Current advances in colorectal cancer treatment

Abstract

The general aim of this thesis was to examine current advances in the treatment of colorectal cancer. The first part of this thesis is focused on new application of existing treatment in patients with stage IV CRC. Chapter 2 evaluates the feasibility and effectiveness of short-course pelvic radiotherapy (5 x 5 Gy) followed by systemic therapy and local treatment of all tumor sites in potentially curable stage IV rectal cancer patients in daily practice. A multicenter retrospective study is performed, evaluating the completion rate of the full treatment schedule, symptom control of the primary tumor and survival. 16 Chapter 1 In Chapter 3, high dose Stereotactic Body Radiation Therapy (SBRT) is compared to low dose SBRT for hepatic metastases. The aim of this study is to evaluate the efficacy and safety of high versus low dose SBRT in patients with liver metastases and to determine prognostic variables on local control and overall survival. Chapter 4 describes a prospective, randomized controlled pilot study conducted in the Netherlands Cancer Institute and examines if neoadjuvant chemotherapy and/or targeted therapy in patients with unresectable liver metastases can inhibit the growth of the metastases induced by the primary tumor resection. The second part of this thesis is focused on new surgical techniques for localized CRC surgery. Chapter 5 includes an ex vivo study investigating the use of hyperspectral imaging for tissue classification in CRC. Tissue samples from CRC surgery were imaged with two hyperspectral cameras. The ultimate goal is to develop a real-time technique for tissue identification in colorectal surgery. In Chapter 6 and 7, a different intraoperative imaging technique is evaluated. Chapter 6 evaluates whether image-guided navigation during locally advanced primary or recurrent rectal cancer surgery can improve resection margin rates compared to rectal surgery without navigation. The study compares the clinical outcomes of patients from a prospective, single-arm study with patients from a historical cohort. Chapter 7 explores the feasibility of real-time tumor tracking with image-guided navigation in patients with non-fixed mobile rectal tumors. An electromagnetic tracking system is used to real-time track the rectal tumor during the course of surgery.