Thesis Title Title –Volumetric and dosimetric comparison of gross tumor volumes between PET-CT and CT simulation images in head and neck radiotherapy planning Investigator – Dr. Kundavai Seran Guide – Dr. Nalini Rao Department- Radiation oncology Healthcare Global Enterprises Ltd

Introduction FDG PET-CT is a functional imaging modality used commonly in the diagnosis and staging of malignancies with high sensitivity and specificity Radiation treatment planning can be done with various imaging modalities like CT, PET fused with CT, MRI. PET-CT based planning has the advantage of combining both anatomical and functional imaging. Healthcare Global Enterprises Ltd

Rationale for the study CT simulation is widely practiced for radiation treatment planning There are certain disadvantages to CT based treatment planning, such as - reduced soft tissue contrast - lack of functional information The lack of functional information can be overcome by using imaging modalities like PET-CT for treatment planning. Healthcare Global Enterprises Ltd

PET-CT based treatment planning is recommended as a standard practice in lung malignancies (Current concepts in F18 FDG PET/CT-based radiation therapy planning for lung cancer Percy Lee,* Patrick Kupelian, Johannes Czernin, and Partha Ghosh) This concept can be applied in head and neck cancer so as to provide better volume delination while sparing more normal tissue and also escalate dose to areas with high metabolic activity resulting in higher tumor control

Research Hypothesis PET-CT based gross tumor volumes are smaller in comparison to their CT counterparts. Thus providing better normal tissue sparing, reduced geographical miss of tumor and possible dose escalation to the areas of high metabolic activity Healthcare Global Enterprises Ltd

Aims To establish the concordance between PET-CT and CT based contouring of gross tumor volumes in head and neck radiotherapy planning Healthcare Global Enterprises Ltd

Objectives PRIMARY OBJECTIVE SECONDARY OBJECTIVE To compare the gross tumor volumes (GTV) identified on CT simulation images to that obtained from FDG PET-CT and determine the differences in volumes and dose coverage of PET-GTV and CT-GTV in head and neck radiation treatment planning SECONDARY OBJECTIVE Dosimetric comparison of the organs at risk between the PET-CT and CT based treatment plans in head and neck cancers. Healthcare Global Enterprises Ltd

Review of Literature 1. Combined FDG PET-CT imaging in radiotherapy target delineation for head and neck cancer ALESSANDRA GUIDO, M.D.,* LORENZO FUCCIO, M.D.,y BARBARA ROMBI, M.D.,* PAOLO CASTELLUCCI, M.D.,z AGNESE CECCONI, M.D.,* FEISAL BUNKHEILA, M.D.,* CHIARA FUCCIO, M.D.,z EMILIANO SPEZI, PH.D.,* ANNA LISA ANGELINI, PH.D.,* AND ENZA BARBIERI, M.D.* For 38 head and neck squamous cell carcinoma patients, FDG PET and CT was performed in 1 session and images were fused Patient underwent CT based treatment planning. Gross tumor volumes were defined using both PET-CT and CT images Conclusion- GTV was significantly changed(reduced) by using PET-CT based planning Healthcare Global Enterprises Ltd

2.FDG PET-CT imaging for staging and radiation treatment planning fornhead and neck cancers Letizia Deantonio,1 Debora Beldì,1 Giuseppina Gambaro,1 Gianfranco Loi,2 Marco Brambilla,2 Eugenio Inglese,3 andMarco Krengli 22 patients with head and neck cancers underwent both CT and PET-CT simulation Corresponding gross tumor volumes (GTV) were contoured in each simulation image ie PET-CT-GTV and CT-GTV Conclusion- PET-CT incorporation led to change in staging as well as reduction of GTV and could have a potential impact in radiation treatment planning.

3.Primary tumor delineation based on 18FDG PET for locally advanced head and neck cancer treated by chemo-radiotherapy MathieuLeclercabEricLartigaucThomasLacorneriecJean-FrançoisDaisnedAndrewKramareVincentGrégoirea 41 head and neck cancer patients to be treated by upfront radiotherapy were taken. Treatment volumes such as GTV, CTV, PTV were contoured on CT and PET simulation images. Corresponding treatment plans were generated. Volumetric and dosimetric comparison between the 2 treatment plans were carried out

Conclusion All treatment volumes ie. GTV, CTV and PTV were significantly smaller in the PET based plan compared to their CT counterparts. The dosimetry comparison showed a significant decrease in parotid and oral cavity mean dose from the PET-based plans.

Materials and Methods Study area- HCG hospital, KR road, Bengaluru Study population- 30 patients diagnosed with head and neck cancers who were planned for external beam radiation with or without chemotherapy Healthcare Global Enterprises Ltd

Type of Study Study design -Longitudinal Observational Single Institute Study. Study duration- november 2017- june 2019 Healthcare Global Enterprises Ltd

Statistics - sample size Expected proportion – 0.92 Precision (%)- 10 Desired confidence level (1-apha)%- 95 Required sample size- 30 Healthcare Global Enterprises Ltd

Estimating single proportion(absolute precision) Formula Where, P: expected proportion d: absolute precision 1- alpha/2: desired confidence interval

Ethical Aspects Healthcare Global Enterprises Ltd

Inclusion criteria All histopathologically proven patients of squamous cell carcinoma of Head and neck (Oral cavity, Post 1/3 rd of Tongue, Oro pharynx, hypopharynx, Supraglottic larynx, Larynx, Laryngopharynx) Early stage and locally advanced diseases (Stage I – III) Planned for upfront external beam radiation with or without concurrent chemotherapy ECOG 1-4

Exclusion criteria Head and neck cancer patients taken up for neoadjuvant chemotherapy or surgery. Stage IV C disease (AJCC) Patients receiving re-irradiation Patients not consenting for study

Materials and Methods Primary data collection Informed consent. Details of clinical history and physical examination. Baseline Blood investigations including Complete blood profile, Liver Function test, Renal function test. Radiological investigations including Chest X ray, USG, PET/ CT scan. Pathological confirmation with biopsy Clinical Diagnosis and Staging of diseases. Planning PET and CT simulation images. Healthcare Global Enterprises Ltd

Methodology Contouring GTV in PET images (threshold suv>40%) Comparing PET-CT-GTV and CT-GTV Dosimetric comparison of organ at risk between the 2 corresponding treatment plans

References Nishoika T, Shiga T, Shirato H, et al. Image fusion between 18FDG-PET and MRI/CT for radiotherapy planning of oropharyngeal and nasopharyngeal carcinomas. Int J Radiat Oncol Biol Phys. 2002;53:1051–1057. Christopher Scarfone, PhD; William C. Lavely, MD; Anthony J. Cmelak, MD; Dominique Delbeke, MD; et al. Prospective feasibility trial of radiotherapy target definition for head and neck cancer using 3-dimensional PET and CT imaging. J Nucl Med 2004; 45:543–552 Paulino, A.C., Koshy, M., Howell, R. et al, Comparison of CT- and FDG-PET-defined gross tumor volume in intensity-modulated radiotherapy for head-and-neck cancer. Int J Radiat Oncol Biol Phys. 2005;61:1385–1392 Wang, D., Schultz, C.J., Jursinic, P.A. et al, Initial experience of FDG-PET/CT guided IMRT of head-and-neck carcinoma. Int J Radiat Oncol Biol Phys. 2006;65:143–151 Ciernik, I.F., Dizendorf, E., Baumert, B.G. et al, Radiation treatment planning with an integrated positron emission and computed tomography (PET/CT): A feasibility study. Int J Radiat Oncol Biol Phys. 2003;57:853–863 Katie l. Newbold, Mike Partridge, Gary Cook, et al. Evaluation of the role of FDG PET-CT in radiotherapy target definition in patients with head and neck cancer. Acta Oncologica, 47:7, 1229-1236 Healthcare Global Enterprises Ltd