106 年 12 月修訂 Protocol of Radiotherapy for Head and Neck Cancer Indication of radiotherapy Indication of definitive radiotherapy with or without chemotherapy (1) Resectable, but medically unfit, or high surgical risk (2) Unresectable Indication for adjuvant radiotherapy (1) pt3* or pt4 primary (2) postive nodal disease (pn1-3) (3) perineural invasion (4) lymphatic/vascular invasion *pt3 not regarded as adverse feature in glottic and supraglottic cancer Indication for adjuvant CCRT (1) extracapsular nodal spread (2) Positive resection margins (3) optional for multiple LNPs/ advanced disease Simulation and Treatment Planning 1. For all cancers in head and neck region, mask with head support is suggested 2. A CT scan of head and neck with 2.5 to 5 mm contiguous slices in immobilization system is required for all patients 3. Contrast (50-100 ml ) enhancement is suggested, for more accurate GTVs contouring 4. 3D conformal RT or Intensity modulation radiotherapy (IMRT) and image-guided radiotherapy (IGRT) is preferred Radiation Treatment Fields Gross Tumor Volume (GTV) is defined as all known gross disease as defined by clinical physical examination and image findings. Gross tumor includes the primary tumor and macroscopically involved lymph nodes. Clinical Target Volume (CTV) includes all the risk areas of subclinical involvement around GTV and neck lymphatic prophylaxis. The volume of CTV is dependent on tumor location, tumor behaviors, tumor staging and physicians preference.
Planning Target Volume (PTV) provide margin around the CTV to compensate for variability in treatment position setup. For non-igrt patients: 3-5 mm margin is added to CTV For IGRT patients: 1-5 mm margin is added to CTV Margins of expansion may be modified for special condition, such as overlapping with critical organ or other concerns on set-up error. Subsites: Oral cancer (lip, oral cavity) Oropharyngeal cancer Hypopharyngeal cancer Laryngeal cancer (glottis, supraglottic) Sinus tumors (ethmoid sinus, maxillary sinus) Salivary gland tumors Radiation dose To minimize toxicity, < 2 Gy/fraction might be adopted for dose > 70 Gy Oral cancer (lip and oral cavity) LN region (sites of suspected subclinical spread) Oropharyngeal cancers
LN region (sites of suspected subclinical spread) Hypopharyngeal cancer LN region (sites of suspected subclinical spread) Uninvolved nodal stations: 44-64Gy
Laryngeal cancer (cancer of glottis and supraglottis) T1, N0: 63-66 Gy in 2.25-2.0 Gy/fraction T2,N0: 65.25-70 Gy in 2.25-2.0 Gy/fraction T3 and/or N(+) Primary lesion: Conventional fractionation: 70-72 Gy Uninvolved nodal stations: 44-64Gy Primary: 60-66 Gy 5-6 fractions per week Paranasal sinus cancer (maxillary sinus and ethmoid cancer) LN region (sites of suspected subclinical spread) Uninvolved nodal stations: 44-64Gy
Salivary gland cancer - T4b disease or gross residual disease Photon or photon/electron therapy Dose Primary and gross adenopathy: 70-72 Gy Postoperative RT Photon or photon/electron therapy Dose Primary: 60-66 Gy 5-6 fractions per week 5-6 fractions per week Constraints of OAR Organ Spinal cord Brainstem Optimization parameter Dmax 45 Gy ( 50 Gy in difficult cases) Dmax 50-54 Gy ( 55-60 Gy in difficult cases) Dmax 10 Gy Dmax 54 Gy Dmean 35 Gy Lens Optic nerves/optic chiasm Eyes Mandible Dmax 65 Gy or V70 1% Cochlea Dmean 50 Gy
Parotid gland Reference Dmean 26 Gy (at least 1 gland) Or D50 30Gy 1. NCCN Clinical Practice Guidelines in Oncology- Head and Neck Cancer v.2. 2017 2. Bernier J, Domenge C, Ozsahin M, et al. Postoperative irradiation with or without concomitant chemotherapy for locally advanced head and neck cancer. N Engl J Med 2004;350:1945-1952. 3. Cooper JS, Pajak TF, Forastiere AA, et al. Postoperative concurrent radiotherapy and chemotherapy for high-risk squamous-cell carcinoma of the head and neck. N Engl J Med 2004;350:1937-1944. 4. RTOG. RTOG - Guidelines for CT-based delineation of lymph node levels in the N0 neck. 5. Gregoire V, Levendag P, Ang KK, et al. CT-based delineation of lymph node levels and related CTVs in the node-negative neck: DAHANCA, EORTC, GORTEC, NCIC,RTOG consensus guidelines. Radiother Oncol 2003;69:227-236. 6. Ang KK, Trotti A, Brown BW, et al. Randomized trial addressing risk features and time factors of surgery plus radiotherapy in advanced head-and-neck cancer. Int J Radiat Oncol Biol Phys 2001;51:571-578. 7. Pfister DG, Laurie SA, Weinstein GS et al. American Society of Clinical Oncology clinical practice guideline for the use of larynx-preservation strategies in the treatment of laryngeal cancer. J.Clin.Oncol. 2006;24:3693-704. 8. Foote RL, Foote RT, Brown PD, Garces YI, Okuno SH, Strome SE. Organ preservation for advanced laryngeal carcinoma. Head Neck 2006;28:689-96. 9. Lambert L, Fortin B, Soulieres D et al. Organ Preservation with Concurrent Chemoradiation for Advanced Laryngeal Cancer: Are We Succeeding? Int.J.Radiat.Oncol.Biol.Phys. 2009. 10. Grégoire V, Ang K, Budach W et al..delineation of the neck node levels for head and neck tumors: a 2013 update. DAHANCA, EORTC, HKNPCSG, NCIC CTG, NCRI, RTOG TROG consensus guidelines. Radiother Oncol. 2014; 110:172-81. 11. Trifiletti DM, Smith A, Mitra N, et al. Beyond Positive Margins and Extracapsular Extension: Evaluating the Utilization and Clinical Impact of Postoperative Chemoradiotherapy in Resected Locally Advanced Head and Neck Cancer. J Clin Oncol. 2017 May 10;35(14):1550-1560. 12. Masterson L, Moualed D, Masood A, et al. De-escalation treatment protocols for human papillomavirus-associated oropharyngeal squamous cell carcinoma. Cochrane Database Syst Rev 2014;2:CD010271.