Intracavitary therapy (synonym: intracavitary brachytherapy) is a variant of brachytherapy from the field of radiation medicine, which is primarily used as a therapeutic measure in oncological gynecology and ear, nose, and throat medicine. The main field of application of intracavitary therapy is the treatment of tumors. Intracavitary therapy enables a high local radiation dose to be applied in the area of the tumor, while at the same time sparing radiation-sensitive organs such as the bladder and rectum (rectum).
Indications (areas of application)
Gynecology
- Cervical carcinoma (cervical cancer) – cervical carcinoma is a malignant tumor, which is currently the second most common malignant neoplasm in women. In the case of cervical carcinoma, there is a possibility of intracavitary therapy through the use of a so-called cervical sleeve. For this purpose, the patient is put under anesthesia only for the first application. The applied cervical sheaths, through which the calculated radiation dose is delivered, can remain for the entire treatment period. Thus, further anesthesia can be avoided during this form of intracavitary therapy. In addition, this principle allows a reduction in the amount of the individual dose. Another positive consequence is an increase in the therapeutic width.
- Endometrial carcinoma (uterine cancer) – endometrial carcinoma can be treated by intracavitary brachytherapy. Currently, however, there is a tendency towards percutaneous irradiation, where a more homogeneous dose distribution can be achieved while sparing the organs at risk.
Otolaryngology
- Naso- and hypopharyngeal carcinoma (cancer of the nose and pharynx) – in these tumors from the field of otorhinolaryngology, intracavitary therapy is used as a very successful method for the treatment of naso- and hypopharyngeal carcinoma as part of a curative treatment option.
Visceral Oncology
- Esophageal carcinoma (esophageal cancer) – the indication for treatment of esophageal carcinoma is particularly when the tumor to be treated does not exceed a depth of 1 cm.
- Tracheal and bronchial carcinoma (tracheal and lung cancer) – intracavitary brachytherapy is a palliative treatment option for tracheal and bronchial tumors. Encouraging results show this treatment strategy, among other things, in the short-term therapy of endoluminal tumors.
- Anal carcinoma (anal cancer) – as an advantage of brachytherapy in the treatment of anal carcinoma must be mentioned the usually achievable preservation of sphincter function (sphincter function) with higher local tumor control rates. Studies also show partially improved cure rates with the use of the procedure. Thus, a heavy-duty abdominoperineal rectal extirpation (complete rectal removal) is usually necessary exclusively in the case of non-response to radiotherapy or the occurrence of a recurrence (recurrence of the disease).
Urology
- Urinary bladder carcinoma (urinary bladder cancer) – urinary bladder carcinoma can also be treated by intracavitary brachytherapy; in recent studies, cytostatic drug combinations sometimes show better results in borderline surgical cases, both pre- and postoperatively.
Contraindications
Contraindications vary depending on the tumors being treated.
Before therapy
Before intracavitary therapy can be used as a treatment modality, grading (assessment of tumor differentiation) and staging (involvement of other organ systems) must first be performed by an experienced pathologist. Other treatment options, such as the use of targeted chemotherapy, must be reviewed. Furthermore, a detailed review of the indication must be performed.
The procedure
The radiation source used in intracavitary brachytherapy is usually 192 iridium gamma emitter. Depending on the localization, the applicators (radiation carriers) are adapted to the respective target area in the body cavity to be irradiated, both in terms of shape and volume. The applicators shaped in this way are first positioned in accordance with the afterloading principle (reloading procedure) and then remotely loaded with the radioactive source.
After therapy
Following intracavitary brachytherapy, depending on the type of tumors, various examinations are necessary in a defined period of time to monitor tumor growth or tumor remission. Furthermore, the occurrence of complication must be monitored and treated if necessary.
Possible complications
- Secondary tumors (second tumors) – as a result of brachytherapy, secondary tumors may develop because not only tumor cells but also healthy body cells are damaged.
- Osteoradionecrosis (abbreviation ORN; is a special form of radiation necrosis, which is counted among the aseptic bone necroses) – especially in the treatment of naso- and hypopharyngeal tumors, osteoradionecrosis can be cited as a special possible complication.
- Mucositides (mucosal damage) – depending on the location of the target tissue, the risk of mucosal damage is significantly increased. Inflammatory reactions can affect almost any organ exposed to radiation.
- General blood count changes – leukopenias (reduction in the number of white blood cells) and thrombocytopenias (reduced number of platelets in the blood compared to the norm) often occur during therapy. Other consequences of this include an increased risk of infection and bleeding.
