Brachytherapy templates and template holders can be adjustable relative to a patient's anatomy. One template includes a disposable portion with an aperture layer that includes first apertures and a patient contact layer that includes an adhesive on a surface thereof. The patient contact layer is formed from a flexible material. The template also includes a reusable portion that includes aperture plates. A locking mechanism can lock catheters firmly in place. One template holder includes a template compartment retainer constructed to hold a brachytherapy template, and a perineum attachment component is connected to the template compartment retainer by a connecting portion. The perineum attachment component includes a perineum attachment portion formed from a flexible material.