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Table of Contents
Topic 11 - Team P - Meera Martin, Priya Gupta, Satish Kumar, Sandeep chatlaparthy
====== Radiotherapy of Prostate Cancer: treatment concepts and side effects
====== Table of content:-
•medical treatment options and challenges
The prostate is a gland located between bladed and penis. It produces fluid that is essential for the protection and nourishment of sperm. When cells in the prostate gland grow out of control, it becomes prostate cancer.
• Prostate is present just below the urinary bladder, and it surrounds the urethra.
• It is an accessory sexual gland.
• Prostate is surrounded by seminal vesicles.
• Vas deferens start from the testicles and end in the prostate.
• Prostate secretes a fluid called seminal fluid, which provides mobility for the sperm as well as lubrication during intercourse.
• Has five lobes
o Anterior Lobe o Posterior Lobe o Median Lobe o 2 Lateral lobes
• Rapid growth and multiplication of tumor cells in the prostate.
• Restricts the volume of the urinary bladder.
• Long duration of urine flow.
• Thin stream of urine.
• Urge to go urine often.
• Dripping of urine.
• Hesitancy of urine.
• Later stages- Cancer shall spread to other parts like bladder bone and all parts in the reach of cancer cells.
Types of prostate cancer:
• Small cell carcinomas
• Neuroendocrine tumors
• Transitional cell carcinomas
Symptoms of prostate cancer can be:
• Dull pain in the lower pelvic area.
• Frequent urinating.
• Trouble urinating, pain, burning, or weak urine flow.
• Blood in the urine (Hematuria)
• Painful ejaculation.
• Pain in the lower back, hips, or upper thighs.
• Loss of appetite.
• Loss of weight.
• Bone pain.
o Using cystoscopy by inserting via the urethra and examining cells.
o It can distinguish Prostate hypertrophy and cancer precisely.
o Can identify tumor partially but it should be followed by FNAC or Biopsy to confirm.
• Prostectomy: The surgery can be done and remove the enlarged cancer gland, provided that the cancer is small and yet to spread. It sounds the same as scar less surgery, but the procedure is different.
• Chemotherapy: This treatment is used to kill the cancer cells by giving a drug through injection or orally when cancer spreads outside the prostate gland.
In the Radiotherapy, the patient is being exposed to the radiation of either cesium isotope or iridium isotope on the damaged area. The objective is to destroy the cancer cells (rapidly multiplying cells) and cure it.
• Brachy Therapy: In the case of cancer, which is not accessible from outside, pellets of Caesium or Iridium isotope is inserted inside the body of the patents where the tumor is present and, it been treated by the natural emission of radiation of the radioactive isotope.
• Chemoradiation: The patient is subjected to get both chemo and Radiotherapy at the same time.
Disadvantages/Side-effects of radiotherapy:
• Patients face pain.
• Alopecia (Loss of Hair) – Due to damage of hair cells.
• Vomiting - Due to damage of Stomach tissue.
• Infertility – Due to damage of sex cells.
• Erectile dysfunction.
• Bone marrow depletion – Bone marrow also gets depleted since it is also rapidly multiplying cell and bone marrow is the one that produces RBC, WBS, and Platelets.
• Anemia – Due to the Depletion of RBC, resulting in Bone marrow depletion.
• Leukocytopenia – Due to depletion of WBC resulting in Bone marrow depletion.
• Thrombocytopenia – Due to depletion of Platelets resulting in Bone marrow depletion.
• Bone cancer.
• Pain in Bone
o Osteomalacia and Osteonecrosis where blood capillary of bone gets destroyed and blood flow to a bone is restricted resulting in softening of bone in the starting stage and finally resulting in the death of bone
• Urinary incontinence – urinary sphincter gets destroyed, so the inability to hold urine.
• Rectile bleeding.
• Reduced level of testosterone.
Medical treatment options and challenges:
Treatment of prostate cancer relies on a number of factors like the rate at which cancer grows, the overall health of the patient, its aggressiveness, and also the benefits and side effects of the treatment. There is a range of treatment options available for prostate cancer, which includes radical prostatectomy, radiation therapy, hormone therapy, cryosurgery or cryoablation, chemotherapy, and biological therapy. Also, active surveillance or ‘watchful waiting’ is a suitable option for men diagnosed with low-risk prostate cancer. It involves regular PSA (prostate-specific antigen) screening, rectal examinations, and sometimes biopsies.
It is a technique where the prostate gland, along with the surrounding tissues and few lymph nodes, are surgically removed. Radical prostatectomy can be carried out either through robotic assistance or by surgically cut opening the lower abdomen Robot-assisted surgery enables the surgeon to make more precise movements. Side effects: Urinary incontinence and erectile dysfunction
Prostate cancer cells need testosterone hormones for their growth. By stopping the production or supply of testosterone, these cancer cells die or grow slowly. Hormone therapy uses medications either to stop the body from producing testosterone or to prevent the hormone from reaching cancer cells and Performing hormone therapy prior to radiotherapy yields successful outcomes because the tumor size is reduced by hormone therapy. Side effects: Loss of muscle mass, increased body fat, loss of sex drive, hot flashes and erectile dysfunction
Cryoablation or Cryosurgery:
In this technique, the prostate tissues are frozen to kill the cancer cells. A thin needle (cryoprobe) is inserted into the prostate gland, and gases are pumped through the needle. Firstly, very cold gas is pumped, which freezes the tissues, and the second gas heats the tissues. This freezing and thawing cycle kills the cancer cells. Side effects: Erectile dysfunction, painful urination, loss of bladder control.
Chemotherapy employs drugs to kill cancer cells. Men diagnosed with advanced prostate cancer can be treated with chemotherapy. It is also an option for patients who are resistant to hormone therapy. Side effects: Hair loss, loss of appetite, nausea, and fatigue.
Immunotherapy uses the body’s immune system to fight cancer cells. A vaccine called sipuleucel-T-T, which activates the patient’s immune system to fight cancer cells, is used in immunotherapy. This treatment can improve survival in patients with metastatic castration-resistant prostate cancer. Side effects: Fever, fatigue, nausea, and joint pain.
Radiation therapy uses high energy radiation beams to kill cancer cells. Radiotherapy works by damaging the DNA of the cancerous tissues using ionizing radiation. RT is very much a technology-driven treatment modality. Thanks to the improvements in engineering and computing, RT techniques have evolved considerably over the last few years, from traditional irradiation to highly sophisticated RT techniques, such as stereotactic RT (SRT), intensity-modulated RT (IMRT), intensity-modulated arc therapy (IMAT), and brachytherapy. Radiation therapy can be done in two ways- external beam radiotherapy and brachytherapy.
External beam radiation therapy:
In this therapy, high energy beams are applied from outside of the body using linear accelerators. Usually, X-rays or protons are directed to the prostate gland to kill cancer cells. The main idea is to precisely target the cancer cells alone without causing any damage to the surrounding tissues or organs. Thus, several techniques have been developed with the aim to provide precise targeting.
3D- Conformal Radiotherapy:
The process of Radiotherapy involves the following steps; scanning, delineation of tumor and organs at risk, treatment planning, and finally, sending all data to a verification system. The main difference between 3D-CRT and IMRT lies in the treatment planning step. In 3D-CRT, the treatment planner manually sets the beam parameters, like, number of beams, direction, shape, width, height, and so on. The computer then calculates the dose distribution using this. Whereas in IMRT, the treatment planner first determines the dose distribution, and the computer then calculates the beam parameters. First, the radiologist takes a 3D image of the tumor using any of the imaging techniques, such as CT, PET, MRI, etc., and is fed to the computer. The computer then analyses the image and construct beams that fit the shape and size of the tumor. It is preferable to go for 3D-CRT when the organs at risk are under dose-limits. Also, the treatment takes only a few minutes, and the patient feels more comfortable.
IMRT involves using beams of non-uniform fluences from different directions to treat the tumor. Modulation of the fluence profile is done in such a way that a high dose is given to the targeted tissue, and a low dose is given to surrounding tissues. As mentioned earlier, it involves inverse treatment planning where the fluences are altered to match the predefined dose- distribution. IMRT involves at least two systems; (i) a treatment planning system and (ii) a system to deliver non-uniform fluences. IMRT is preferable in cases where the dose-volume is as large as 70 Gy.
Stereotactic radiotherapy (SRT):
SRT delivers precisely targeted high dose radiation beams to the cancer cells in a small number of fractions. Since prostate cells have a low alpha-beta ratio, this fractionated therapy helps in increasing the therapeutic ratio, i.e., the amount of radiation that kills prostate cancer cells to the amount that causes normal organ toxicity.
In brachytherapy, several radioactive seeds that are very small in size are placed using a needle inside prostate tissue. Brachytherapy is widely used for treating localized and early-stage cancer. Usually, older people opt for this treatment. Brachytherapy has the following benefits- low morbidity, short hospital stay, fast recovery, and cost-effective.