eContour

62 y/o M with Stage IVA (T3N2cM0) SCC of the supraglottic larynx arising from the L aryepiglottic fold and invading inner cortex of the thyroid cartilage.

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He was treated with definitive chemoradiation using IMRT and concurrent cisplatin. The primary tumor and bilateral involved LNs received 70 Gy in 35 fractions. Entire larynx and high risk neck including bilateral levels II-III and IV on the L received 59.4 Gy in 33 fractions. Low risk elective neck including level IV on the R and upper level II received 54 Gy in 33 fractions.

  • Always cover bilateral levels II-IV for supraglottic primary due to rich lymphatics.
  • For N0, cranial border of level II can be lowered to where the posterior belly of the digastric crosses the IJV.
  • For N+, level II should be covered to the base of skull (lateral border of C1) due to risk of retrograde lymph flow.
  • Add level VI for subglottic extension or HPX involvement.
  • Definitive RT dose and coverage (per Eisbruch et al Sem Rad Onc 2002):
    • CTV70 = GTV + 5-10mm, carving out bone/air. Avoid SIB, esp >2Gy per fraction, due to risk of late toxicity.
    • CTV59.4-63 = CTV70 + entire larynx (top thyroid notch to bottom cricoid), paraglottic and pre-epiglottic space, pyriform sinuses, vallecula, and up to 1cm BOT, as well as high risk first echelon nodes
    • CTV54 = low risk elective nodes (ie upper level II, RP)
  • Consensus Guidelines for neck nodes.
  • Consensus Guidelines for H&N OARs, with details of brachial plexus delineation per Hall et al IJROBP 2008 (see "Pearls").

  • Brachial plexus delineation per Hall et al IJROBP 2008:
    • Contour C5 and T1.
    • Contour subclavian artery.
    • Contour anterior and middle scalene muscles from origin (C5) to insertion (first rib).
    • Contour brachial plexus:
      • 5mm brush
      • Contour neural foramina from C5 to T1.
      • On CT slices without neural foramina, contour ONLY space between ant/mid scalene muscles.
      • Contour neurovascular bundle along subclavian artery to just below the clavicle.

Also available: ARROCase