What is Iridium 192 used for?

Afterloading

This is the most effective and at the same time gentlest treatment for advanced or aggressive prostate cancer Afterloading represent.
In this form of brachytherapy, a high-dose radiation source is briefly inserted into the prostate. The proven treatment method is based on a remote-controlled one "Reloading (= afterloading)" the iridium radiation source in puncture needles inserted through the perineum. The spotlight is focused for a certain time at precisely calculated positions. In this way an optimal dose distribution is achieved.

Depending on the findings, this treatment is carried out 3 to 4 times under a short anesthetic at an interval of about 1 week.


Internal and external radiation - an effective combination

The most effective and sensible treatment for advanced or aggressive prostate cancer is this HDR afterloading combined with external radiation. The advantage of HDR afterloading therapy Compared to the sole external irradiation is that the targeted irradiation of the prostate can achieve a maximum dose increase with a simultaneous reduction of the radiation dose on the surrounding risk organs, especially on the rectum and urinary bladder. This greatly reduces complications and stress for the patient.

The combined afterloading therapy is particularly effective for locally advanced prostate carcinomas without distant metastases, as it includes a large safety area around the prostate and at the same time also includes the neighboring lymph nodes. Due to this large safety area, it is clearly superior to the operation.

Who is afterloading suitable for?

Suitable patients for afterloading therapy in combination with external radiation are risk patients with locally advanced prostate cancer without distant metastases in bones and lymph nodes (T2b and / or PSA> 10 and / or Gleason score> 7). The technique is currently being investigated in studies in patients with a low risk (T1b-T2a, PSA <10, Gleason score <7). As numerous studies confirm, the cure rate of combination therapy with little change in quality of life is clearly superior to surgical removal of the prostate. A current study by the West German Prostate Center showed that combined radiation therapy in patients with advanced prostate cancer leads to an excellent cure rate and at the same time does not impair the quality of life of the patients. In addition, there are significantly lower incontinence (<1-3%) and impotence rates (20-40%) than after surgical removal of the prostate. Another plus point: The patients are able to resume professional and private activities after just a few days. In the HDR brachytherapy it is a small, gentle procedure that is usually carried out on a short-term inpatient basis and only poses a low burden for the patient.


Course of therapy

Before afterloading therapy

After the urologist and radiotherapist have indicated the afterloading therapy, the "preliminary planning" is carried out using transrectal ultrasound over the rectum before the procedure. The resulting images are transmitted to a planning computer. Based on the size, shape and position of the prostate, the radiation therapist calculates the feasibility of the afterloading therapy
Blood-thinning medication such as aspirin, ASA, Eliquis, Lixiana, Plavix, Xarelto, Marcumar or comparable preparations must be discontinued one week before the operation in consultation with the treating doctor. Two days before the procedure, an antibiotic and an alpha blocker are taken according to the doctor's prescription. The day before the procedure, foods that are difficult to digest should be avoided. You are not allowed to eat or drink six hours before the procedure. The evening before the procedure, laxative measures are taken to empty the rectum.

The intervention during afterloading

Under a brief anesthetic, the urologist inserts special hollow needles sterile through the perineum to the calculated positions in the prostate under ultrasound control. The previously inserted urinary catheter is used to precisely identify the urethra in order to protect it as best as possible during the subsequent planning of the dose distribution. In the next step, ultrasound slice images are made for the treatment planning. With the help of a special computer program, a 3D model of the prostate is created and the radiation therapist calculates the dose distribution and the required loading of the individual hollow needles with the Iridium-192 source. The tiny radiation source can move to any position of the needle in millimeter steps and emit its radiation at the calculated stopping points over a defined period of time. A total of up to 200 possible stopping points of the radiation source are defined.
After the treatment plan and dose distribution have been completed, all needles are connected to the Afterloading device connected by means of thin extension hoses. Only then does the actual irradiation take place, i.e. the radiation source now moves needle by needle and irradiates the tumor on site. The needles are firmly fixed in the prostate so that the target and risk organs do not change in their position and distance from one another. The pure irradiation time lasts only a few minutes and the patient is in a special radiation protection bunker during this time. As with the seed implantation, urologists and radiation therapists can follow the treatment in real time on the monitor using the latest computer technology. The smallest deviations of the implantation needles from the previously calculated radiation plan are immediately taken into account and optimized accordingly. After the prostate has been completely irradiated, the needles and catheter can be removed and the patient can wake up from the anesthesia. The procedure usually takes 45 to 60 minutes. There is usually a week break between treatments. The additional external radiation takes about 6 weeks. In total, the radiation is usually about 30 times up to a total dose of 50-55 Gy on five days per week.

After the afterloading therapy

The urological follow-up examinations such as the determination of the PSA value, an ultrasound examination and the recording of side effects using standardized questionnaires are initially carried out quarterly. Usually, patients can resume their professional activities within a few days after the procedure. In the initial period, those treated should take care of themselves and pay attention to the following: Bathing, swimming, sauna visits, sexual activities and heavy lifting should be avoided in the first two weeks. Pressure load on the prostate and perineum, e.g. B. cycling, riding or sitting on hard surfaces should be avoided for about four weeks.

Afterloading - side effects

The side effects of HDR afterloading are minor. Since the afterloading procedure is usually combined with external radiation, local irritation of the bladder and bowel can occur. After the external radiation, some patients also complain of fatigue. The side effects usually go away on their own after the treatment. Some people urinate more frequently immediately after the procedure. The cause of this is a slight temporary irritation from the insertion of the catheter.