[Choosing wisely recommendations in hematology and oncology].

Many new diagnostic and therapeutic options have been introduced in the field of hematology and medical oncology during recent years. Rational treatment recommendations are thus of even greater importance. Five presumably underused measures are recommended (positive recommendations), primarily pertaining to supportive therapy, but also concerning the selective use of molecular diagnostics. Recommendations to avoid unnecessary procedures (negative recommendations) involve a possible excessive use of anticancer therapy and imaging, and insufficiently selective use of growth factors, antiemetics, and targeted therapies.