RT24 Prelim - Introduction to Radiation Therapy, Cancer PDF

RT24: Radiation Therapy 1st Sem, A.Y. 2024-2025 Radiation Therapy To protect healthy tissues: Using as low a dose of radiation as possible. Spreading out treatment over time Aiming radiation at a precise part of the body  Tumors or lesions is treated with cancercidal doses o...

RT24: Radiation Therapy 1st Sem, A.Y. 2024-2025 Radiation Therapy To protect healthy tissues: Using as low a dose of radiation as possible. Spreading out treatment over time Aiming radiation at a precise part of the body  Tumors or lesions is treated with cancercidal doses of ionizing radiation as prescribed by the radiation oncologist. To deliver maximum dose to the tumor while giving the minimum dose to the surrounding normal tissues or cells The aims of radiation therapy are: Curative Prophylactic Palliative Modes of Treatment ▪ Surgery ▪ Radiotherapy ▪ Cytotoxic Drugs ▪ Biologic Therapy ▪ Hormones Treatment Classifications of Treatment – Radiation Therapy Radical – if necessary, to remove all malignancy present Palliative – if radical treatment is thought to be impossible, the aim is to relieve symptoms. Radiation Oncology Team Radiation Oncologist Clinical evaluation Therapeutic decision Target volume localization Simulation & verification of treatment plan Periodic evaluation Follow-up evaluation Radiation Oncology Team Medical Radiation Physicist Beam data computerization Analysis of treatment plan Selection of treatment plan Patient contour Dose calculation Radiation Oncology Team Dosimetrist Works with the radiation oncologist and medical physicist to calculate the proper dose of radiation given to the tumor. Radiation Oncology Team Radiation Therapist / Radiotherapy Technologist Target volume localization Treatment planning simulation Treatment of patients Localization films Positioning of patients Making of blocks (photon/electron) Radiation Oncology Team Radiation Oncology Nurse Cares for the patient and family by providing education, emotional support and tips for managing side effects. Amount of dose dependent on: Size of tumor Extent of tumor Type of tumor Variation in Normal Growth Hypertrophy Metaplasia Hyperplasia Neoplasia Neoplasm Classification Carcinogens Chronic irritation Radiation Infection Hormones Worms Viruses  Patient referred for radiotherapy: a. histology – type of tumor b. stage – extent of tumor c. grade – degree of malignancy Histology 3 Major Subtypes of Cancer Sarcoma – connective tissues Carcinoma – epithelial tissues Lymphoma – blood-forming tissues Tumor Type TISSUES BENIGN MALIGNANT Fat Lipoma Liposarcoma Cartilage Chondroma Chondrosarcoma Bone Osteoma Osteosarcoma Blood vessel Hemangioma Hemangiosarcoma Glandular epithelium Adenoma Adenocarcinoma Meninges Meningioma Malignant meningioma Smooth muscle Leiomyoma Leiomyosarcoma Staging - estimation of the extent to which any tumor has spread from its primary site - could be done through: clinical staging pathological staging post-therapy staging  Stage 1. Tumor confined to organ of origin Stage 2. Local lymph nodes invaded Stage 3. Distant nodes invaded, or local spread beyond organ of origin Stage 4. Blood-borne metastases present Another system of staging used internationally: T – local extension of primary Tumor N – condition of regional lymph Nodes M – presence of Metastases beyond regional lymph nodes Grading GRADE 1 GRADE 2 GRADE 3 Low-grade Moderate/intermediate-grade High-grade Well-differentiated Moderately differentiated Poorly differentiated Relatively normal-looking cells that do Have features between grades 1 and 3 Lack normal features and tend to grow not appear to be growing rapidly and and spread more aggressively are arranged in small tubules. Types of Spreading Diffused Lymphatic Hematogenous Based on Radiosensitivity Highly Sensitive Sensitive Poorly Sensitive Reticulosis Basal Cell Carcinoma Sarcoma Medulloblastoma Epithelial Carcinoma Malignant Melanoma Neuroblastoma Carcinoma of the breast, lung, Glioma ovary Nephroblastoma Carcinoma of rectum, kidneys Treatment of Choice Surgery Radiation Cytotoxic Drugs Stomach Mouth Acute Leukemia Wilm’s Tumor Skin Choriocarcinoma Bone Uterus and Testis Burkitt’s Lymphoma Fibrosarcoma Bladder Melanoma Larynx Testis Medulloblastoma Lymphomas Signs and Symptoms of Cancer C – change in bowel or bladder A – lesion that does not heal U – nusual bleeding or discharge T – hickening or lump I – ndigestion or difficulty swallowing O – bvious change in wart or mole N – agging cough or persistent hoarseness U – nexplained weight loss P – ernicious anemia Early Detection Self-examination Periodical medical examination Cytological examination Radiological examination Highly specialized technique Types of Radiation Therapy Teletherapy Brachytherapy Kinds of Brachytherapy Interstitial Intracavitary Intraluminal Types of EBRT Three-dimensional conformal radiation therapy (3D-CRT) Intensity modulated radiation therapy (IMRT) Proton beam therapy (PBT) Neutron beam therapy (NBT) Stereotactic radiotherapy Image-guided radiation therapy (IGRT)