hdr brachytherapy- role of rt in oncology

brachytherapy ppt

1. HIGH DOSE RATE BRACHYTHERAPY, CLINICAL CONSIDERATIONS DR. NISMA SENIOR RESIDENT

2. Radiation therapy is a clinical modality which uses ionizing radiations for treatment of patients with malignant neoplasias ( and occasionally benign diseases ). RADIOTHERAPY TELETHERAPY BRACHYTHERAPY

3. BRACHYTHERAPY : The sources are placed directly into the treatment volume or near the treatment volume. Classification of brachytherapy based on dose rate Low dose rate (LDR) - 0.4 - 2 Gy /h Medium dose rate (MDR) - 2 - 12 Gy /h High dose rate (HDR) - > 12 Gy /h Dose : 1 Gy = 1 joule per kg Dose rate: dose per unit time

4. HDR brachytherapy: Dose delivered is >12gy/ hr Fractionation with atleast 6 hr interval Short OTT Get efficient cell killing with less normal tissue toxicity

5. 4 R’S OF RADIOBIOLOGY 1. Repair of Sub-lethal damage: Repair of the sub-lethal damage is the most important radiobiological process defining the dose rate effect. 2. Re-oxygenation: Slow Process, radiation delivery completes very fast in few days. 3. Redistribution 4. Repopulation: Slowest process. It does not start as overall treatment time is less than the time repopulation start.

6. Advantages of brachytherapy Improved localized dose delivery to the target A high dose can be delivered to tumor with s harp dose fall-off outside the target volume • Better conformal therapy Inverse square law   : The intensity of an x-ray beam is governed by the inverse square law. This law states that the radiation intensity from a point source is inversely proportional to the square of the distance away from the radiation source. In other words, the dose at 2 cm will be one-fourth of the dose at 1 cm.

7. Indications: Intracavitary : Sources are placed into a body cavity

8. Interstitial: Sources are implanted into the tumor volume .

9. Intraluminal : Sources are inserted into a lumen . Eg : Ca esophagus, ca bronchus, ca urethra, ca biliary tract Surface plaque : Sources are loaded into a plaque which is brought into contact with a skin surface lesion

10. Work Flow of HDR Brachytherapy:

11. TOXICITY Head and neck Acute: haemorrhage, infection, pain, edema , mucositis Chronic: ORN, neuropathy, trismus , speech swallowing problems Breast Acute: hematoma , edema , infection , dermatitis Chronic: skin telanctesias , s/c fibrosis, fat necrosis Cervix Proctitis , cystitis, vaginal stenosis Prostate Urethritis, cystitis, proctitis , sexual dysfunction

12. Clinical Outcomes with HDR brachytherapy

13. 2022 ( AUGUST) : 15 2023 (TILL MARCH) : 13 ICBT 10 7 IVBT 3 4 ISBT 1 1 ILBT 1 1

14. THANK YOU