Treatment Break http://isocentre.wikidot.com/forum/t-259642/treatment-break Posts in the discussion thread "Treatment Break" - A patient is being treated with a radical course of RT for h & n ca, conventional fractionation of 200 cGy per fraction, once a day for 35 fractions. After 4 wks. of treatment, he must miss the subsequent 2 weeks because of an out-of-town family crisis. Once treatment is restarted, what dose is needed to make up for the time he missed? (posted by ADJUVANT) Sat, 18 Apr 2026 12:57:15 +0000 http://isocentre.wikidot.com/forum/t-259642#post-852488 Treatment Break http://isocentre.wikidot.com/forum/t-259642/treatment-break#post-852488 Wed, 18 Aug 2010 08:50:49 +0000 AAM 61952 The options are:

  • leave the 2 week break to stand and suffer a 10-14% reduction in local control outcome (-0.6-1.0 Gy/[day of prolongation])
  • compensate for the break:
    • accelerate after the break
      • 40Gy/20Fx @ 1/day = 4 weeks (conventional fractionation)
      • 10/7 break = 2 weeks
      • 30Gy/15Fx @ 2/day = 1 week + 2.5 day ('conventional' acceleration) with 6 hour delay. Maybe even weekend treatment?

Effect of 2-3 day prolongation will be small. His acute effects will be small as his mucosa will be undergoing ACCELERATED REPOPULATION.

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