External Radiotherapy for Prostate Cancer
What is External Radiotherapy?
External radiotherapy is a technique used to treat localised prostate cancer – i.e., that has spread outside the organ – or locally advanced cancers that only affect the area adjacent to the prostate.
In some cases, the therapy is also beneficial in controlling the cancer’s progression and relieving symptoms. It can also be used to treat cancer metastases (e.g., when located in the bone) if symptomatic or few in number.
Radiotherapy seeks to destroy cancerous cells without causing major damage to healthy tissue. It uses ionising radiation in the aim of permanently eliminating the cancer and preventing it from growing or spreading to other parts of the body.
Though healthy cells are affected, they have the power to recover their integrity and function more quickly.
What is the External Radiotherapy Treatment Procedure?
Prior to Radiotherapy
Prior to the procedure, the specialist creates a treatment plan that is shared with the patient.
At this stage, you should ask any questions you might have. It is very important for patients to understand and be prepared for the therapy and how to deal with it.
A few days before external radiotherapy, a radiation “simulation” (for planning) is performed.
In some cases, some seeds-markers may be inserted into the prostate by the radiologist.
During the procedure, it is very important that you lie still.
To define the treatment schedule, various CT scan plans are produced to determine the exact area of the body to be treated.
This allows the radiology team to know the exact position, size and form of each patient’s prostate, accurately determining a suitable dosage for the cancer’s characteristics. The aim is to ensure the areas surrounding the affected organ are subject to the least radiation possible.
With regard to dietary issues, the state of the bladder or the need for an intestinal cleanse prior to radiotherapy, the doctor or technician performing the treatment will provide you with all the advice you need to be ready for the session.
During and After Radiotherapy
The hard procedure lasts around 30 minutes with part of the time reserved for preparation. The patient is lying down during the session and does not feel any pain or discomfort.
External radiotherapy is performed using a device called a linear accelerator that emits powerful beams of radiation. During the treatment, the machine revolves around the patient as it emits pre-defined and pre-programmed amounts of radiation at various angles.
The radiology team is in an adjacent room and communicates with the patient via audio or video throughout the session.
Generally, the patient undergoes a daily session 5 days a week. After each session, the patient returns home. The average plan lasts 6–7 weeks but varies depending on the case, type and characteristics of the cancer.
After radiotherapy treatment, there are natural follow-up consultations. These allow the doctor to monitor the progress and effectiveness of the treatment. It is normal to do tests and analyses like checking PSA levels.
The consultations also represent an opportunity for doctors to help patients manage the treatment’s side effects.
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What is the Post-Treatment Like?
In general, patients are followed after treatment and have consultations with urologists and radiotherapists at variable intervals.
Normally, the first observation is held 1–3 months after the treatment. This assessment includes tests to monitor the evolution or to detect if significant side effects have occurred.
Side Effects of External Radiotherapy
Radiotherapy can cause side effects that must be followed after treatment. The side effects can be immediate (during or right after treatment) or delayed (months or years later).
Initially, the most common of these are:
- Intestinal problems (such as diarrhoea and blood in the stool caused by proctitis);
- Urinary symptoms like a burning sensation when urinating, sudden urge to urinate, urinating more often or even urinary incontinence (radiotherapy can cause inflammatory changes in the bladder and urethra);
- Fatigue (may last up to a few weeks or months after treatment).
In the long term, another type of symptom may occur:
- Erectile dysfunction (“sexual impotence”), which may occur months or years after treatment;
- Ejaculatory disorders;
- Urinary problems caused by urethral strictures ("narrowing");
- Cystitis symptoms (bladder "inflammation"). These can be mild and similar to a urinary infection, causing burning during urination and more frequent urination. Sometimes, blood occurs in the urine caused by this radical cystisis that may be very hard to control. It may involve hyperbaric oxygen chamber treatment, bladder embolization or even surgery to remove the bladder.
Dr. José Santos Dias
Clinical Director of the Instituto da Próstata
- Bacherlor's Degree from the Faculty of Medicine at the University of Lisbon
- Specialist in Urology
- Fellow of the European Board of Urology
- Autor dos livros "Tudo o que sempre quis saber Sobre Próstata", "Urologia fundamental na Prática Clínica", "Urologia em 10 minutos","Casos Clínicos de Urologia" e "Protocolos de Urgência em Urologia"
FAQs about External Radiotherapy
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- DIAS, José Santos. Urologia Fundamental: na prática clínica. Lisboa: Lidel - Edições Técnicas, Lda, 2010.
- DIAS, José Santos. Tudo o que sempre quis saber sobre a Próstata. Lisboa: Lidel - Edições Técnicas, Lda, 2014.
- External beam radiation for prostate cancer - https://www.mayoclinic.org/tests-procedures/external-beam-radiation-for-prostate-cancer/about/pac-20384743
- Radiation Therapy for Prostate Cancer - https://www.hopkinsmedicine.org/health/conditions-and-diseases/prostate-cancer/radiation-therapy-for-prostate-cancer
- What is external beam radiation therapy for prostate cancer?
- Getting External Beam Radiation Therapy - https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/radiation/external-beam-radiation-therapy.html