Method for determining the effect of a selected treatment administered to a patient, which includes the procedures of acquiring VOC-emission-data of pre-treatment-target-cells-cultures and producing a pre-treatment-target cells-VOC-profile from the VOC-emission of the pre-treatment-target-cells-cultures. Producing an MCD-target-cells-VOC-profile by: (a) inducing MCD on non-treated target-cells-cultures thereby producing post-MCD-target-cells-cultures； and (b) acquiring VOC-emission-data of the post-MCD-target-cells-cultures. Applying the selected treatment to target-cells-cultures and acquiring VOC-emission-data of post-treatment-target-cells-cultures and determining the effect of the selected treatment. The treatment is determine as effective when: (a) concentration values from VOC-emission-data of pre-treatment-target-cells-cultures, of VOCs associated with the pre-treatment-target-cells-VOC-profile, are greater than concentration values from the VOC-emission-data of post-treatment-target-cells-cultures, of VOCs associated with the pre-treatment-target-cells-VOC profile； and (b) concentration values from VOC-emission-data of post-treatment-target-cells-cultures, of VOCs associated with the MCD-target-cells-VOC-profile, emitted by the post- treatment-target-cell-cultures, are greater than concentration values from the VOC-emission-data of pre-treatment-target-cells-cultures, of VOCs associated with the MCD-target-cells-VOC-profile, emitted by the pre-treatment-target-cell cultures.L'invention concerne une méthode de détermination de l'effet d'un traitement sélectionné administré à un patient, comprenant les procédures d'acquisition de données d'émission de COV de cultures de cellules cibles de pré-traitement et la production d'un profil de COV de cellules cibles de pré-traitement à partir de l'émission de COV des cultures de cellules cibles de pré-traitement ； la production d'un profil de COV de cellules cibles MCD par : (A) l'induction de MCD sur des cultures de c
