Learning Objectives. Head and Neck Cancer: Post-Treatment Changes. Neck Dissection Classification * Radical neck dissection. Radical Neck Dissection

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1 Head and Neck Cancer: Post-Treatment Changes Daniel W. Williams III, MD Learning Objectives In patients treated for H/N Cancer: Describe the various types of neck dissections Explain reconstruction techniques used following surgery Describe expected soft tissue changes from irradiation Recognize post-treatment imaging appearance of neck dissections, myocutaneous flaps, and radiation on CT and MRI Neck Dissection Classification * 1. Radical neck dissection (RND) 2. Modified RND 3. Selective ND ( SND + LN levels removed) 4. Extended ND (RND plus) * KT Robbins et al. Neck dissection classification update. Arch Otolaryn Head Neck Surg 2002; 128: Radical neck dissection Structures removed - LN levels I-V - SCM, IJV, SAN - SM gland Standard proc. to which other ND s compared Cummings, 4 th ed RND Normal Radical Neck Dissection

2 Modified RND Structures removed - LN levels I-V Structures preserved - 1 or more nonlymphatic structures (SCM, IJV, SAN) Modified RND Normal Cummings, 4th ed Modified RND (IJV & SCM removed) Selective Neck Dissection Preservation of 1 or more LN levels (c/w RND): - Oral cavity: SND (I-III) - OP/HP & laryngeal: SND (II-IV) - Low ant. neck ML structures: SND (VI) - Skin Ca: SND (LN levels adj. to 1 ) SND Normal Selective ND (I-III)

3 Removes: Extended ND Extended ND (incl. CN 10) - All structures removed during RND - Additional LN groups and/or non-lymphatic structures not removed at RND Carotid artery Paraspinal muscle CN s 10 or 12 Cummings, 4 th ed Imaging Appearance of ND s Depends on type of surgery RND/some MRND s: recognizable Δ s absent structures, neck contour Δ, muscle denerv atrophy / hypertrophy Some MRND/most SND s: subtle Δ s loss of fat planes, slight neck contour Δ, surgical scar, ± absent structures Complications and Pitfalls Complications Perioperative - bleeding, nerve injury, pntx, air embolus/leak, infection/abscess Postoperative shoulder syndrome, fistulas, CA rupture, IJV thrombosis, facial/cerebral edema Pitfalls MC flaps Pseudotumors IJV stump Be alert for complications and pitfalls Options in Head and Neck Reconstruction Healing by secondary intention Primary closure Skin grafts (split or full thickness) Composite grafts Flaps (local, distant pedicled, distant free) From Gurtner GC, Evans GR. Advances in head and neck reconstruction. Plast Reconstr Surg 2000;106: ; quiz 683 MC Flaps: Uses Facilitate wound closure Repair surgical defects Enables more complete removal of 1 tumor Restore optimal function (speech, breathing, mastication, swallowing) Cosmesis (recreation of facial aesthetics) Protection (carotid artery during RT, skull base, orbital apex)

4 Flap Classification Type of tissue transferred Cutaneous Myocutaneous Osteomyocutaneous Flap Classification Site of origin Local (temporalis) Regional (pectoralis major) Microvascular free tissue transfer (radial forearm, iliac crest, lateral thigh, subscapular system, jejunal, double free-flap) MC Flaps: Imaging Appearance Imaging changes usually obvious, but can be quite subtle Pearls: Compare to pre-treatment exam Read the op-note or call the surgeon!!!! Be aware of potential complications and pitfalls MC Flaps: CT/MR findings Neck contour change Fatty mass w/ muscle striations Muscle denervation atrophy over time Muscle enhancement on MR (often intense, persists many months) Rotational flaps - muscle origin remains attached; vascular pedicle visible Unusual appearing bones/other signs of surgery Neck contour change; fatty mass with muscle striations Muscle origin remains attached Rectus abdominus free flap Pectoralis major flap

5 Complications/Pitfalls Fluid collections, fistulas, IJV thrombosis, flap ischemia/necrosis, nerve injury, bone nonunion or infection Pseudotumors (muscle denerv. atrophy, muscle hypertrophy, enhancing flap muscle component) Changes or complications assoc. with primary tumor excision, ND or RT Hide early tumor recurrences from PEx Irradiation in H/N Cancer Alone ± chemo or surgery Successful RT = disappearance of tumor or major tumor volume Effects on normal tissue - acute or late/ delayed Usually with doses > 6500cGy Our task: differentiate between radiation-induced changes and tumor recurrence! Irradiation effects on normal tissue Acute during or immediately after RT tissues with rapidly dividing cells (mucous membranes, skin) rarely imaged Late/delayed months to years after RT tissues with slowly or non-proliferating cells (connective tissue, spinal cord) Expected RT Changes (CT/MRI) Reticulation/enhancement of fat Loss of fat planes betw. structures Skin and platysma muscle thickening Edema (supraglottic laryngeal, RTPS) Dense salivary glands (fatty Δ later) Lymph node enhancement Fatty marrow conversion (spine) Expected RT Changes RT Complications Dry eyes/mouth Dental caries Trismus Osteoradionecrosis Cataracts Optic neuropathy Lymphedema CNS abnl s (trans myelitis, CN palsy, pit. dysfx) Accelerated athero RT-induced tumors

6 Conclusions Perform high quality exams Learn types of ND s and MCF s your surgeons use Maintain a high index of suspicion when evaluating post-op scans (!recurrent tumor, new primary, nodes, PNS) Anticipate location of recurrences Above all, read the op note/speak to the surgeon Thanks