for head and neck tumour that require ipsilateral radiation. Radiotherapy and
Oncology, 118(2), pp.286-292.
Slowther, A., Boynton, P. and Shaw, S., 2006. Research Governance: Ethical Issues. Journal
of the Royal Society of Medicine, 99(2), pp.65-72.

Setia, M., 2016. Methodology series module 1: Cohort studies. Indian Journal of
Dermatology, 61(1), p.21.
Stützer, K., Jakobi, A., Bandurska-Luque, A., Barczyk, S., Arnsmeyer, C., Löck, S. and Richter,
C., 2017. Potential proton and photon dose degradation in advanced head and neck cancer
patients by intratherapy changes. Journal of Applied Clinical Medical Physics, 18(6), pp.104-
113.
Appendix
Appendix Is there any difference between IMRT vs IMPT for
head and neck cancer? Organ at risk or treatment.

Introduction 2/3
Limitation and samples 4
Exclusion and inclusion
tables
5
Justification of choice of
papers
5
Purpose of discussion 6
Paper:1 6
Paper:2 7
Similarities and difference 8
Methods discussion 9/10
Conclusions 11, 12
Reference list 13
Appendix 14