General Flashcards
History
Site specific symptoms (Dysphagia, otalgia, odynophagia), weight.
Trismus, Alcohol, tobacco (5-25x risk), betel and areca nuts (OC), Plummer-vinson syndrome, HPV (OP), HIV, EBV (NPX), HIV, immunosuppression, sun exposure (skin), previous RT, occupations and environmental exposures.
Ill-fitting dentures may contribute to OC SqCC.
Assess social support, smoking, alcohol.
Physical
Head and neck exam, noting teeth condition, cranial nerves, mirror and flex laryngoscopy (esp for larynx), palpation of mass in mouth
Bimanual floor of mouth exam with attention to tongue mobility, trismus, neck nodes, dysphagia, otalgia.
Work Up
FNA biopsy of node if possible
Labs: CBC, CMP, TSH, EBV IgA/DNA titers for NPX.
Primary Imaging: CT of the neck, possible MRI
Staging Imaging: CT chest, PET for T3 or node positive
Special imaging: direct laryngoscopy with biopsies, consider videostrobe
Special: dental, port, PEG tube, nutrition, (audiology), speech and swallowing evaluation
DDX
SCC, Melanoma, lymphoma, sarcoma (Can say these 4 for basically any site), Plasmacytoma, angioma, glomus tumors
CT Simulation
Scan from above head down to carina.
Set isocenter anterior to C2 if treating the bilateral neck.
IV contrast. 2 mm slice thickness.
Oral devices: Dental trays (ideally 3-5 mm thick) vs. tubular or “popsicle” bite blocks.
Daily IGRT. IMRT: Randomized data for OPX, paranasal sinus and NPX.
Primary Volumes
CTV1: GTV + 0.5 cm isotropic, larger if tumor is poorly defined. Crop at natural borders for spread.
CTV2: GTV + 1.0 cm isotropic.
CTV3: CTV2 + regional ENI without margin. Highly dependent on nodal status. For N+ patients, ENI are extended 2 cm cranial and caudal from any pathological lymph nodes. The SCM is included 2 cm above and below any pathological nodes in case of suspected muscle involvement.
SIB to 33-35 fx. 33 fractions 5 fractions per week, 35 fractions may be 5 or 6 fractions per week.
RTOG doing 6 fx/week, but 5 fx/wk might be the safer answer based on [GORTEC 99-02].
Doses: HR/IR/LR Volumes. Ranges from 1.6 Gy per fraction to 2.12 Gy per fraction. SIB up to 2.22 Gy acceptable.
70/63/56 (2 Gy, 1.8 Gy, 1.6 Gy) in 35 fractions (5 or 6 fractions per week [DAHANCA]).
69.96/59.4/54.12 (2.12 Gy, 1.8 Gy, 1.64 Gy) in 33 fractions (5 fractions per week).
Intermediate risk volumes: Controversial. Some believe only high and low risk volumes are needed.
CTVHR_70 = GTV + 5 mm.
CTVIR_63 = GTV + 10 mm while including the lymphatic compartment (1st echelon).
CTVLR_56 = Low-risk nodes (2nd echelon) and contralateral 1st echelon if uninvolved.
For cancer of unknown primary, the majority consider potential sites of primary disease as LR or IR.
Post Op Volumes
Preoperative GTV
CTV1: Preop GTV + 0.5 cm isotropic, larger if tumor is poorly defined. Crop at natural borders for spread.
CTV2: If R0, preop GTV + 1.0 cm isotropic. If non-radical resection, CTV2 includes CTV1 with a 0.5 cm margin. Margin may be larger in case of poorly defined tumor. Disease-specific high risk anatomical regions could be added, such as resected nodal disease with ENE (Fig 2c).
CTV3: CTV2 + primary surgical bed outside preop GTV + 1.0 cm + regional ENI without margin. Highly dependent on nodal status. For N+ patients, ENI are extended 2 cm cranial and caudal from any pathological lymph nodes. The SCM is included 2 cm above and below any pathological nodes in case of suspected muscle involvement.
CTVHR_63-66: SM+ or ECE.
CTVIR_57.6-60: Bed + 1.0-1.5 cm and nodes (1st echelon).
CTVLR_50-54: low-risk nodes (2nd echelon) and contralateral 1st echelon if uninvolved.
Treat tracheostomy site if trach was placed through tumor or when tumor involved subglottis. In the IMRT era, contour the trach site and use surface dosimeters to ensure surface dose 60 Gy (does not require donut bolus).
Treatment Planning
CTV1 must be covered with 95-107% of the prescribed dose. A maximum volume of 1.8 cc may receive > 107% (110%) of the prescribed dose to CTV1.
CTV2 and CTV3 must be covered with 95% of the prescribed doses.
The 95% isodose curve for PTV1, PTV2 and PTV3 must be as close to the delineation of PTV1, PTV3 and PTV3 respectively, as achievable (DAHANCA).
Prescription Guidelines
Prescription dose is the isodose which encompasses at least 95% of the PTV (RTOG - V100 ≥ 95%).
No more than 10% (20%) of the PTV should receive > 110% of its prescribed dose (RTOG).
No more than 1% of the PTV should receive < 93% of its prescribed dose (RTOG - V93% ≥ 99%).
No more than 1% or 1 cc of the tissue outside PTVs should receive > 110% of the dose Rx’d to the primary PTV (RTOG).
100% PTV covered by 100% (Mayo).
95% of PTV getting 100% prescription, “most” covered by 98% IDL (DFCI).
95% of the volume of all PTVs must receive the prescribed dose with a minimum dose (defined as dose to 99% of the PTVs) greater than 93% of the prescription dose (RTOG).
If the above cannot be met, then ensure coverage of CTVs!
99% CTV covered by 100% (MDACC).
CTV1 must be covered with 95-107% of the prescribed dose. A maximum volume of 1.8 cc may receive > 107% (110%) of the prescribed dose to CTV1.
CTV2 and CTV3 must be covered with 95% of the prescribed doses.
The 95% isodose curve for PTV1, PTV2 and PTV3 must be as close to the delineation of PTV1, PTV2 and PTV3 respectively, as achievable (DAHANCA).
