chemotherapy and radiotherapy in oral surgery

by Rakesh Majumder

1. CHEMOTHERAPY & RADIOTHERAPY Dept. of Oral and Maxillofacial Surgery Rakesh Majumder Roll No 01 University Roll : Final year

2. INTRODUCTION There are 4 major types of treatment for cancer — radiation, chemotherapy (often called  chemo ), surgery and biologic therapies. Chemotherapy uses very strong drugs, and radiation therapy uses high energy waves to treat the disease by killing cancer cells . Chemotherapy can be used when cancer cells have spread to other parts of the body .  Radiation therapy is targeted to localized cancer i.e., specific organs in the body where cancerous tissue is present.

3. RADIOTHERAPY Radiation prevents the cells from multiplying by interfering with their nuclear materials. Normal host cells are also affected by radiation and must be protected as much as possible during treatment. The principal methods employed are : • X-ray therapy ▪ Superficial X-ray therapy 45–100 Kv ▪ Kilo voltage X-ray therapy 300 kV • Electron therapy • Surface applicator (radium mould ) • Interstitial implantation—radium or equivalent source

4. Side Effects of Radiotherapy LONG TERM Xerostomia Increased risk of periodontal disease Caries Post radiation osteonecrosis Telangiectasia SHORT TERM Mucositis Altered taste Increased risk of infections (e.g. Candida albicans ) Trismus

5. MUCOSITIS XEROSTOMIA OSTEORADIONECROSIS

6. RADIOSENSITIZERS RADIOPROTECTORS RADIATION MITIGATORS Radiosensitisers are compounds that sensitise the tumour cells to radiation during radiotherapy • Hyperbaric oxygen • Carbogen • Nicotinamide • Metronidazole and its analogs Radioprotectors are chemical compounds that protect the nontumour (normal) cells from radiation during radiotherapy. Amifostine Nitroxides ( tempol ) Other antioxidants (glutathione; lipoic acid Radiation-induced late normal tissue toxicity includes ongoing mitotic cell death and perpetually active cytokine cascades that can lead to vascular damage, tissue hypoxia and excessive extracellular matrix deposition. Radiation mitigators aim to interrupt these cascades or intervene to prevent the perpetuation of damage and thus reduce the expression of toxicity

7. CHEMOTHERAPY Chemicals that act by interfering with rapidly growing tumor cells are used for treating many types of malignancies. As with radiation, chemicals are not very selective but affect normal cells to some extent. Most of these agents are given intravenously, but recently intra-arterial injections have been given . To reduce the toxicity of a single agent given in large quantities, multiple agent therapy is the preferred method. Many patients are given 3–5 agents at the same time. Each may work at a different point in the life cycle of the tumor cell, thus increasing effectiveness with less toxicity to the host. +

8. Side Effects of Chemotherapy LONG TERM Bone marrow suppression Increased risk of Infection Neuropathy Loss of Appetite Possible renal, pulmonary and ototoxicity. SHORT TERM Nausea and vomiting leading to enamel erosion Mucositis Skin Rash Increased bleeding

9. Chemotherapy Approaches C ombination therapy Induction chemotherapy Concomitant Chemotherapy Adjuvant Chemotherapy Palliative Chemotherapy Chemoprevention

10. CONCLUSION Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. Radiotherapy uses high-energy rays to destroy cancer cells. The chemotherapy drugs can make cancer cells more sensitive to radiotherapy. Combining both treatments is often more effective than having either treatment on its own . The oncologist will decide which treatment is most effective for the patient. If the disease is spreading rapidly, chemotherapy will be the most likely approach. Radiation therapy may make more sense for particular types of cancer that are affecting smaller areas.