Introduction To Clinical Oncology - PowerPoint Presentation

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Introduction To Clinical Oncology

3 rd Stage Surgery Introduction To Oncology 2nd Lecture

Clinical Radiation Therapy Sources & Machines;

Clinical Radiation Therapy Sources & Machines can be divided into 2 basic types; 1. External Beam Radiation Therapy(EBRT) ,or Deep X-ray Beam Radiation Therapy(XBRT) , or Teletherapy ;

A. Cobalt Units. B. Linear Accelerator (linac). C. Specially Modified Linear Accelerator; to produced special technique like; e.g. (3DCRT, IMRT, IGRT, SRS, SBRT, VMAT, IMAT, TOMOTHERAPY). D. Intra-operative Radiation Therapy.

Cobalt-60 Teletherapy Unit;

a linear accelerator (linac);

Clinical Radiation Therapy Sources & Machines;

2. Internal Radiation Therapy , or Sealed Source Radiotherapy, or Brachytherapy ; according to dose delivered;

A. Low Dose Brachytherapy. B. High Dose Brachytherapy. Or according to half life of radiation source used ; A. Permanent Brachytherapy. B. Temporary Brachytherapy. Or

according to site of radiation source ; A. Intracavitary Brachytherapy . B. Interstitial Brachytherapy. C. Intraluminal Brachytherapy.

Ring–tandem and ovoid–tandem applicators;used in treatment of Gynecological tumor by

Brachytherapy applicators:

- Combination of Chemotherapy with Radiation Therapy in treatment of cancer;

Some chemotherapy drugs; can enhance the effect of radiation by increasing cellular sensitivity.

Chemotherapy drugs ; are used to eliminate , the residual tumor cells after surgery. In combination with Deep X-ray Therapy; chemotherapy agents such as Doxorubicin often acts as radio sensitizer and increase the effect of treatment.

Radio- protectors ; such as Amifostine , limits the effect of radiation on the normal cells , then decreasing treatment side effect.

Contraindication to RTx.= Deep X-Ray Therapy ;

1- Anemia, leukopenia . 2- Cachexia. 3- Grave patient states. 4- Acute septic states.

5- Decompensated state of heart, liver, kidneys. 6- Active TB (Tuberculosis ). 7- Poor performs state ( KPS or ECOG ). 8- Growth of tumor into great blood vessels.

Is

RTx. Safe ? We ask our self question; Many advances have been made in this branch or field ; to ensure it remains safe and effective .

The treatment plan and equipment ; are constantly checked to ensure proper treatment is being given. Multiple healthcare professionals develop and review the treatment plan; to ensure that the target area , is receiving the dose of radiation needed.

Side effect of RTx. ;

- Skin tenderness; are generally limited to the area receiving radiation. - Unlike chemotherapy , radiation usually doesn't cause hair loss or nausea.

- Most side effects; begin during the 2nd or 3rd week of treatment.

- Side effects may; last for several weeks , after the final treatment. - Appetite and weight loss. - Oral and Dental cares .

- Flushing of nose .

- Dry mouth and loss of taste.

- Neck and Jaw tightening .

- Xerostomia ( decrease salivation ).

- Hypothyroidism.

- Emotional side effects ; ( confusion , fear , anxiety, …… ) .

Toxicity of Deep X-Ray Therapy;

The severity of normal tissue reaction to RTx. Depend on ; 1. Total Dose. 2. Dose Fraction. 3.

Treatment Volume. 4. Radiation Energy. 1- Skin Toxicity; (Acute skin reaction); 2- Hematologic Toxicity; (myelosuppression).

3- Gastrointestinal Toxicity; A. Acute Complication; ( nausea , vomiting , and diarrhea). B. Long-term GIT Complications; 4- Genitourinary Toxicity; (Cystitis , Vesicovaginal fistula and ureteral strictures , Vulvo -vaginitis , Adhesions and stenosis of vagina )

Toxicity of Deep X-Ray Therapy;

1- Skin Toxicity; - Acute skin reaction; commonly is characterized by erythema , desquamation , and pruritis . And should resolve completely within 3 weeks of the end of treatment. - Topical corticosteroids

or moisturizing creams; may be applied several times per day for symptomatic palliation and to promote healing . - The perineum is at greater risk for skin breakdown than other areas, because of its increased warmth and moisture and lack of ventilation. - The patient should be keep the perineal area clean and dry , to prevent ulceration and breakdown of skin.

2- Hematologic Toxicity; - The volume of marrow irradiated and the total radiation dose determine the severity of

myelosuppression. - In adults; 40% of active marrow is located in the pelvis. 25% of active marrow is located in the vertebral column. 20% of active marrow is in the ribs and skull. - Extensive radiation of these sites may cause significant myelosuppression.

3- Gastrointestinal Toxicity;A. Acute Complication; ( nausea , vomiting , and diarrhea); - commonly occur ; 2 to 6 hours, after abdominal or pelvic irradiation. - the severity of the effect;

increase with the fraction size and treatment volume.

-

treatment involves;

supportive therapy with hydration and administration of antiemetic's and antidiarrheal.

B. Long-term GIT Complications;

- Chronic diarrhea, Obstruction ; caused by bowel adhesions, and fistula formation , are serious complication of intestinal irradiation , that occur in fewer than 1% of cases.

4- Genitourinary Toxicity; . Cystitis; is characterized by inflammation of the bladder with associated symptoms of pain , urgency , hematuria , and urinary frequency. Diagnosis of radiation may be made after a normal urine culture results has been obtained. . Vesicovaginal fistula and ureteral strictures ; are possible long-term complications of radiation therapy.

. Vulvo -vaginitis ; pelvic irradiation often results in ; erythema , inflammation , mucosal atrophy , inelasticity , and ulceration of vaginal tissue. . Adhesions and stenosis of vagina ; are common and are result in pain on pelvic examination and intercourse. Treatment involves vaginal dilation.