Oral Cavity Flashcards
Oral cavity unresectable oral tongue
“Three volume: 6996/5940/5412 (2.12/1.8/1.64) 33 fx with chemo
Two volume: 7000/5600
Another option: IMRT to 50 Gy then boost with intraoral cone to total BED of >91 Gy. Use 6-15 MeV electrons with intraoral cone
PET at 3 months then elective neck dissection if incomplete response
In oral cavity, acceptable plans can be difficult to achieve due to proximitiy of the mandible to tumor. With modern arc IMRT, acceptable plans can now be generated, but the procedure still has high adverse effects”
“CTV neck: levels Ia, Ib-IV. Include IX (buccofacial) for buccal involvement, on ipsilateral side. Include V if ≥2 nodes positive. On contralateral side cover I-IV.
5 mm CTV-P1 and 10 mm CTV-P2 per standard.
Unilateral oral cavity
“Controversial
Indications: well lateralized alveolar ridge, buccal, floor of mouth, or retromolar trigone N0-N2a. Consider for N2b. Consider also for oral tongue >1 cm away from midline N0-N1
“
“CTV neck: levels Ia, Ib-IV. Include IX (buccofacial) for buccal involvement, on ipsilateral side. Include V if ≥2 nodes positive. On contralateral side cover I-IV.
5 mm CTV-P1 and 10 mm CTV-P2 per standard.
5-yr bilateral or contralateral neck failures in 4.3%
Oral cavity post-op
Indications: T2 with greater than 5 mm depth (RTOG 0920), or depth 10 mm (per neck dissection trial), inadequate neck dissection, multiple nodes positive, ECE, PNI, LVSI”
“Can do SLN for T1-T2 if depth <4 mm
Neck dissection: Ipsilateral dissection for T2-T4. Optional for T1. Dissect levels Ia-III and include level IV for N+ (V optional). Contralateral neck dissection for N+, and offer if tumor approaches midline.”
“66 Gy for positive margin or ECE (SIB to 1.6.-1.8 daily to low risk)
60 Gy for node positive neck, dissected neck, and intermediate risk (PNI, LVI, T4, close margin in 30 fx (SIB 1.6-1.8 Gy daily to low risk). Lower risk area to 50-56 Gy
Typically two volume approach”
“CTV neck: levels Ia, Ib-IV. Include +IX (buccofacial) for buccal involvement, on ipsilateral side. Include V if ≥2 nodes positive. On contralateral side cover I-IV.
There is growing evidence to omit RT to a dissected N0 neck if pN0 and PET negative (Lowe, Contreras). In undissected neck, follow Biau guidelines.
CTV-P: post-op bed + 1-1.5 cm margin (see post-op section)
Hard palate salivary tumor
Indications: node positive, intermediate or high grade, close or positive margins, PNI, LVI
“66 Gy for positive margin or ECE (SIB to 1.6.-1.8 daily to low risk)
60 Gy to tumor bed, involved neck, dissected neck, and intermediate risk (PNI, LVI, T4, close margin in 30 fx (SIB 1.6-1.8 Gy daily to low risk).
Lower risk area to 50-56 Gy
70 Gy if gross disease still present
Two volume: 60 Gy in 30 fx with SIB 1.6-1.8 Gy daily to lower risk areas”
For adenoid cystic hard palate tumor, if tracing PNI cover hard palate, greater and lesser palatine foramen up PPF and at least some of V2 to foramen rotundum and probably vidian canal. For extensive PNI consider covering VII via greater petrosal nerve and more of V2
Submandibular gland tumor
“Adenoid cystic: RT is not required for completely resected T1 per NCCN
NCCN all others: RT not required for T1-T3 if resected even if node positive(?)”
“Can include Ib-III if N+ or T3-T4 tumor
For submandibular, if tracing for PNI trace V3 lingual nerve to foramen ovale and ALSO cover CN XII. Lingual nerve and XII both run sort of medial to mandible to skull base. If extensive PNI consider covering chorda tympani and VII. If mental nerve involvment, remember mental nerve, V3, runs through mandible bone so trace this.”
Parotid tumor
(Indications: large size, positive or close margins, PNI, high grade, nodes)”
“malignant salivary tumors: mucoepidermoid, acinic, SCC, adenocarcinoma, adenoid cystic, malignant myoepithelial
benign salivary tumors: Warthin tumour, also known as papillary cystadenoma lymphomatosum, monomorphic adenoma or adenolymphoma, low grade mucoepidermoid, acinic, pleomorphic adenoma”
“66 Gy for positive margin or ECE (SIB to 1.6.-1.8 daily to low risk)
60 Gy to tumor bed, involved neck, dissected neck, and intermediate risk (PNI, LVI, T4, close margin in 30 fx (SIB 1.6-1.8 Gy daily to low risk).
Lower risk area to 50-56 Gy
70 Gy if gross disease still present
Two volume: 60 Gy in 30 fx with SIB 1.6-1.8 Gy daily to lower risk areas”
“Parotid: cover pre-and post auricular nodes, level II-III at least (up to Ib to IV, or entire neck if N+).
For PNI trace CNVII to base of skull. Include auriculotemporal nerve in parapharyngeal space and consider V3 foramen ovale if extensive PNI”
Nasal vestibule
SCC 80%. Treat like skin cancer
“If T1-T2, treat with definitive RT. Better cosmetic outcomes than surgery
Treat nodes for T3, T4: level IA-II, facial”
Possible techniques: Put wax or wet gauze in nose. Cover nose with wax bolus to even dose for electron fields. Lead cutout on machine or on face
“Consider HDR brachy vs external beam, electrons only, 2 cm margin
If treating nodes, can do lateral photons to nodes and appositional electron boost. Or 4:1 6MV and 20 MeV photon electron mix to the nose then electrons only to facial lymphatics mustache field”
“AJCC groups these in nasal cavity and sinuses.
Other staging is Wang classification:
T1: superficial
T2: extends to skin of nose, upper lip, or nasal septum
T3: extends to bone, or fixed to bone or deep muscle”
Lip
“If T1 or T2 not involving commisure, surgery is an option.
Leibel: surgery if <3 cm and not involving commisure. Only treat nodes if involved. Some will treat with definitive RT if poorly differentiated”
“If choosing not to resect, EBRT 66-70 Gy in 30 fractions. For EBRT use electrons or orthovoltage
Or 50 Gy EBRT plus 20-35 Gy LDR
LDR alone to 60-70 Gy
HDR alone to 45-60 Gy in 3-6 fx, or HDR boost to 21 Gy in 3 dx”
Hyperextend the neck. Use bite block to move hard palate out of field. For electron boost, put lead covered in wax behind lips
Lip T3
Include nodes for T3-T4. May need to do surgery first then adjuvant RT. Surgery is preferred for large lesions >4 cm
“primary tumor with 2 cm margin. Opposed laterals to nodes first then boost primary
Lower lip: submental, submandibular, and subdigastric nodes, anterior border 1 cm in front of mandible, superior - split horizontal ramus of mandible, posterior = midvertebral body, inferior = above arytenoids
For upper lip may include mustache field, possibly in addition to above
Might include levels III-IV for advanced tumors”
