Dose escalation guided by 18F-FDG PET/CT for esophageal cancer

Tumor microenvironment and fibroblast activation protein inhibitor (FAPI) PET: developments toward brain imaging

Fibroblast activation protein (FAP) is a type-II membrane bound glycoprotein specifically expressed by activated fibroblasts almost exclusively in pathological conditions including arthritis, fibrosis and cancer. FAP is overexpressed in cancer-associated fibroblasts (CAFs) located in tumor stroma, and is known to be involved in a variety of tumor-promoting activities such as angiogenesis, proliferation, resistance to chemotherapy, extracellular matrix remodeling and immunosuppression. In most cancer types, higher FAP expression is associated with worse clinical outcomes, leading to the hypothesis that FAP activity is involved in cancer development, cancer cell migration, and cancer spread. Recently, various high selectivity FAP inhibitors (FAPIs) have been developed and subsequently used for positron emission tomography (PET) imaging of different pathologies. Considering the paucity of widely available and especially mainstream reliable radioligands in brain cancer PET imaging, and the poor survival rates of patients with certain types of brain cancer such as glioblastoma, FAPI-PET represents a major development in enabling the detection of small primary or metastatic lesions in the brain due to its biological characteristics and low background accumulation. In this work, we aim to summarize the potential avenues for use of FAPI-PET, from the basic biological processes to oncologic imaging and with a main focus on brain imaging.

SCOPE 2 - Still Answering the Unanswered Questions in Oesophageal Radiotherapy? SCOPE 2: a Randomised Phase II/III Trial to Study Radiotherapy Dose Escalation in Patients with Oesophageal Cancer Treated with Definitive Chemoradiation with an Embedded Phase II Trial for Patients with a Poor Early Response using Positron Emission Tomography/Computed Tomography

The SCOPE 2 trial of definitive chemoradiotherapy in oesophageal cancer investigates the benefits of radiotherapy dose escalation and systemic therapy optimisation. The trial opened in 2016. The landscape of oesophageal cancer treatment over the lifetime of this trial has changed significantly and the protocol has evolved to reflect this. However, with the recent results of the Dutch phase III ART DECO study showing no improvement in local control or overall survival with radiotherapy dose escalation in a similar patient group, we sought to determine if the SCOPE 2 trial is still answering the key unanswered questions for oesophageal radiotherapy. Here we discuss the rationale behind the SCOPE 2 trial, outline the trial schema and review current data on dose escalation and outline recommendations for future areas of research.

MR-Guided Adaptive Radiotherapy for OAR Sparing in Head and Neck Cancers

Simple Summary

Normal tissue toxicities in head and neck cancer persist as a cause of decreased quality of life and are associated with poorer treatment outcomes. The aim of this article is to review organ at risk (OAR) sparing approaches available in MR-guided adaptive radiotherapy and present future developments which hope to improve treatment outcomes. Increasing the spatial conformity of dose distributions in radiotherapy is an important first step in reducing normal tissue toxicities, and MR-guided treatment devices presents a new opportunity to use biological information to drive treatment decisions on a personalized basis.

Abstract

MR-linac devices offer the potential for advancements in radiotherapy (RT) treatment of head and neck cancer (HNC) by using daily MR imaging performed at the time and setup of treatment delivery. This article aims to present a review of current adaptive RT (ART) methods on MR-Linac devices directed towards the sparing of organs at risk (OAR) and a view of future adaptive techniques seeking to improve the therapeutic ratio. This ratio expresses the relationship between the probability of tumor control and the probability of normal tissue damage and is thus an important conceptual metric of success in the sparing of OARs. Increasing spatial conformity of dose distributions to target volume and OARs is an initial step in achieving therapeutic improvements, followed by the use of imaging and clinical biomarkers to inform the clinical decision-making process in an ART paradigm. Pre-clinical and clinical findings support the incorporation of biomarkers into ART protocols and investment into further research to explore imaging biomarkers by taking advantage of the daily MR imaging workflow. A coherent understanding of this road map for RT in HNC is critical for directing future research efforts related to sparing OARs using image-guided radiotherapy (IGRT).