Clinical Research Directory

Inclusion Criteria: * Patients who have completed treatment for cancer (\*with the exception of long-term adjuvant endocrine therapy). * Subjective Impairment due to Cancer-Related Fatigue (CrF) . NCCN-recommended questions are used for screening ("How exhausted do you feel on a scale of 0 to 10?" and "How impaired do you feel by this fatigue on a scale of 0 to 10?" (threshold \>4 on either scale). * At the time of study inclusion, it must be expected that no further antitumor therapy measures will be started within the next 6 months. * Patients must be able to refrain from smoking up to 15 minutes before the intervention (smoking within 15 minutes before therapy impairs the participant's ability to perceive the aroma of the phytoncides). * Written and valid informed consent from the patient. Exclusion Criteria: * Presence of inadequately controlled major depression in the opinion of the investigator. * Asthma (inhaled phytoncides may cause airway irritation, exacerbation of asthma, or bronchoconstriction). * Known allergy to pine or citrus fragrance. * Anosmie. * Medical history of seasickness (virtual reality can cause nausea/vomiting with no improvement after 5-10 minutes). * History of seizures (virtual reality may increase susceptibility to seizures due to the changing light in the forest video). * Visual and hearing impairments that are not corrected by visual or hearing aids. * Unwillingness to store and share personal medical data as part of the protocol. * Participation in another clinical trial focusing on behavioural or complementary medicine interventions. * Missing or incomplete consent form.