Treatment Processes and Effectiveness

"The goal of radiation therapy is to maximize the therapeutic ratio; to maximize the delivered dose to the target (tumor) and minimize dose to the normal tissue."

3 Different types of therapy given:

The type of radiation given is dependent on the type of cancer the patient has.

  • External Radiation

    When a machine outside the body directs high-energy toward the part of the body intended to undergo treatment.

Lung cancer treatment
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  • Internal Radiation

    When a radioactive source is put inside the body into or near the tumor. (Also called brachytherapy)

Internal Radiation
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  • Systemic Radiation

    When radioactive drugs are given by mouth or put into a vein to travel throughout the body.

Systemic Radiation
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Gamma and x-ray therapy are types of photon therapy.

Electron and proton beam therapies are exactly what they sound like, they use electron or proton beams (respectively) instead of the gamma or x-ray photons.

  • Electron-beam radiation cannot travel very far through tissue, so they are often more useful for skin cancers.
  • Proton therapy uses a machine called a synchrotron or cyclotron to speed up protons to create higher energy, then they are targeted to the radiation target. Proton therapy appears to be able to go through tissue just as easily as x-ray therapy, but has less radiation dosage.


A Few Studies on Effectiveness:

  • A study from 2010-2013 of 65 women with breast cancer, after undergoing a lumpectomy and whole breast irradiation
    • Results: "a second breast conservation was achievable in 90%, with a low risk of re-recurrence of cancer in the ipsilateral breast using adjuvant partial breast re-irradiation."
    • Conclusion: "This finding suggests that this treatment approach is an effective alternative to mastectomy."
  • A study examining "the impact of brachytherapy boost (BB) and external beam radiotherapy (EBRT) dose-escalation on overall survival (OS) for women with cervical cancer receiving postoperative chemotherapy and radiation (CRT) for a positive margin following hysterectomy."
    • Results: 630 women who received CRT, 53% received EBRT alone and 47% received EBRT+BB, and 82% of those 630 women "had chemotherapy initiation within 2 weeks of radiation, suggesting concurrent delivery."
    • Conclusion: "The addition of BB to standard CRT improved OS for women with cervical cancer and a positive margin after hysterectomy. No consistent survival benefit was seen to EBRT dose-escalation beyond 5040 cGy."
  • A Mayo Clinic study evaluating the benefit of radiation therapy on cutaneous T-cell Lymphoma
    • Results: "Skin-directed radiation therapy demonstrated 99% response rate and 80% complete response rate after treatment regardless of involvement, severity, histopathologic sub-type, dose, or fractionation."
    • Conclusion: "Radiation therapy is a well-tolerated treatment option for properly selected patients with cutaneous T-cell lymphoma."


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