Intensity-modulated radiation therapy (IMRT) with concurrent taxane-based chemotherapy for locally-advanced head and neck cancer(LAHNC): Feasibility, technique, and toxicities

Abstract

5536 Background: Chemotherapy given concurrently with radiation is proven to improve tumor survival in LAHNC at the expense of higher toxicity. IMRT for LAHNC provides a means to minimize dose to sensitive organs. Our initial experience with concurrent IMRT and taxane-based chemotherapy in 83 LAHNC patients is presented. Methods: In order to simplify IMRT planning, a differential IMRT dose plan is developed for all head and neck structures. Daily fractions of 2.1Gy are delivered to gross disease with +/-5% homogeneity (69.3Gy in 33 fxs), simultaneously with 1.7Gy to prophylactic nodes (56.1Gy, homo +8 to -5%). 50% of the volume of sensitive tissue (oral cavity, parotids, back of neck, and larynx/trachea) are limited to ≤25Gy. Weekly paclitaxel 30mg/m2 and carboplatin AUC 1 were given concurrently to all 83 patients, and 40 with N2 or N3 disease also received weekly induction chemotherapy with paclitaxel 60mg/m2 and carboplatin AUC2. Chemo was held for ANC<1000, plts<100k, or gr4 mucositis Results: All 83 patients had AJCC III or IV nonmetastic disease: sinus-5, NPC-9, OP-44, OC-6, larynx-13, hypo-6. This regimen is highly feasible. 2 patients discontinued treatment early into treatment for non-toxicity related reasons (progression in lungs). Only 2 patients required a radiation break greater than 1 week. 28% required temporary PEG (none long-term). Only one patient (T4N0 hypopharynx) is still trach-dependent but has good swallowing function. Grade 3 mucositis occurred in 57% (2%Gr4) and gr3 dermatitis in 37%. There were no pts with nadir sepsis nor sig nephropathy or GI toxicity. One patient with a large base of skull tumor died 1 month after completion from carotid rupture. Xerostomia is ≤gr1 in all patients. Conclusions: IMRT with paclitaxel and carbo for LAHNC is extremely feasible using differential IMRT target dosing. Doses to sensitive non-target structures (oral cavity, trachea/larynx, back of neck, parotids) can be minimized (≤25Gy) and dose homogeneity to gross tumor held within +/-5% to avoid long-term morbidity. Early toxicities are low. Tumor control and survival data will also be presented. No significant financial relationships to disclose.