Hypofractionation Radiation Therapy

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Hypofractionation:
    • Larger fraction size (600 to 800 cGy) compared with conventional fractionation (180 to 200 cGy)
    • Fractions delivered several days apart
    • Lower total dosage (2100 to 3200 cGy) than
      conventional fractionation (7000 cGy)
    • Shortened overall treatment duration
      compared with conventional fractionation
  • Hypofractionation:
    • Is the administration of high-dose-per-fraction (HDPF) radiation:
      • In which only one or two fractions are given per week
    • This technique has evolved for the treatment of malignant melanoma:
      • Which generally is perceived as being radioresistant
  • Conventional fractions of 200 cGy delivered 5 days a week:
    • Allow normal tissues and tumor cells to recover during the intervals between fractions
  • Experimental in vitro data have shown that malignant melanoma cells are better at repairing radiation-induced sublethal damage compared with other cells:
    • This finding may explain the long-standing notion that melanoma is intrinsically “radioresistant”
  • HDPF regimens:
    • Deliver higher doses of radiation per fraction (600 cGy twice a week or 800 cGy once weekly):
      • With the aim of overcoming the reparative capacity of the tumor cells by increasing the damage per fraction
  • In retrospective analyses, response rates have been shown to correlate with dose per fraction but not with the total dose delivered:
    • However, a prospective randomized trial (RTOG 83–05) found no therapeutic advantage in a comparison of HDPF (800 cGy once a week up to a total dose of 3200 cGy) and conventional fractionation (250 cGy daily, 5 days a week, for a total of 5000 cGy):
      • Although no therapeutic advantage was seen, the shorter delivery time of HDPF radiation allows earlier initiation of systemic therapies if applicable
  • Moderately hypofractionated radiation (225 cGy per fraction):
    • Has demonstrated superior results for early-stage larynx cancers treated with radiotherapy alone:
      • This is currently considered the standard of care in this setting
  • Additionally, a regimen commonly referred to as quad shot:
    • Which was originally developed for advanced pelvic tumors:
      • Is sometimes applied for palliation of tumors in the head and neck
    • This involves cycles of a 1480 cGy course of radiotherapy delivered in four fractions over the course of 2 days:
      • Which can be repeated multiple times over a period of weeks or months depending on the treatment response
      • Aside from the demonstrated efficacy of this regimen, it also allows significant advantages in terms of patient convenience in the palliative setting
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Published by Rodrigo Arrangoiz MS, MD, FACS, FSSO

My name is Rodrigo Arrangoiz I am a breast surgeon/ thyroid surgeon / parathyroid surgeon / head and neck surgeon / surgical oncologist that works at Center for Advanced Surgical Oncology in Miami, Florida. I was trained as a surgeon at Michigan State University from (2005 to 2010) where I was a chief resident in 2010. My surgical oncology and head and neck training was performed at the Fox Chase Cancer Center in Philadelphia from 2010 to 2012. At the same time I underwent a masters in science (Clinical research for health professionals) at the University of Drexel. Through the International Federation of Head and Neck Societies / Memorial Sloan Kettering Cancer Center I performed a two year head and neck surgery and oncology / endocrine fellowship that ended in 2016. Mi nombre es Rodrigo Arrangoiz, soy cirujano oncólogo / cirujano de tumores de cabeza y cuello / cirujano endocrino que trabaja Center for Advanced Surgical Oncology en Miami, Florida. Fui entrenado como cirujano en Michigan State University (2005 a 2010 ) donde fui jefe de residentes en 2010. Mi formación en oncología quirúrgica y e n tumores de cabeza y cuello se realizó en el Fox Chase Cancer Center en Filadelfia de 2010 a 2012. Al mismo tiempo, me sometí a una maestría en ciencias (investigación clínica para profesionales de la salud) en la Universidad de Drexel. A través de la Federación Internacional de Sociedades de Cabeza y Cuello / Memorial Sloan Kettering Cancer Center realicé una sub especialidad en cirugía de cabeza y cuello / cirugia endocrina de dos años que terminó en 2016.

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