I now have full content of the thesis proposal. Let me write the Merits section for this research.

Here are the Merits of the Proposed Research Work for Dr. Anshuman Chechi's thesis:

Topic: Diagnostic Evaluation of Dual Time Point ¹⁸F-FDG PET/CT versus Single Time Point Whole Body Diffusion Weighted MRI to Differentiate Mediastinal Lymph Node Metastasis in Patients with Non-Small Cell Lung Cancer (NSCLC)

Lung carcinoma is one of the leading causes of cancer-related mortality worldwide. Accurate mediastinal lymph node staging directly determines treatment planning - whether a patient is eligible for surgery, receives concurrent chemoradiotherapy, or palliative care. The research targets a high-impact clinical question with direct patient management implications.

The study is designed as a prospective observational study in which both dual time point (DTP) ¹⁸F-FDG PET/CT and whole body diffusion weighted MRI (DWI-MRI) are performed in the same patient cohort. This within-patient comparative design eliminates inter-group confounders and provides a robust, direct comparison of the two imaging modalities - a methodological strength that most existing retrospective or single-modality studies lack.

The review of literature explicitly identifies that few studies directly compare DTP ¹⁸F-FDG PET/CT with dedicated single-setting MRI protocols in the same patient cohort for mediastinal staging in lung cancer. This research fills that specific gap, making it an original contribution to the field of nuclear medicine and oncologic imaging.

Standard single time point PET/CT has well-documented limitations, including false positives from inflammatory or granulomatous diseases and false negatives in small or low-FDG-avid nodes. DTP PET/CT exploits differential FDG kinetics - malignant lesions show continued FDG accumulation while benign lesions show stable uptake or washout - thereby improving diagnostic differentiation. The meta-analysis cited (Shen et al., 2015; 654 patients) confirms DTP PET/CT shows better sensitivity (85% vs 79%) and per-lesion specificity (89% vs 83%), validating the merit of this imaging approach.

The inclusion of whole body DWI-MRI as a comparator is scientifically and ethically significant. DWI-MRI provides functional tissue characterization through ADC (Apparent Diffusion Coefficient) values without any ionizing radiation. This is particularly valuable for younger patients, those requiring serial imaging, or patients where radiation dose minimization is a concern.

The study evaluates objective, reproducible quantitative parameters:

The use of quantitative imaging biomarkers rather than purely subjective visual interpretation enhances reproducibility, reduces operator bias, and increases the scientific rigor of the findings.

A secondary objective focuses on reducing equivocal findings - a major problem in current practice where indeterminate lymph nodes lead to unnecessary biopsies, delays in treatment, or misclassification of stage. By demonstrating the complementary roles of both techniques, the research can guide clinicians on whether to adopt a combined protocol or select one modality over the other in specific clinical settings.

All patients in the study have histopathologically proven NSCLC, and final imaging findings are correlated against biopsy or histopathology results. This gold-standard validation makes the diagnostic performance metrics (sensitivity, specificity, PPV, NPV) clinically reliable and publishable.

The sample size of 90 patients (79 calculated + 10% attrition) is derived from a validated statistical formula at 95% confidence interval. Diagnostic metrics will be reported with 95% CI, and Kappa statistics will assess inter-observer agreement - ensuring the study findings meet the standards expected of a high-quality diagnostic accuracy study.

The study protocol incorporates full institutional ethics committee approval, a structured informed consent process (in English with witness signatures), a detailed Case Record Proforma, and a Data Collection Sheet. This compliance with Good Clinical Practice (GCP) standards ensures the research can be published in peer-reviewed journals and its findings can be safely translated to clinical practice.

The study will be conducted at NIMS University, Jaipur - a dedicated medical sciences institution with Nuclear Medicine, PET/CT, and MRI facilities. The 18-20 month time frame and purposive sampling from the cancer OPD are realistic for a resident research project, making successful completion of the study highly feasible.

This research work is meritorious because it is original, prospective, uses gold-standard histopathological validation, compares two advanced imaging modalities head-to-head in the same patients, uses quantitative biomarkers, and has direct implications for improving staging accuracy and reducing unnecessary invasive procedures in NSCLC patients. The findings will contribute meaningfully to the growing body of evidence on optimizing mediastinal nodal evaluation in lung cancer.

This prospective study addresses a clinically significant gap, as very few studies have directly compared dual time point ¹⁸F-FDG PET/CT with whole body DWI-MRI in the same patient cohort for mediastinal nodal staging in NSCLC. By exploiting differential FDG kinetics (SUVmax, Retention Index) alongside ADC values from MRI, the study uses objective quantitative biomarkers rather than subjective visual interpretation, enhancing reproducibility and diagnostic accuracy. The inclusion of a radiation-free MRI arm offers a clinically valuable alternative, especially for patients requiring repeated imaging. All findings are validated against histopathology as the gold standard, ensuring reliable diagnostic performance metrics. The prospective design, adequate sample size (n=90) with 95% CI, and full ethical compliance make the results robust, reproducible, and suitable for publication in peer-reviewed journals.