A photodynamic treatment system comprising - an interventional device comprising a bundle of a plurality of optical fibers (F1, F2, F3) with distributed fibers ends forming respective light exit ports configured to emit light in different directions, wherein the bundle comprises an optical shape sensing fiber configured to sense the position and orientation of the fiber ends, - an optical console configured to be connected to the plurality of optical fibers (F1, F2, F3), and configured to generate individually controllable light outputs (LD1, LD2, LD3) to each of the plurality of optical fibers in response to a light dose signal, - a position console configuared to be connected to the optical shape sensing fiber and configured to determine the actual position and actual orientation of the fiber ends (P_O) of the interventional device, based on an optical measurement applied to the optical shape sensing fiber, and - a processor including a control algorithm (CTLA) configured to generate the light dose signal which controls the optical console to generate individual light intensity values as light outputs (LD1, LD2, LD3) to each of the plurality of optical fibers (F1, F2, F3) accordingly, wherein the control algorithm (CTLA) generates the light dose signal in response to: - the determined actual position and actual orientation of the fiber ends (P_O) from the position console, and - three-dimensional body anatomy image information obtained by a first image modality which is configured to discriminate between different anatomical tissues inside a body. - an interventional device comprising a bundle of a plurality of optical fibers (F1, F2, F3) with distributed fibers ends forming respective light exit ports configured to emit light in different directions, wherein the bundle comprises an optical shape sensing fiber configured to sense the position and orientation of the fiber ends, - an optical console configured to be connected to the plurality of optical fibers (F1, F2, F3), and configured to generate individually controllable light outputs (LD1, LD2, LD3) to each of the plurality of optical fibers in response to a light dose signal, - a position console configuared to be connected to the optical shape sensing fiber and configured to determine the actual position and actual orientation of the fiber ends (P_O) of the interventional device, based on an optical measurement applied to the optical shape sensing fiber, and - a processor including a control algorithm (CTLA) configured to generate the light dose signal which controls the optical console to generate individual light intensity values as light outputs (LD1, LD2, LD3) to each of the plurality of optical fibers (F1, F2, F3) accordingly, wherein the control algorithm (CTLA) generates the light dose signal in response to: - the determined actual position and actual orientation of the fiber ends (P_O) from the position console, and - three-dimensional body anatomy image information obtained by a first image modality which is configured to discriminate between different anatomical tissues inside a body. - the determined actual position and actual orientation of the fiber ends (P_O) from the position console, and - three-dimensional body anatomy image information obtained by a first image modality which is configured to discriminate between different anatomical tissues inside a body.