A - B of terms

ABLATION: A medical technique whereby a needle, containing a heating device or other element at its end, is placed through the skin into a tumour using imaging guidance. Typically the tumour is then burned off or frozen depending on the particular type of ablation being used. Different types of ablation include: CRYOBLATION, MICROWAVE ABLATION (MWA) or RADIOFREQUENCY ABLATION (RFA).

ADAPTIVE TRIAL: A type of CLINICAL TRIAL where learning takes place from previous results whilst the trial is ongoing. Where trial arms are seen to be effective or less effective the trial arms are tweaked to accelerate potential promising treatments and to drop or reduce those that seem less effective.

ADJUVANT: A therapy given after initial treatment for the primary cancer. The intention of an adjuvant therapy is to prevent future metastatic disease (spread of the disease).

ADVERSE REACTION or ADVERSE EVENT: Also known as side effects, adverse reactions include any undesired actions or effects of the experimental drug or treatment. Experimental treatments must be evaluated for both immediate and long-term side effects.

APPROVAL: A drug, device or biologic must be approved by a countryʼs regulatory agency before it can be marketed. The approval process involves several steps including preclinical (animal) studies, clinical trials for safety and efficacy, filing of a New Drug Application (NDA) in the United States or Marketing Authorization Application (MAA) in Europe by the manufacturer, regulatory agency review of the application, and agency approval/rejection of application.

ARM: Any of the treatment groups in a clinical trial. Most randomized trials have two “arms,” but some have three “arms,” or even more.

BASELINE: Baseline information is gathered at the beginning of a study from which variations found in the study are measured. Baseline can also be described as a known value or quantity with which an unknown is compared when measured or assessed. Safety and efficacy of a drug are often determined by monitoring changes from the baseline values.

BAYESIAN TRIAL: see ADAPTIVE TRIAL

BIAS: When a point of view prevents impartial judgment on issues relating to the subject of that point of view. In clinical studies, bias is controlled by blinding and randomization.

BLIND, BLINDED or BLINDING: A clinical trial is “blinded” if the participants are unaware on whether they are in the experimental or control arm of the study. Blinding may also be extended to the investigators so that their patient observations are less likely to be biased by their awareness of the treatment the patient is receiving.

BRACHYTHERAPY: A radiotherapy treatment for primary ocular (uveal) melanoma which involves attaching a round radioactive metal plaque to the outside of the eyeball. The plaque is left in place for a couple of days to burn off the tumour which is situated on the inside of the eye in the same location as the plaque has been attached. This treatment is usually sight-saving although some residual radiation damage will often occur. Its availability is dependent on the size and shape of the tumour as well as its location.