Hypofractionation is subdivided into moderate hypofractionation and ultrahypofractionation.
Conventional fractionation is defined as external-beam radiation therapy (EBRT) with a fraction size of 180-200 cGy.
Moderate hypofractionation is defined as EBRT with a fraction size between 240 cGy and 340 cGy.
Ultrahypofractionation is defined as EBRT with a fraction size ≥500 cGy.
The fraction size gap (>340 cGy but <500 cGy) is a relatively little studied and little used intermediate range outside of the scope of these guidelines.
Moderate hypofractionation (between 240 cGy and 340 cGy) should be offered to men with low-risk prostate cancer who decline active surveillance and receive EBRT to the prostate with or without radiation to the seminal vesicles.
Moderate hypofractionation should be offered to men with intermediate-risk prostate cancer receiving EBRT to the prostate with or without radiation to the seminal vesicles.
Moderate hypofractionation should be offered to men with high-risk prostate cancer receiving EBRT to the prostate but not including pelvic lymph nodes.
Moderate hypofractionation should be offered regardless of patient age, comorbidity, anatomy, or urinary function to patients who are candidates for EBRT, but physicians should discuss the limited follow-up beyond 5 years for most randomized clinical trials that have evaluated moderate hypofractionation.
In patients with localized prostate cancer who are candidates for EBRT, a regimen of 6,000 cGy delivered in 20 fractions of 300 cGy and a regimen of 7,000 cGy delivered in 28 fractions of 250 cGy are suggested, because they are supported by the greatest evidence.
Ultrahypofractionated EBRT (≥500 cGy per fraction) may be offered as an alternative to conventional fractionation (180-200 cGy per fraction) to men with low-risk prostate cancer who decline active surveillance and choose to receive active treatment with EBRT.
Ultrahypofractionation may be offered as an alternative to conventional fractionation to men with intermediate-risk prostate cancer receiving EBRT. The task force strongly encourages that these patients be treated as part of a clinical trial or multi-institutional registry.
In men with high-risk prostate cancer receiving EBRT, the task force does not suggest offering ultrahypofractionation outside of a clinical trial or multi-institutional registry because of insufficient comparative evidence.
Ultrahypofractionated prostate EBRT of 3,500 to 3,625 cGy in 5 fractions of 700 to 725 cGy to the planning target volume may be offered to low-risk and intermediate-risk patients whose prostate size is <100 cm3.
Five-fraction prostate ultrahypofractionation at doses greater than 3,625 cGy to the planning target volume is not suggested outside of a clinical trial or multi-institutional registry because of the risk of late toxicity.
Five-fraction prostate ultrahypofractionation using consecutive daily treatments is not suggested because of the potential increased risk of late urinary and rectal toxicity.
Image-guided radiotherapy (IGRT) is universally recommended when delivering moderately or ultrahypofractionated EBRT.
For more information, please go to External Beam Radiotherapy in Prostate Cancer.
For more Clinical Practice Guidelines, please go to Guidelines.
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Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Prostate Cancer External-Beam Radiation Therapy (EBRT) Clinical Practice Guidelines (2018) - Medscape - Nov 29, 2018.