Methods of adjusting an ablation field radiating into tissue using microwave field-detecting needle assemblies

A method of adjusting an ablation field radiating into tissue, the method comprising:

• positioning an energy applicator operably coupled to an energy source into tissue;
• positioning at least one microwave field-detecting needle assembly into tissue independently from the energy applicator, the at least one microwave field-detecting needle assembly including at least one rectifier element capable of detecting microwave field intensity via rectification;
• positioning the energy applicator and the at least one microwave field-detecting needle assembly in tissue;
• transmitting energy from an energy source through the energy applicator to generate an ablation field radiating about at least a portion of the energy applicator into tissue;
• and
• adjusting the ablation field radiating about the at least a portion of the energy applicator into tissue by adjusting at least one operating parameter associated with the energy source based on at least one electrical signal transmitted by the at least one microwave field-detecting needle assembly.