Medical instrument for high dose rate brachytherapy

1. A device for interventional brachytherapy, comprising:

an applicator device configured to be inserted into, or near a region of interest within a living body, the applicator device comprising an inner wall and an outer wall, the applicator device defining a lumen for receiving a radiation source; and

an optical sensor configured to generate an output signal indicative of whether or not the radiation source is at a predetermined position within the lumen, the optical sensor including an optical source for emitting an optical signal into the lumen and an optical receiver configured to receive the emitted optical signal from the lumen;

wherein the optical sensor is at least one of:

located between the inner wall and the outer wall of the applicator device; or

coupled to the inner wall while being located at least partially inside the lumen;

or

located fully inside the lumen;

wherein the optical source and the optical receiver are positioned relative to each other to either, while the radiation source is at the predetermined position by one of:

block the emitted optical signal from reaching the optical receiver; or

redirect the emitted optical signal to the optical receiver;

wherein the optical signal received by the optical receiver when the radiation source is at the predetermined position within the lumen differs from when the radiation source is not at the predetermined position within the lumen.

2. The device as claimed in claim 1 , further comprising:

first and second optical fibers for causing a light signal to be guided through the length of the applicator device, said first optical fiber being coupled to the optical source and said second optical fiber being coupled to the optical receiver.

3. The device as claimed in claim 2 , wherein a plurality of fiber Bragg gratings are dispersed along a length of each of the first and second optical fibers, the optical signal being reflected by the plurality of fiber Bragg gratings to derive a temperature and/or strain of the applicator device.

4. The device as claimed in claim 1 , further including a second optical sensor, wherein the optical sensor and the second optical sensor are arranged to generate the output signal to enable tracking of a movement of the radiation source in the lumen.

5. The system as claimed in claim 1 , further comprising:

a processing unit arranged to process the output signal to determine:

a) a temperature and/or shape of the applicator device, or

b) a change in the temperature and/or the shape of the applicator device resulting from the radiation source being (i) deployed into the lumen, and/or (ii) at the predetermined position, and (iii) retrieved out of the lumen.

6. A system for interventional brachytherapy, comprising:

an applicator device configured to be inserted into, or near a region of interest within a living body, the applicator device comprising an inner wall and an outer wall, wherein the applicator device defines a lumen for receiving a radiation source and a plurality of optical sensors, each optical sensor being configured to generate an output signal into the lumen, the output signal being indicative of whether or not the radiation source is at a predetermined position within the lumen;

each optical sensor including an optical source for emitting an optical signal into the lumen and an optical receiver configured to receive the emitted optical signal from the lumen;

wherein the optical sensor is at least one of:

located between the inner wall and the outer wall of the applicator device; or coupled to the inner wall while being located at least partially inside the lumen; or

located fully inside the lumen;

a plurality of optical receivers configured to receive the emitted output signal from the lumen, wherein the plurality of optical sensors and the plurality of optical receivers are positioned relative to each other while the radiation source is at the predetermined position to either: (i) block the emitted output signal blocked from reaching the plurality of optical receivers; or (ii) redirect the emitted output signal to the plurality of optical receivers; and

a detector configured to detect the output signal generated by each of the plurality of optical sensors.

7. The system as claimed in claim 6 , further comprising:

a tracking unit configured to track movement of the radiation source in the lumen, said tracking unit being arranged to track the radiation source in the lumen based on the detection of the output signal.

8. The system as claimed in claim 7 , further comprising:

a signal generator arranged to generate a generation signal to be communicated to the lumen, wherein the signal generator is arranged to generate one or more optical generation signals of a predefined wavelength or wavelength range and wherein the signal generator is arranged to generate said one or more optical generation signals simultaneously or successively.

9. The system as claimed in claim 6 , further comprising a user interface unit for representing the position of the radiation source in the lumen.

10. The system as claimed in claim 6 , further comprising:

an alarm generator unit configured to generate an alarm while the position and/or the movement of the radiation source in the lumen violates a predetermined limit based on the output signal.

11. A method for assessing a position of a radiation source at a predetermined position within a lumen of an applicator device, said method comprising:

wherein the applicator device comprises an inner wall and an outer wall, the applicator device defining the lumen for receiving the radiation source;

positioning the radiation source into the lumen of the applicator device inserted adjacent a region of interest in a living body,

generating, with one or more optical sensors of the applicator device, an output signal indicative of whether or not the radiation source is at the predetermined position within the lumen, each optical sensor including an optical source for emitting an optical signal into the lumen and an optical receiver configured to receive the emitted optical signal from the lumen; and

wherein the optical sensor is at least one of:

located between the inner wall and the outer wall of the applicator device; or

coupled to the inner wall while being located at least partially inside the lumen, or

located fully inside the lumen;

assessing on the basis of the output signal, whether or not the radiation source is at the predetermined position, wherein each optical sensor generates the output signal by one of:

blocking the emitted optical signal from reaching the optical receiver; or

redirecting the emitted optical signal to the optical receiver;

wherein the optical signal received by the optical receiver when the radiation source is at the predetermined position differs from when the radiation source is not at the predetermined position.

12. A non-transitory computer readable medium comprising instructions executable by a computer to carry out the steps of the method as defined in claim 11 .