De-Intensification Radiotherapy Postoperative Head Neck

Overview

In patients with squamous cell carcinoma of the oral cavity, the oropharynx and larynx with \>= pT3 and or pN+ postoperative radio - or radiochemotherapy is the standard of care. Postoperative radiochemotherapy is indicated in patients with multiple lymph node metastasis, lymph node metastasis with extracapsular spread and or R1/2 resection. Locoregional control rates are over 80% after surgery and radio(chemo)therapy. But many patients suffer from therapy-related long-term side-effects, like xerostomia, dysphagia, fibrosis, trismus etc. The aim of this study is to investigate if depending on primary tumor stage, quality of resection ( resection margin) and number of lymph node metastasis and performed neck dissection an adapted de-intensified dose- and target volume concept may be performed without reducing locoregional-control but with reducing radiotherapy-related side-effects.

The study is a non-randomized phase-II trial. In total there are 3 therapy arms. Patients are assigned to one of these therapy arms according to the tumor status and the quality and kind of surgery. The aim of this study is to investigate if a risk-adapted dose- and target-volume concept in clearly defined patient groups is possible to individualize postoperative radiotherapy without reducing locoregional-control but with reducing radiotherapy-related side-effects. There are two main issues to investigate: 1. Dose prescription in primary tumor region: In this study it should be investigated if a dose reduction to 56 Gy in the primary tumor region is possible, if the resection margin is \>= 5mm, tumor stage is \<=pT2 and if there are no other risk factors like perineural spread or peritumoral lymphangiosis. 2. Target volume definition in elective lymph node levels It should be investigated if ipsilateral cervical lymph irradiation alone allows adequate locoregional control in selected patients: ipsilateral lymph node metastasis \<=3 and contralateral pN0 (adequate contralateral selective neck dissection performed) or contralateral cN0 (in patients with strictly ipsilateral localized tumors of the oral cavity or oropharynx) Considering these facts 3 therapy groups are possible: A: Criteria: * pT2, R ≥ 5 mm, L0, Pn0 * 3 lymph node metastasis or patients with \< 3 ipsilateral lymph node metastasis and a bilateral primary tumor without adequate contralateral neck dissection Intervention: * Reduction of radiation dose in the primary tumor region to 56 Gy, * Elective Radiotherapy of both neck sides B: Criteria: •\> pT2 and/or R \< 5mm and/or L1 and/or Pn1 •≤ 3 ipsilateral lymph node metastasis (and contralateral pN0 (\>= 6 resected lymph nodes) or contralateral cN0 in patients wih strictly ipsilateral localised ( \>= 5 mm distance from midline) cancer of the oral cavity or oropharynx Intervention •No dose reduction in primary tumor region (prescribed dose in primary tumor region: 64 Gy) •Reduction of target volume: only elective radiotherapy of the ipsilateral neck, no contralateral neck irradiation C: Criteria * pT2, R ≥ 5 mm, L0, Pn0 * 3 ipsilateral lymph node metastasis (and contralateral pN0 (\>= 6 resected lymph nodes) or contralateral cN0 in patients wih strictly ipsilateral localised ( \>= 5 mm distance from midline) cancer of the oral cavity or oropharynx Intervention •Reduction of radiation dose in the primary tumor region to 56 Gy, AND •Reduction of target volume: only elective radiotherapy of the ipsilateral neck, no contralateral neck irradiation In all arms the dose prescription for the lymph node regions is as follows: •elective lymph node level (either ipsi- or bilateral): 50 Gy •lymph node level with lymph node metastasis without extracapsular extension: 56Gy * lymph node level with lymph node metastasis with extracapsular extension: 64 Gy In all arms simultaneously chemotherapy is recommended in the following cases: * lymph node metastasis with extracapsular extension •\>= 3 lymph node metastasis All patients are stratified according to HPV status. Additional investigations: * swallowing endoscopy (before, 6 and 24 months after radiotherapy) * translational research (especially individual radiosensitivity, immunologic parameters in peripheral blood during treatment) * QoL