WO2007040392A2

WO2007040392A2 - Rectal balloon probe for protecting the rectal wall during radiotherapy

Info

Publication number: WO2007040392A2
Application number: PCT/NL2006/000500
Authority: WO
Inventors: Emmanuel Nicolaas J.T. Van Lin; Eric Arjen Winkel
Original assignee: Van Lin Emmanuel Nicolaas J T; Eric Arjen Winkel
Priority date: 2005-10-04
Filing date: 2006-10-04
Publication date: 2007-04-12
Also published as: WO2007040392A3

Abstract

Probe, for example for protection of the rectal and anal wall tissues during radiotherapy, for example an insertable intracavity probe, for example to be used during radiotherapy of a prostate gland, wherein the probe at least includes a shaft having a closed distal tip, wherein the shaft is provided with an inflatable device, for example a balloon and/or a elastic membrane, wherein the inflatable device substantially abuts an outer surface of the shaft when the inflatable device is in a deflated position. The invention also provides a system for planning and delivering radiation therapy treatment of an internal organ of a patient by a radiation emitting device, comprising a radiation emitting device; and a probe according to the invention to be inserted within a cavity of a patient during delivery of a dose from the radiation emitting device.

Description

Probe, system and use of a probe

FIELD OF THE INVENTION

The present invention relates to a probe, a system and a use of a probe.

BACKGROUND OF THE INVENTION

Radiation treatment of pelvic cancers, such as prostate and gynecological cancers, is often difficult due to the proximity of radiation sensitive tissues. The rectal wall and the anal complex are very sensitive to irradiation. Often seen radiotherapy complications are radiation proctitis (rectal bleeding) and faecal leakage and faecal incontinence.

The amount of rectal and anal tissue irradiated to intermediate and high radiation doses determines the severity of the mentioned complaints. It is known that higher radiation doses improve the outcome of different types of cancer, such as prostate cancer. But higher doses lead to more rectal and anal complaints.

An inflatable rectal probe is capable to push parts of the rectal and anal tissue away from the high dose regions, leading to decreased rectal and anal toxicity, as will be described in a non-prepublished article by van Lin, et al in the radiotherapy journal " Int J Radiat Oncol Biol Phys" in 2005, entitled "Rectal wall sparing effect of three different endorectal balloons in 3D conformal and IMRT prostate radiotherapy". This study, comparing three known rectal probes, will conclude that a rectal probe is capable of reducing the amount of rectal and anal wall exposed to intermediate- and high irradiation doses, during pelvic radiotherapy, which may lead to reduced rectal and anal toxicity. The combination of a rectal probe and a standard world-wide used irradiation technique (3D conformal radiotherapy), may lead to reduction of the expected toxicity equal to the level as can be achieved by applying a more complex technique, the so-called intensity-modulated radiation therapy (IMRT). One of the studied probes, known from the prior art, is described in WO 03/013643.

SUMMARY OP THE INVENTION

The present invention aims to provide an improved probe. In an aspect of the invention, there is provided a probe, for example for protection of the rectal and anal wall tissues during radiotherapy, for example an insertable intracavity probe, for example to be used during radiotherapy of a prostate gland, wherein the probe at least includes a shaft having a closed distal tip, wherein the shaft is provided with ah inflatable device, for example a balloon and/or a elastic membrane, wherein the inflatable device substantially abuts an outer surface of the shaft when the inflatable device is in a deflated position.

In an aspect of the invention, there is provided a probe, wherein the probe at least includes a shaft having a closed distal tip, wherein the shaft is provided with an inflatable device, for example a balloon and/or a elastic membrane, wherein the inflatable device is substantially cylindrical when the inflatable device is in a deflated position.

In an aspect of the invention, there is provided a probe, wherein the probe at least includes a shaft having a closed distal tip, wherein the shaft is provided with an inflatable device, for example a balloon and/or a elastic membrane, wherein the inflatable device is substantially an ellipsoid and/or substantially spherical when the inflatable device is in an inflated position.

In an aspect of the invention, there is provided a probe, for example a probe according to an above-mentioned embodiment, including a shaft having a closed distal end, wherein the shaft is provided with an inflatable device which is be configured to be spring-biased against the shaft with an inherent spring force or elastic force of the inflatable device when the inflatable device is in a deflated position, for example such that the internal spring force or elastic force of the inflatable device can hold that device tightly on the shaft. In an aspect of the invention, there is provided a probe, for example for protection of the rectal and anal wall tissues during radiotherapy, for example an insertable intracavity probe, for example to be used during radiotherapy of the prostate gland, wherein the probe at least includes a shaft, wherein the shaft is provided with an inflatable device, for example a balloon or a membrane, wherein the probe is provided with at least one material or substance having a high density, such that said material can be detected during radiotherapy.

In an aspect of the invention, there is provided a system for planning and delivering radiation therapy treatment to an internal organ of a patient by a radiation emitting device, comprising a radiation emitting device, and a probe according to the invention, to be inserted within a cavity of a patient during delivery of a dose from the radiation emitting device

In an aspect of the invention, there is provided a use of a probe according to the invention during delivery of a dose from a radiation emitting device, wherein —for example- the probe is being inserted in a cavity of a patient, wherein subsequently a nearby organ and/or tissue is being irradiated.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

- Figure 1 depicts a side view of an embodiment of the invention, wherein the inflatable device is in a deflated position; - Figure 2 depicts a side view of an embodiment of the invention, wherein the inflatable device is in an inflated position;

- Figure 3 depicts a cross-section over line IH-III of Fig. 1;

- Figure 4 depicts a cross-section over line IV-IV of Fig. 1 - Figure 5 depicts a perspective side view of an embodiment comprising an advantageous stopper embodiment;

- Figure 6 depicts another perspective side view of the embodiment of Fig. 5;

- Figure 7 depicts a side view of a first part of the stopper of the embodiment of Fig. 5;

-Figure 8 is a top view of the stopper part shown in Fig 7; and -Figures 9A, 9B and 9C are a side view, top view and bottom view, respectively, of a second stopper part of the embodiment of Fig. 5.

DETAILED DESCRIPTION

Figures 1-4 schematically depict an embodiment of the invention. The embodiment is provided with a probe, for example for protection of the rectal and anal wall tissues during radiotherapy, for example an insertable intracavity probe, for example to be used during radiotherapy of a prostate gland, uterus, bladder, or during any other pelvic irradiation. Figures 5-6 depict a further embodiment, comprising an advantageous stopper assembly 9.

The probe includes a main hollow shaft 1 having a closed distal tip T. The shaft 1 can be arranged in various ways. In the present embodiment, the shaft 1 is substantially cylindrical. In the embodiment, said tip T is a substantially rounded tip T. Preferably, said shaft is a flexible shaft 1. The shaft can be made of various materials, for example one or more plastics or other materials. In one embodiment, the shaft 1 comprises PVC (p oly vinychloride) . The main shaft 1 can have various dimensions. For example, a diameter of the shaft 1, measured in a transversal cross-section, can be larger than about 5 mm, for example about 9 or 10 mm, or a different diameter. A length of the shaft 1 can be, for example, at least 5 cm, for example about 10 cm or more. Also, the shaft 1 can have different dimensions.

In the present embodiment, a second proximal end of the main shaft 1 has been extended by a second hollow shaft 3. This second shaft 3 can also have various dimensions, and can be made of various materials. For example, one of the shafts 1,3 (such as the second shaft 3) can be made of transparent material and the other (for example the main shaft) of non-transparent material.

Besides, in an embodiment, the probe can be provided with a positioning scale 11 on an outer surface thereof.

The main shaft 1 is provided with an inflatable device (or member) 2. The inflatable device 2 can be made of various materials. For example, the inflatable device can include a balloon, a elastic membrane and/or an other suitable inflatable device 2. Preferably, the inflatable device 2 is made of one or more relatively thin layers or sheets. For example, the inflatable device 2 can be made of a suitable Silicone. It can be a silicone balloon 2, or a balloon made of a different suitable material, for example a suitable elastic material. Besides, for example, the inflatable device 2 can be configured to deflate to its deflated position under the influence of an inherent spring force or elastic force of the inflatable device 2. The inflatable device 2 can be a substantially cylindrical sheet, or tube having a relatively thin tube wall, of an elastic material, which fits tightly onto the outer surface of the main shaft 1.

As is shown, said inflatable device 2 can provide at least part of the outer surface if the probe. During use, for example, an outer surface of said inflatable device 2 can be brought into contact with rectal and anal wall tissues during use of the probe. In the present embodiment, the inflatable device 2 is spaced-apart, over a relatively short distance, from the distal tip T of the probe This can be advantageous with respect to a manufacturing point of view. Also, a distal part 2D of the inflatable device is spaced-apart from the distal end of the shaft when the inflatable device is in an inflated position (see Figures 2 and 4). Alternatively, the inflatable device can extend over the tip T.

In the present embodiment, both a distal part 2D as a proximal part 2P of the inflatable device 2 are connected to the outer surface of the main shaft 1. The connection can be provided in various ways, for example by a suitable adhesive connection or a different type of bonding. The connections between the inflatable device 2 and the shaft 1 are preferably substantially gastight-connections. For example, both a proximal part 2P and a distal part 2D of the inflatable device 2 can include ring shaped connection parts 2P, 2D, between which a remaining part 2A of the inflatable device 2 extends. Said ring shaped connection parts 2P, 2D can fit tightly onto the main shaft 1, and hold a remaining part 2A of the inflatable device 2 in a desired position, such as is shown in Fig. 1.

Said inflatable device 2 can have various dimensions. For example, the distance between a proximal end and distal end of the inflatable device 2, measured parallel to the main shaft 1, can be about 3 cm or more. As an example, said distance between a proximal end and distal end of the inflatable device 2 can be in the range of about 2.5-10 cm, for example 4-10 cm, for example in the range of about 4.5-7.5 cm, or a different range.

Besides, the probe can further comprise an inflating device, or be connected or connectable thereto. For example, one or both of the probe shafts can be connected to an inflating device. In the present embodiment, part of said main shaft 1 extending along said inflatable device includes a number of apertures 7, for example to inflate and deflate the inflatable device using a suitable fluid. The fluid can include, for example, one or more gasses, one or more liquids, air, or a different fluid. During use, for example, gas and/or liquid can be supplied through the shafts 1,3 and the apertures 7 to the inflatable device 2 for inflation of that device. Such supply of gas and/or liquid is shown by arrows G in Fig. 4. As is shown in figures 1 and 2, for example, the probe can be provided with a suitable supply line 4 to supply gas and/or air to the probe. Such a supply line 4 can be arranged in various ways, and can include for example a flexible supply tube 4. In the present embodiment, the supply line 4 is provided with a closing device, for example a suitable pinch clamp 5, for closing the supply line after the inflatable device 1 has been inflated. Also, a proximal end of the supply line 4 can include a suitable coupling part 6, for example of a standardised construction as in the Luer standard, to connect the supply line to a gas and/or liquid source (not depicted). As an example, the coupling part 6 can include a Female luer lock part.

The probe can also include a stopper (part 9), for example a foam and/or plastic stopper. The stopper can include a suitable ring, clamp, paperclip, plastic device or a different type of stopper. For example, the stopper 9 can be used in combination with a distance or positioning scale 11 and/or markers 8 (see below).

An advantageous embodiment of a detachable stopper assembly 9 is depicted in Figures 5-9. The stopper 9 can comprise a first disc shaped stopper part 9A that can be clamped onto the main shaft 1 using a second stopper part 9B. The disc shaped part 9A comprises a central opening (through-hole) 14 to receive the second part 9B. As is depicted in Figures 9A-9C, the second stopper part is a clamping member 9B that encloses an opening (through-hole) 15 to receive the main shaft 1. Preferably, this opening 15 has about the same diameter as or is slightly larger than an outer diameter of the main shaft 1, such that the clamping member 9B can be slid onto that shaft 1 with little radial clearance.

An outer contour of the clamping member 9B is slightly tapered/conical (see Fig. 9A), wherein the diameter D2 of a first end of that member 9B is slightly smaller than the diameter D 3 of the opposite end. Besides, the wider axial end of the clamping member 9B comprises radially outwardly protruding edge parts 16. Also, the clamping member 9B comprises a longitudinal slit 17 and a longitudinal groove 18 extending opposite each other. The longitudinal groove 18 'divides' the clamping member 9B into two halves that can pivot with respect to each other about a hinge part 19, such that the diameter of the shaft receiving opening 15 can be altered.

During use, the clamping member 9B can be positioned onto the shaft by sliding the clamping member 9B onto the shaft, such that the shaft reaches through the clamping member 9B. Then, the disc part 9A can be slid onto the clamping member 9B in a mounting direction M (see Fig. 6), from the first end towards the wider part and protruding edge parts 16 of the clamping member 9B, to cooperate with the clamping member 9B to provide a desired clamping onto the shaft 1. The configuration of the clamping member 9B and disc part 9A is such that during this mounting of the disc shaped member 9A onto the clamping member 9B, the disc shaped member 9A presses the clamping member 9B inwardly and the diameter of the centre opening 15 of the clamping member 9B is reduced, so that the clamping member 9B is being clamped onto the shaft, wherein the disc part 9A is being clamped onto the clamping member 9B at the same time. Thus, after mounting (see Fig. 5-6), the disc shaped member 9A clamps itself onto the clamping member 9B, and forces the clamping member 9B towards the shaft 1 at the same time. After use, the stopper 9A, 9B can simply be removed by carrying out these steps in reverse order. The stopper 9 can be used in combination with the present probe, or with other probe types. Besides, disc shaped parts 9A of various dimensions, particularly outer diameters, can be used in combination with the clamping member 9B. Also, the disc shaped part 9A can be substantially rigid having an centre hole 14 of fixed diameter Dl. In that case, preferably, the diameter Dl of the central opening 15 of the disc shaped part 9A is about the same diameter as or is slightly larger than the diameter D2 of the first end of the clamping member 9B, such that the disc shaped part 9A can he slid onto the first end of the clamping member 9B with little radial clearance. Alternatively, the disc shaped part 9A can be resilient or adjustable, for example in the case that the disc is provided with a radial slit 20 (schematically indicated by dashed lines in Fig. 8), to slightly adjust the diameter of the centre hole 14 when mounting the disc shaped part 9A onto the clamping member 9B.

Again referring to Figures 1-4, in the present probe embodiment, the inflatable device 2 can substantially abut an outer surface of the main shaft 1 when the inflatable device is in a deflated position (see figures 1 and 3). Also, as is clearly depicted, the inflatable device 2, or at least its outer surface, can be substantially cylindrical when the inflatable device 2 is in its deflated position. Also, as is shown in figures 2 and 4, in an embodiment, the inflatable device 2 can be substantially an ellipsoid and/or substantially spherical when the inflatable device is in an inflated position, with the main shaft extending for example centrally through the inflatable device.. Also, the inflatable device can have other shapes when in the inflated position, for example rectangular, square shaped, saddle shaped and a combination of the mentioned shapes and/or other shapes.

For example, the inflatable device 2 can be configured to be spring- biased with an inherent spring force or elastic force of the inflatable device 2, when the inflatable device is in its deflated position on the main shaft 1. Such an internal spring force or elastic force of the inflatable device 2 can hold that device 2 tightly on the main shaft 1. For example, an inner surface of the inflatable device 2 can abut an outer surface of the shaft 1 substantially uninterruptedly, expect for the areas where the shaft 1 includes said apertures 7..

In an embodiment, the probe is provided with at least one material or substance 8 having a high density, such that said material can be detected during radiotherapy. For example, said at least one material or substance 8 can include one or more metals. For example, said at least one material or substance having a high density can include gold or tungsten. Besides, said at least one material or substance having a high density can include lead, or a different material. In the present embodiment, said at least one material or substance 8 having a high density is located in a fixed position with respect to part of said inflatable device 2. For example, the at least one material or substance 8 having a high density is located at or near a proximal part 2P of said inflatable device 2 (see the figures), or at or near a distal end of the probe, or at a different location Said material 8 can be integrated, for example, in the main shaft 1 of the probe, of be provided in a different way. Besides, the probe can include grains or small parts of said high density material 8.

An aspect of the invention provides a system for planning and delivering radiation therapy treatment to an internal organ of a patient by a radiation emitting device, comprising a radiation emitting device; and a probe, for example a probe as is shown in figures 1-6. The probe is to be inserted within a cavity of a patient during delivery of a dose from the radiation emitting device The inflating device can comprise a syringe, for example to supply gas or liquid to the supply line 4 of the probe.

As an example, the probe can be used during delivery of a dose from a radiation emitting device, wherein —for example- the probe is being inserted in a cavity of a patient, wherein subsequently a nearby organ and/or tissue is being irradiated. For example, the inflatable device 2 can be inflated to protect rectal and anal wall tissues during radiotherapy. Also, one or more probe parts 8 having substantially high densities, if available, can be detected for positioning the inflatable device 2 or probe with respect to a patient or part of the patient. In an aspect, wherein the internal organ can comprise a prostate gland.

In an aspect, the present invention can relate to an insertable probe system and method of use therefore designed to protect the rectal and anal tissues during radiation therapy of pelvic cancers, such as prostate and cervical cancer. Although we have tested a probe for specific treatment of the prostate, it should be understood that this probe, use, method and system as described here can be applicable to various types of pelvic radiotherapy treatments, where the rectal and anal tissues are at risk for obtained radiation induced toxicity. The probe of the present invention can be designed for single use and the second shaft 3 can be used as a handle, preventing any contact between the technician and human body fluids and rectal contents.

In an embodiment, the probe can comprise a shaft, which supports an inflatable balloon (or inflatable device 2) at its distal end. This probe can be designed for insertion into the body through the anal canal and positioned in the distal end of the rectal cavity. Inflation of the inflatable device 2 can result in dilation of the rectal wall. Insertion of the probe also can dilate the anal canal, pushing the dorsal parts of the anal canal and pelvic muscles away from the apical part of the prostate. The shaft of the probe can be flexible and hollow, facilitating an easy and comfortable insertion of the probe. The tip of the shaft can be rounded and relatively broad, preventing any punctuation or damage of the pelvic tissues during introduction.

In deflated situation the balloon (or inflatable device 2) can encompass the main probe shaft 1 closely, so that insertion and extraction is easy. To inflate the inflatable device 2 a syringe can be connected to the shaft and a volume-limited amount of air, or a different fluid, can be delivered through the shaft by a separate connector tube into the inflatable device 2 . A stop cock can be provided to maintain the air within the inflatable device 2. After insertion of the probe, an anti- migration clamp or stopper 9 can be fixed to the shaft (for example by clamping, as in Fig. 5-6 using the stopper assembly according to Figures 7-9). A distance scale 11 with distance marks can be provided on the outer surface of the shaft. For every patient an individually chosen, depending on the patients' anatomy, position of the ant- migration clamp or stopper 9 (see above) can be noted. During treatment preparation and the daily-executed treatment the same clamp or stopper position can be used to prevent migration of the probe. This prevents any unwanted position variation from day to day and during the daily radiotherapy treatment session. During the irradiation treatment, images of the pelvic area can be made to verify the patient, the prostate and probe position (so-called portal images). The bony structures are well visible on these images. To visualize the position of the prostate, gold markers can be inserted into the prostate, as part of the pre-treatment patient preparation phase, as described in the article by van Lin et al., in the radiotherapy journal " Int J Radiat Oncol Biol Phys" in 2005, entitled "The effect of an endorectal balloon and off-line correction on the interfraction systematic and random prostate position variations: A comparative study." In this prevent invention; high-density material (e.g. gold, lead, tungsten) markers 8 can be inlayed into the exterior surface of the probe shaft 1. This enables to verify the day-to-day position of the probe, and enables to perform a correction procedure to correct any observed misplacements of the probe.

The present invention can relate generally to a system and method for performing therapeutic treatments of disease. The present invention can relate to an insertable probe system and method of use therefore designed to protect the rectal and anal tissues during radiation therapy of pelvic cancers, such as prostate and cervical cancer.

The present probe can provide a user- and patient-friendly rectal probe, which can warrant increasing its acceptability. In terms of hygienic conditions, the probe according to the invention can be advantageous. In general a radiation treatment can consist of 30 — 40 daily treatments sessions, 5 days a week. This means that a rectal probe has to be inserted 30 — 40 times in each patient. Patient and technician (people who insert this device on a daily basis) safety and comfort are main factors in the use of these devices. The present probe does not have to rely on the use of condoms, such as is prescribed when using open-air prior art rectal probes which have a direct connection between the rectal lumen and the outer air. Besides, the present prove experiences relatively little extraction of rectal content, when extracting the probe out of the patient through the anal canal during use.

Also, the present probe can cause relatively little or substantially no irritation of the anal and rectal tissues (bleeding and pain) and/or unwanted shifts of the pelvic organs, which might lead to incorrect (geographical miss) irradiation. With respect to prior art methods and systems, the present probe can provide an improved method and system for dilation of the rectal and anal wall to reduce the amount of rectal and anal wall exposed to intermediate- and high irradiation doses, during pelvic radiotherapy, which may lead to reduced rectal and anal toxicity. The present probe can provide a better method and system to reduce the hazards of contamination with human body fluids, during the process of daily insertion and extraction of a rectal probe.

The present probe can provide a better method and system to ensure repeated accurate placement of the rectal probe to prevent extra irritation of the anal and rectal tissues and to prevent unwanted shifts of the internal pelvic organs.

While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, the invention may take the form of a computer program containing one or more sequences of machine-readable instructions describing a method as disclosed above, or a data storage medium (e.g. semiconductor memory, magnetic or optical disk) having such a computer program stored therein.

The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.

Claims

1. Probe, for example for protection of the rectal and anal wall tissues during radiotherapy, for example an insertable intracavity probe, for example to be used during radiotherapy of a prostate gland, wherein the probe at least includes a shaft having a closed distal tip, wherein the shaft is provided with an inflatable device, for example a balloon and/or a elastic membrane, wherein the inflatable device substantially abuts an outer surface of the shaft when the inflatable device is in a deflated position.

2. Probe according to claim 1, wherein the inflatable device is spaced- apart from the distal tip of the probe

3. Probe according to claim 1 or 2, wherein the inflatable device comprises a Silicone balloon.

4. Probe according to any of the preceding claims, wherein both a distal part as an proximal part of the inflatable device are connected to the outer surface of the shaft, for example by a suitable adhesive.

5. Probe according to any of the preceding claims, wherein said shaft is a flexible shaft.

6. Probe according to any of the preceding claims, wherein said shaft comprises PVC (polyvinychloride).

7. Probe according to any of the preceding claims, wherein a distal part of the inflatable device is spaced-apart from the distal end of the shaft when the inflatable device is in an inflated position.

8. Probe according to any of the preceding claims, wherein part of said shaft extending along said inflatable device includes a number of apertures, for example to inflate and deflate the inflatable device using a suitable fluid.

9. Probe according to any of the preceding claims, including a shaft having a closed distal end, wherein the shaft is provided with an inflatable device which is be configured to be spring-biased against the shaft with an inherent spring force or elastic force of the inflatable device when the inflatable device is in a deflated position, for example such that the internal spring force or elastic force of the inflatable device can hold that device tightly on the shaft.

10. Probe according to any of the preceding claims, wherein the probe at least includes a shaft having a closed distal tip, wherein the shaft is provided with an inflatable device, for example a balloon and/or a elastic membrane, wherein the inflatable device, or its outer surface, is substantially cylindrical when the inflatable device is in a deflated position.

11. Probe according to any of the preceding claims, wherein the probe at least includes a shaft having a closed distal tip, wherein the shaft is provided with an inflatable device, for example a balloon and/or a elastic membrane, wherein the inflatable device is substantially an ellipsoid and/or substantially spherical when the inflatable device is in an inflated position.

12. Probe, for example for protection of the rectal and anal wall tissues during radiotherapy, for example an insertable intracavity probe, for example to be used during radiotherapy of the prostate gland, wherein the probe at least includes a shaft, wherein the shaft is provided with an inflatable device, for example a balloon or a membrane, wherein the probe is provided with at least one material or substance having a high density, such that said material can be detected during radiotherapy.

13. Probe according to claim 12, wherein said at least one material or substance having a high density includes a metal.

14. Probe according to claim 12, wherein said at least one material or substance having a high density includes gold or tungsten.

15. Probe according to claim 12, wherein said at least one material or substance having a high density includes lead.

16. Probe according to any of claims 12-15, wherein said at least one material or substance having a high density is located in a fixed position with respect to part of said inflatable device.

17. Probe according to any of claims 12-16, wherein said at least one material or substance having a high density is located at or near a proximal end of said inflatable device, or at or near a distal end of the probe.

18. Probe according to any of the preceding claims, wherein said inflatable device provides at least part of an outer surface if the probe.

19. Probe according to any of the preceding claims, wherein an outer surface of said inflatable device can be brought into contact with rectal and anal wall tissues during use of the probe.

20. Probe according to any of the preceding claims, further comprising a inflating device connected or connectable to the shaft for inflating the inflatable device.

21. Probe according to any of the preceding claims, comprising a stopper (9) that can be detachably clamped onto the shaft, the stopper comprising a first stopper part (9A) and a second stopper part (9B), the first stopper part (9A) having an opening (14) to receive the second stopper part (9B), the second stopper part (9B) having an opening (15) to receive the probe shaft, the configuration being such that a mounting of the first stopper part (9A) onto the second stopper part (9B) leads to a diameter reduction of the second stopper part (9B).

22. A system for planning and delivering radiation therapy treatment of an internal organ of a patient by a radiation emitting device, comprising a radiation emitting device; and a probe according to any of the preceding claims to be inserted within a cavity of a patient during delivery of a dose from the radiation emitting device

23. The system of claim 22 wherein the inflating device comprises a syringe.

24. Use of a probe according to any of the claims 1-21 during delivery of a dose from a radiation emitting device, wherein —for example- the probe is being inserted in a cavity of a patient, wherein subsequently a nearby organ and/or tissue is being irradiated.

25. Use according to claim 24, wherein the inflatable device is being inflated to protect rectal and anal wall tissues during radiotherapy.

26. Use according to claim 24 or 25, wherein one or more probe parts having substantially high densities are being detected for positioning the inflatable device with respect to a patient or part of the patient.

27. Use according to any of claims 24-26 , wherein the internal organ comprises a prostate gland, a bladder or an uterus.