3Upper and Lower Gingiva Retromolar Trigone or (Retromolar Gingiva ANATOMYHard PalateUpper and Lower GingivaLipOral TongueAnt 2/3Buccal MucosaFloor Of mouthBuccal MucosaRetromolar Trigone or (Retromolar Gingiva
6NotesRetromolar trigone??:- Apex in line with maxillary tuberosity (behind last molar teeth), the lateral border extend with buccal mucosa, medially it blends with anterior tonsillar pillar, base is formed by the last lower molar and the adjacent gingivolingual sulcus.
8Other TrigonesTrigone of bladder: a triangular region of the wall of the urinary bladder, the three angles corresponding with the orifices of the ureters and urethra; it is an area in which the muscle fibers are closely adherent to the mucosa.
9Carotid trigone: the triangular area bounded by the posterior belly of the digastric muscle, the sternocleidomastoid muscle, and the anterior midline of the neck.
10Olfactory trigone: The triangular area of gray matter between the roots of the olfactory tract.
11Oral TongueIntrinsic Muscles (speech)Longitudinal, vertical and transverseExtrinsic Muscles (move body)Genio, hyo, stylo glossusThere are six pairs of muscles that form the oral tongue. Three of these muscles are extrinsic, while the other three are intrinsic.The extrinsic muscles include the genioglossus, hyoglossus, and styloglossus.The intrinsic muscles include the lingual, vertical, and transverse muscles.The former primarily move the body of the tongue, while the latter alter the shape and conformation of the tongue during speech and swallowing.
18Four taste qualities, a novel taste, that is referred by the Japanese word umamiwhich means delicious, ‘‘fifth taste’’.Umami taste is found in a diversity of foods (e.g. fish, meat, milk, tomato and some vegetables) and is elicited by monosodium glutamate and certain ribonucleotides.
19Aging, pregnancy and menopause Aging, pregnancy and menopause. Poor dentition and hygiene, alcoholism and/or excessive smoking are common conditions that affect taste.Patients with xerostomia, Sjogren syndrome, vitamin and zinc deficiency liver and kidney disorders, endocrine disorders, diabetes mellitus, psychological disorders,central nervous system disorders, and surgical procedures around the chorda tympani or gloss opharyngeal nerve.
20Floor of MouthA semilunar space extending from the lower alveolar ridge to the undersurface of the tongue.The floor of the mouth overlies the mylohyoid and hyoglossus muscles.
2110-12 SMALL DUCTS TOSUBLINGUAL FOLDS (PLICAE SUBLINGUALIS)
35ORAL CAVITY BASICS ASK YOUR SELF THREE QUESTION? Is it small (T1 or T2 ) or large (T3 or T4)?.Is the lesion Central or Lateralized?.Is the Nodes negative or Positive?.
36RulesThe closer to the midline the primary, the greater the risk of bilateral cervical nodal spread.The mucosa of the upper and lower alveolus and hard palate is fixed to the underlying periosteum so invasion of the adjacent bone occurs relatively early making these tumors less suitable for primary radiotherapy
37Early LesionSurgical resection: where rim rather segmental resection should be performed. Situations where removal of the bone is required to achieve clear margin.Re-resection should be performed to achieve clear histological margins if the initial resection has positive margins.
38submandibular and subdigastric nodes Lymphaticsfirst echelonSecond echelonupper gingivalower gingivahard palateretromolar trigonesubmandibular and subdigastric nodessubdigastric nodesanteriorcervical nodesincidence of clinical nodal positivity at presentationaccording to anatomic subsite:20 – 30% for gingival and retromolar trigone tumors (with slightly higher risk of nodal disease for lower gingival vs upper gingival tumors) and 10% for hard palate tumors- incidence of clinically positive bilateral nodes rareincidence of occult nodal disease overall: 20%
43In Early stage T1 and T2 surgery results equal to RT. So How to choose?
44LIP Surgery may be preferred in : - T1 lesion with good functional and cosmetic outcome.- Young patient with outdoor sunlight exposure.- Diffuse superficial lesion of the vermillion, or presence of severe actinic keratosis adjacent to carcinoma.
45N0 diseaseIn the N0 neck, occult metastases are estimated to occur in 5% to 10% of cases.Therefore, elective neck dissection is not routinely performed in the N0 neck.Neck dissections are generally performed when cervical metastases are clinically or radiographically apparent.
46WHEN? Primary Radiotherapy Target Volume: Tumor with a margin Tumor with a margin+first echlon lymph nodes.Tumor with a margin + whole neck .WHEN?
47LIP What is the likely diagnosis? How would you treat this patient (describe your technique in detail)
49Tumor Thickness in Oral Tongue Po demonstrated that tumor thickness in oral tongue carcinomas was the only significant factor that had significant predictive value for subclinical nodal metastasis, local recurrence, and survival in multivariate analysis.With the use of 3-mm and 9-mm division, tumor of up to 3 in mm thickness is associated with an 8% risk of subclinical nodal metastasis, zero local recurrence, and 100% 5-year actuarial disease-free survival; tumor thickness of more than 3 mm and up to 9 mm carried a risk of 44% subclinical nodal metastasis, 7% local recurrence, and 76% 5-year actuarial disease-free survival; tumor of more than 9 mm carried a 53% risk of subclinical nodal metastasis, 24% local recurrence, and 66% 5-year actuarial disease-free survival
50External beam alone may not be very successful. Boost using brachytherapy is recommended.
51Oral TongueBefore external-beam RT, the cancer is photographed and diagrammed to document its extent at the time of the implant.Sometimes, the anterior and posterior borders of the lesion are tattooed with two tiny (1–2 mm) marks.Under no circumstances should the ink that is used to tattoo the patient be injected under pressure (e.g., with a syringe), because the ink may diffuse over a large area.
52If teeth with metal fillings lie against the tongue or buccal mucosa, a thin layer of gauze (a few millimeters thick) is inserted between the teeth and tongue or buccal mucosa to prevent a high-dose effect secondary to scattered low-energy electrons.
56Advanced StagePatients with resectable disease who are fit for surgery should have surgical resection with reconstruction.Patients with node positive should be treated with modified radical neck dissection.Elective dissection of the contralateral neck should bee considered if the primary tumor is locally advanced arises form the midline or there are multiple ipsilateral nodal involvement.
57Advanced Stage Ctn When Concurrent CRT Only Tumor can not be resected.General condition is inadequate.Patient doesn’t wish to go for surgery.Nodal level I to IV should be irradiated.
58Nodal DiseasePatients with N1 disease should be treated by chemoradiotherapy to the primary and node.Patient with N2 or N3 disease should be treated by chemoradiotherapy followed by planned neck dissection.
59When Chemotherapy is not Suitable Cetuximab with radiotherapy should be considered.Where radiotherapy to be used without chemotherapy or cetuximab,A modified fractionation schedule should be considered.
60Management Gingival and hard palate cancer Retromolar trigone cancer Early (T1 – 2) tumorsSurgery is recommended over radical irradiation due to the high incidence of bone involvement – irradiation risks bone exposure after treatment of the tumorVery superficial tumors may be treated with radical irradiationAdjuvant irradiation is added for adverse primary (i.e., high-grade mucoepidermoid or adenoid cystic pathology) or neck pathologyAdvanced (T3 – 4) tumorsSurgery and adjuvant irradiation is recommendedUnresectable disease may be treated with adjuvant irradiation followed by attempted resection or hyperfractionated irradiation aloneRetromolar trigone cancerearly (T1 – 2) tumors: radical irradiation is recommended over surgery due to more favorable morbidity profileadvanced (T3 – 4) tumorssurgery and adjuvant irradiation is recommendedunresectable disease may be treated with neoadjuvant irradiation followed by attempted resection or hyperfractionated irradiation alone
61Results gingival cancer hard palate cancer retromolar trigone cancer M. D. Anderson (see Leibel, p. 475) treated 48 patients with radical irradiationsurvival: 5YOS of 46%patterns of failure: local control of70% for T1 – 2,59% for T3,29% for T4hard palate cancerMemorial (Evans. Am J Surg 142: ) treated 49 patients with surgery with or without adjuvant irradiationsurvivalsurgery alone: 5YDFS of 75% for stage I, 46% for stage II, 40% for stage III, and 8% for stage IV diseasesurgery and adjuvant irradiation 5YDFS of 25% for stage IV diseaseretromolar trigone cancerM. D. Anderson (Lo. IJROBP 13: ) treated 159 patients with retromolar trigone and anterior tonsillar pillar tumors with radical irradiation with surgery reserved for salvagesurvival: 5YCSS of 83%patterns of failure: local controlafter irradiation: 70% for T1 – 2, 76% for T3, and 60% for T4after surgical salvage: < 90% for all T stages
62Standard ttt T1-T2,N0 Any site (except retromolar trigone) Surgery alone with staging neck sampling:Plus adjuvant radiotherapy for high risk situationMicroscopic margins <5mm (irrespective of intra-operative revision or additional post-resection sampling of the surgical site)> 1 additional features at primary:Poorly differentiatiedPeri-neural spreadAngiolympatic invasionLymph node involvement at pathology:Extracapsular extension in positive lymph nodesMultiple lymph nodes>3 cm lymph nodes
63Standard ttt. T1-T2 N0 Retromolar trigone Radiotherapy Alone with surgical Salvage 60 Gy in 25 fractions ?4-6 MV beam qualityHomolateral wedge pair (preferable) in lateralised lesions: disease limited to 1 cm of palate involved disease limited to 1 cm of tongue involved Parallel opposed as necessary 3 phases (including cord shield where appropriate) Augment posterior neck with electrons after cord Pb where appropriate Ant or Ant/Post ‘low’ neck parallel opposed (4-6 MV) or hemisplits in unilateral techniques
64Standard ttt. AnyT, N+ or T3-T4, N0 (except retromolar trigone) M0 Surgery with neck dissection +/- adjuvant post-operative radiotherapy:Plus adjuvant radiotherapy for high risk situationMicroscopic margins <5mm (irrespective of intra-operative revision or additional post-resection sampling of the surgical site)> 1 additional features at primary:Poorly differentiatiedPeri-neural spreadAngiolympatic invasionLymph node involvement at pathology:Extracapsular extension in positive lymph nodesMultiple lymph nodes>3 cm lymph nodesSurgically ‘unstaged’ neck:No surgery to a neckEspecially if imaging incomplete
65Standard ttt. POST-OPERATIVE XRT 60 Gy in 30 fractions for original site of gross disease where feasible using reducing field techniques66 Gy in 33 fractions to sites of positive margins50 Gy to other potentially involved nodal sitesParallel opposed (4-6 MV) or ipsilateral wedge pair for lateralized lesions
66RADIOTHERAPY ALONE Retromolar Trigone (AnyT, Any N) Primary radiotherapy indicated all cases. Exception is gross bulk disease extending through bone and/or skin involvement where surgery should be considered followed by adjuvant radiotherapy.All Oral cavity T3-T4 or Any N +Where surgical morbidity at primary site anticipated and considered not appropriatewhere patient declines surgeryor neck disease is unresectable and primary not yet treated surgicallyUnresectable neck and primary already resected:assess risk to the primary and consider inclusion in plan for neck to administer 70 Gy in 35 fractions with Cisplatin
67Doses & Beam arrangement Dose fractionation schedules +/- chemotherapy70 Gy in 35f with Cis-Platin (Intergroup usually) or60 Gy in 25f (reserve for frail or ‘patient preference’ declining ‘standard’ treatment)Beam arrangement (technique)Parallel opposed or angled down wedge pair as necessary with (4-6 MV)Ant or Ant/Post ‘low’ neck if parallel pairAugment posterior neck with electrons after cord Pb
68Targets for non-surgical treatments (any T, any N, M0) -PMH Primary and gross neck node(s):Phase 1 : 1.5 cm CTV margin (superior: mastoid to inferior: clavicle)Phase 2 : 1.5 cm CTV margin (cord shield, including custom ‘Step back’ shape for posterior mid-line disease)Phase 3 : 0.5 cm CTV margin on primary or gross nodes
69Lymph nodes management Node inclusion:Zones 2 to 5 included to adjuvant dose (50 Gy in 25 fractions or equivalent) (Leuven/Rotterdam consensus)Retropharyngeal nodes if extensive other nodal involvementDose fractionation:Gross nodes always receive full dose with minimum CTV margins as used for the primary, unless planned surgery is undertaken.Gross nodes undergoing planned surgery (see below) should receive a minimal ‘microscopic’ dose, depending on the overall dose-fractionation chosen, prior to planned surgery.Uninvolved node regions within the risk zones should be treated to a ‘microscopic’ dose depending on the overall dose-fractionation chosen.
74Organ PreservationYou still can Try CRT if organ preservation is required. (provided salvage surgery may still be an option. e.g. patient reliable for good follow-up. Surgeon reliable for good surgery.Famous Laryngeal preservation trials:-Veterans Affairs (larynx neoadjuvant), EORTC (Hypopharynx neoadjuvant),(RTOG larynx Concurrent CRT value).-Urba et al JCO 2006(NEW is the use of concurrent CRT if good response to the neoadjuvant treatment.Veterans affair NEJM 1991, EORTC JNCI 1996, RTOG NEJM 2003, Urba et al 2006
76ImmobilzationMax. Extension still possible for easily shielding of the oral cavity.Tongue bite? What was the question?You said before that when we want to protect the upper jaw and when we want to protect the lower jaw? But here I am protecting the whole cavity so whats the aim.?
77Portal ArrangementsOpposed –lateral photon fields, with the patient immobilized in supine position are used for treatment of most cancers :oral cavity, Larynx, pharynx.
78In General: Either it will be Superior border: Determined by the location of the known disease and likely spread pattern.In General: Either it will be1- At the base of skull when we want to include the retropharyngeal node, e.g. Hypopharynx.
79Superior border: Nasopharynx Hypopharynx Oropharynx Oral cavity: LarynxAbove skull base. because the primary at skull base.Skull base? Retropharyngeal nodeszSkull base? Primary at skull base.Do you want lymph node?So skull base/If not take only a margin (1 to 2 cm).Glottic? Above the glottis.Supraglottic? Lymph nodes so skull base.Subgltic (very rare) only margin above the larynx.Glottic with extensive supra? Skull base.
81Eisbruch et al. established dose thresholds for the parotid gland: mean dose ≤24 Gy and ≤ 26 Gy for unstimulated and stimulated salivary flow,respectively. Also, partial volume thresholds were established:67%, 45%, 24% of the parotid gland volumereceiving ≥ 15 Gy, ≥ 30 Gy, ≥ 45 Gy, respectively. They observed that if the dose to the parotid glands exceeds (one or more of) these thresholds, Parotid salivary flow would significantly decrease
82Lucite oral cavity mouthpiece fabricated at the University of Wisconsin for patients with oral cavity carcinomas. Upper dentition or maxillary alveolus links to u-shaped notch and tongue rests beneath smooth undersurface of mouthpiece. Note embedded solder wire in mouthpiece floor to facilitate visualization of tongue positioning at the time of simulation and beam design