Radiation Therapy Flashcards Preview

Fundamentals of Molecular Medicine > Radiation Therapy > Flashcards

Flashcards in Radiation Therapy Deck (26):
1

 

 

 

Discovery of X-rays

 

 

 

Roentgen 1895

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Discovery of Radioactivity

 

 

 

Becquerel1896

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Definition of Radiation

 

 

 

Radiation=Energy

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Diagnostic vs. Therapeutic  Radiation

 

 

 

Therapeutic radiation is of higher energy

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Radiation Machines

 

 

 

Superficial  machines, orthovoltage,  Cobalt, Linear Accelerators 

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Radiation Sources

 

 

 

Cobalt, Radium, Iridium, Iodine, Gold,Cesium,Palladium

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Mechanism of Radiation Cytotoxicity

 

 

 

DNA injury

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CANCERS COMMONLY TREATED  EFFECTIVELY  WITH  RADIATION THERAPY  ALONE

 

Squamous cell carcinomas of head and neck Squamous and basal cell carcinomas of skin Cervical cancers

Vaginal cancers

Prostate cancers Hodgkin's Disease NonHodgkin's lymphoma

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CANCERS COMMONLY TREATED EFFECTIVELY WITH THE COMBINATION OF SURGERY AND RADIATION THERAPY

 

Head and neck cancers Brain tumors

Uterine cancer

Colorectal cancer Breast cancer

Soft tissue sarcomas

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CANCERS COMMONLY TREATED WITH THE COMBINATION  OF CHEMOTHERAPY AND  RADIATION THERAPY

 

NonHodgkin's lymphoma Hodgkin's Disease

Anal cancer

Esophagus cancer

Head and neck cancers

Inflammatory breast cancer

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Very Sensitive Tumor to Radiation

 

 

Germ cell tumors

Lymphomas

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Moderately  Sensitive

 

 

 

Adenocarcinomas

Squamous cell carcinomas

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Less Sensitive to Radiation 

 

 

Osteogenic sarcomas

Renal cell carcinomas

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RADIATION DOSES REQUIRED FOR 90% liKEliHOOD OF CONTROL OF SQUAMOUS AND ADENOCARCINOMAS

 

 

Microscopic disease: 1em of disease :

2 em of disease:

 

5000 cGy in 25 treatments

6000 cGy in 30 treatments

7000 cGy in 35 treatments

 

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INDICATIONS FOR RADIOTHERAPY

 

 

Cancers which can't be resected or resection would cause unacceptable cosmetic or functional deficit

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TECHNIQUES  IN RADIOTHERAPY

 

Physical Aspects (Exclude as much normal tissue as possible)

Beam  Orientations

Beam Shape

Radiation Energy

Source Distance

Number of Fields

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Fractionation

 

 

 

FractionationDividing total radiation dose into number of small treatments

18

 

 

 

BRACHYTHERAPY  INDICATIONS

 

Definitive Treatment

Boost Treatment

Recurrent Disease

Pediatrics

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Acute Toxicity

 

 

 

Dependent upon total dose, fraction size, interval between fractions

20

 

 

 

Late Toxicity

 

 

 

Dependent upon total dose and fraction size

21

 

 

 

FUTURE DIRECTIONS IN RADIOTHERAPY

 

Increasingly localized treatment

Altered  fractionation

Concurrent systemic agents

Assays for tumor response

Assays for normal tissue response

Tailoring of treatment based on genetic profile

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Rationale for Non-Surgical Treatment

A image thumb
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Rationale for Fractionation

A image thumb
24

 

 

 

Senstitivity of Tumors to Radiation

A image thumb
25

 

 

 

Indirect Action vs. Direct Action of DNA Damage

A image thumb
26

 

 

 

Diagnostic vs. Therapeutic 

RAD

 

 

Diagnostic vs. Therapeutic Radiation— Low energy photons for diagnostic — High Energy radiation for therapeutic. 

RAD — Radiation absorbed Dose

Centigrade and RAD used interchangeably.

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