What Are the Pros and Cons of Radiation Therapy for Prostate Cancer?

Radiation therapy for prostate cancer is a medical name, applicable to early prostate cancer T1 ~ 2N0M0, feasible radical radiation therapy.

Radiation therapy for prostate cancer

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Radiation therapy for prostate cancer is a medical name, applicable to early prostate cancer T1 ~ 2N0M0, feasible radical radiation therapy.

Chinese name

Radiation therapy for prostate cancer

Radiation therapy for prostate cancer

1. Early prostate cancer T1 2N0M0, radical radiation therapy is feasible.

2. Local advanced prostate cancer T3 4N0M0 or T1 4N1M0, local radiation therapy combined with hormone therapy.

3. After the prostate cancer tumors remain, the capsule is invaded or PSA is increased, and postoperative radiation therapy is feasible.

4. Palliative radiotherapy, such as analgesic treatment of bone metastasis pain, local prostate radiation to reduce symptoms of urinary tract or rectal obstruction.

Extensive metastases, cachexia, etc. cannot tolerate radiation therapy.

1. Explain the purpose and effect of the treatment to the patient before the operation, strengthen the confidence to overcome the disease, and explain the precautions to obtain the active cooperation of the patient.

2. Whole body preparation The patient's whole body condition can directly affect the effect of treatment, so a comprehensive examination should be performed before treatment. Anemia should be corrected, systemic infections should be treated, and comorbidities should be controlled. Improve the patient's overall condition from all aspects, improve the body's immunity, and improve the treatment effect.

Radiotherapy methods include external irradiation and interstitial implantation. Three-dimensional conformal radiation therapy or intensity-modulated conformal radiation therapy can increase tumor radiation dose and reduce early and late complications of radiation.

Routine external exposure

(1) Treatment position and positioning: prone or supine position, fixed position.

(2) Positioning under the simulator.

(3) Pelvic irradiation field: The four-field irradiation method of the anterior and posterior fields and the lateral fields is adopted. The irradiation fields include prostate and pelvic lymph nodes.

(4) Prostate irradiation field: The four-field irradiation method of the front and back fields and the lateral fields is used to irradiate the prostate, and try to protect the surrounding normal tissues such as the bladder and rectum.

2. Intensity-modulated conformal radiation therapy and conformal radiation therapy

(1) Treatment position and fixation: prone or supine position.

(2) CT simulation: CT scan simulation is performed after the phantom is fixed, and the position of the patient, the center of the shooting field, and the skin reference point mark are determined under the CT simulator.

(3) Intensity-modulated conformal or three-dimensional conformal plans: Draw target areas on CT, GTV, CTV, PTV, and normal tissues and organs. Three-dimensional reconstruction of the target area and normal organs, the most commonly used irradiation field is 6-8 fields coplanar irradiation. Calculate isodose curves and dose-volume histograms (DVH). Use integral lead block or multi-leaf grating (MLC) for conformal radiotherapy or use multi-leaf grating IMRT.

(4) Verification of IMRT plan: dose intensity verification, dose distribution verification and absolute dose measurement verification.

(5) Calibration and field verification: The CT simulation positioning machine is used to calibrate the field and other centers and various irradiation parameters, and the field electron imaging system is used to shoot the field verification film under the accelerator.

(6) Plan execution.

3. Irradiation dose The total pelvic radiation dose is usually 45-50Gy / 5 weeks, and then the field is reduced to a local prostate supplement of 20Gy. The total dose of conventional external irradiation is usually 65 ~ 70Gy / 7 ~ 8 weeks. The daily PTV dose is 1.8 to 2.0 Gy, 5 times a week, and the field is irradiated four times a day. When intensity-modulated conformal radiation therapy or conformal radiation therapy is used, the local radiation dose can exceed 70 Gy.

4. Tissue transplantation irradiation is suitable for early prostate cancer with good prognosis. Sources of permanent particle implantation include 125 iodine (125I) and 103 palladium (103Pd). Tissue irradiation sources also include 192 iridium (192Ir). During inter-tissue irradiation, a three-dimensional treatment plan should be made to make the prostate dose distribution uniform. During particle implantation treatment, CT is performed for quality assessment (particle reconstruction and dose check) after implantation. External dose or particle implantation supplement can be used for insufficient dose.

1. Observe the acute adverse reactions of the gastrointestinal tract and bladder during radiotherapy and treat them symptomatically.

2. Long-term adverse reactions include sexual dysfunction, long-term toxicity of rectum and bladder.

3. Particle implantation has certain adverse reactions, which can produce urethral stricture, rectal bleeding, sexual dysfunction and so on.

4. With hormone therapy, when the prostate tumor is huge, you can also use hormone therapy for 2 months before radiation therapy to reduce the tumor after radiation therapy to reduce the irradiation volume and reduce adverse reactions.

5. When intensity-modulated conformal radiation therapy or particle implantation, do dose verification and plan design to ensure dose accuracy.