1. To learn about different methods to assess the tumour response in the colorectal metastases.
2. To understand usefulness and limitation of techniques and the role of different contrast media.
3. To appreciate the variable response pattern of colorectal liver metastases.
Colorectal liver metastases (CRLM) occur in nearly half of the patients with colorectal cancer. Neoadjuvant chemotherapy (NAC) is the treatment of choice. Surgical resection and locoregional control have evolved as treatment options in the patients with single or oligometastatic disease and in those who show excellent response to NAC. The number,location and response of CRLM are critical in determining their surgical resection. Assessment of treatment response of CRLM to NAC and locoregional treatment is therefore very important to provide guidance for their management. Standard methods of assessment (RECIST) use size (one-dimensional, bi-dimensional, volume) and a reduction in the size is considered a response. However there are pitfalls to these methods and they will highlighted during the presentation. Variable responses of CRLM and to different chemotherapy regimens add another dimension to complexity of assessment of the response. The most important information is a viable or a residual tumour which tumour size alone cannot predict but can be assessed with additional information from dynamic contrast-enhanced MRI (DCE-MRI), diffusion-weighted imaging (DWI), positron emission tomography (PET). NAC and some locoregional treatment also cause liver toxicity including sinusoidal obstruction syndrome (SOS), chemotherapy-associated steatohepatitis (CASH) or simple fatty change that can influence the assessment of response. In this presentation, an overview of response of CRLM to treatment will be presented and this will be followed by review of different methods for response assessment including their limitations and advantages.
1. To learn about the rationale for neoadjuvant treatment in rectal cancer and the impact on subsequent surgery.
2. To understand why imaging is needed to assess the response to neoadjuvant therapy, what to look for when judging response and where the challenges lie.
3. To appreciate when surgery can be deferred or avoided and how to best follow-up on these patients.
MRI is the modality of choice for restaging rectal cancer. The high soft-tissue contrast of MRI can accurately assess the extramural tumour spread and relation to surrounding structures after chemoradiation. This lecture will have a practical approach to determining the role of MRI in the restaging of rectal cancer. The relevant anatomy, MRI techniques, the rationale for neoadjuvant treatment, and post-chemoradiation therapy imaging (including detection of patients with a complete response) will be discussed with special attention to how to apply recent advances in knowledge to daily clinical practice.
1. To understand the rationale for neoadjuvant treatment in pancreatic adenocarcinoma.
2. To learn the limitations of CT in assessing treatment response.
3. To learn how to accurately select patients for curative-intent surgery after neoadjuvant therapy.
Pancreatic ductal adenocarcinoma (PDA) remains among the most challenging malignancies to treat. At diagnosis, the tumour often already extends beyond the confines of the pancreas, spreading to an extent such that primary surgery with curative intent is very rarely feasible. Considerable momentum is now being given to a treatment strategy involving neoadjuvant chemotherapy or chemoradiotherapy in patients with nonmetastatic PDA. The main advantage of this strategy is a better selection of patients likely to benefit from curative-intent surgery via the achievement of negative resection margins. Patients with a rapidly progressive disease are identified and spared ineffective surgery with its attendant morbidity. Neoadjuvant therapy can convert tumours classified as locally advanced by initial imaging studies to resectable tumours. However, the imaging study evaluation of the response to neoadjuvant therapy is extremely complex. Thus, the diagnostic performance of imaging studies is not sufficient to ensure the accurate selection of patients in whom negative-margin resection is likely to be achieved. More specifically, standard criteria for predicting vascular invasion, based on the amount of tumour-vessel contact, are not valid after neoadjuvant therapy.