First, after preparation for anesthesia, pharyngoscopy and laryngoscopy or inspection of the oral cavity: The tumor is seen on the left edge of the tongue, extending to the front and side of the floor of the mouth, but not quite reaching the alveolar ridge. Subsequent transoral tumor resection: The tumor is macroscopically incised on all sides with a safety margin of 1.5 cm in the sense of a hemiglossectomy, whereby the base of the tongue is only partially resected. Resection extends forward to the floor of the mouth. Removal of the soft tissue from the bone. Removal of the external tongue muscles and sublingual gland as well as resection of the lingual nerve. Resection extends posteriorly to the posterior floor of the mouth including the glossoalveolar groove and parts of the base of the tongue. The specimen is removed and marked with a suture. A marginal sample is taken from the mucosa at the front and sides of the alveolar ridge as well as a marginal sample of basal tissue. In the frozen section, both tumor and margin samples are free of carcinoma. Thus R0 resection. Careful hemostasis. Now repositioning for continuation of the operation. First tracheostoma creation (<CLINICIAN_NAME>): A horizontal incision of about 4 cm 2 QF above the jugulum is made, sharply cutting through the skin, subcutaneous tissue as well as the platysma. The prelaryngeal musculature or infrahyoid musculature is exposed, entered in the midline and the thyroid gland is exposed. Dissection of the trachea between the cricoid cartilage and isthmus. The isthmus is cut and stitched on both sides. No major bleeding. Between the 2nd and 3rd tracheal cartilage clasp, the trachea is entered and a visual tracheotomy is created. The patient is intubated with an 8-gauge cannula. Completion of the procedure without complications. Neck dissection on both sides, neck dissection on the left first: Curved skin incision. Subsequent exposure of the digastric muscle, omohyoid muscle, sternocleidomastoid muscle and infrahyoid muscles. Expose the cervical vascular sheath, internal jugular vein, internal, external and common carotid artery. Expose vagus nerve, accessorius nerve, hypoglossal nerve. All structures are preserved, as is the cervical artery. Level I b to 5 are removed, including removal of the submandibular gland with exposure and protection of the marginal mandibular nerve. This results in the removal of levels I b to V. Subsequent careful hemostasis. No evidence of bleeding or lymph flow on final assessment. Subsequent neck dissection on the right side: In principle, this is performed in the same way as on the left side. Exposure of the aforementioned structures and preservation of these. Removal of levels I b to V, but with preservation of the submandibular gland on this side. Subsequent skin closure here in layers with insertion of a Redon drainage. Then elevation of the radial lobe (<CLINICIAN_NAME>, PJ). Palpatory identification of the distal radial artery. Marking of the flap borders (10x8cm) on the distal forearm, proximal to the flexor retinaculum, with an S-shaped incision running proximally into the cubital fossa. Incision of cutaneous and subcutaneous tissue starting proximally. Identification and visualization of the venous confluence in the cubital fossa. Identification of the cephalic vein and dissection of the vein distally with integration into the radial graft margin. Identification of the ramus externus of the radial nerve and elevation of the radial portion, leaving the peritendineum of the tendons of the brachioradialis muscle intact. Subsequent ulnar incision down to the forearm fascia. Incision of the fascia and subsequent subfascial elevation of the ulnar edge of the graft up to the tendon of the flexor carpi radialis muscle. Care is taken to leave the peritendineum on the flexor tendons and to spare the ulnar artery. Identification of the distal radial artery and trial clamping with a vascular clamp. After 5 minutes with good oxygen saturation measured by pulse oximetry (measured on the index finger), the vessels are removed with subsequent ligation (Prolene 6.0). Successive detachment of the flap pedicle from the M. pronator quadratus and M. flexor pollicis longus with ligation of the outgoing perforators using a vessel clip into the cubital fossa. Exposure and protection of the radial nerve on the medial side of the brachioradialis muscle. Exposure of the brachial artery, V. mediana cubiti, A. ulnaris. First removal of the radial artery, then of two veins of the superficial venous system. Vascular ligation using silk ligature (artery) and vascular clip (veins). Subtle hemostasis in the area of the wound bed using bipolar coagulation forceps. Then removal of split skin with the dermatome set to 8000 turns and 0.8 mm layer. A split-thickness skin graft measuring 10 x 8 cm is harvested from the right thigh. After harvesting the flap from the left forearm, the proximal incision is closed in two layers with Vicryl 3-0, Ethilon 5-0. The lifting defect of the radialis flap is adapted with 2-0 Vicryl and then the split skin is sutured in place. Split skin is stitched and applied to the dressing in the typical manner. Application of a wound dressing and a forearm splint. Completion of the graft lift without complications. Then PEG (<CLINICIAN_NAME>/<CLINICIAN_NAME>): Entering with the gastroesophagoscope and with air insufflation, pre-scintillation into the stomach. This shows a positive diaphanoscopy, therefore indication for PEG insertion. The needle is now inserted as far as it will go, but the anterior stomach wall is not penetrated. This is carried out at three different, promising sites, here also no penetration of the anterior stomach wall. The PEG was therefore discontinued and a nasogastric tube was inserted in the typical manner. The radialis flap is inserted into the defect in the mouth area: To do this, first widen the tunnel from the floor of the mouth into the soft tissues of the neck. 2 transverse fingers can be pushed through easily. Then pass the pedicle through after inserting the flap into the defect. Successive suturing of the flap into the defect with 3.0 Vicryl single button sutures, this is achieved without tension and completely. Then anastomosis of the flap pedicle. For this purpose, the superior thyroid artery is selected and conditioned. After conditioning the radial artery, suture with 8.0 Ethilon single-button sutures. After opening the clamps, good arterial flow and good venous return. Subsequent conditioning of 2 outlets from the area of the facial vein, this one close to the internal jugular vein. After conditioning of 2 venous outlets from the flap area and 2 outlets from the facial vein area, anastomosis is performed with 2.5 mm couplers. Good venous return in each case after opening the clamps, positive smear phenomenon. Overall flap also well perfused enorally. Vascular pedicle is now placed and partly fixed with sutures to prevent kinking. Subsequent irrigation of the wound area. Careful hemostasis. Wound closure in layers with insertion of a Redon drain and a flap. The procedure is then completed without complications. Patient is transferred to the intensive care unit for postoperative monitoring. Please monitor flap clinically for 5 days according to schedule, using Doppler monitoring if necessary. Feeding via the inserted PEG tube for approx. 10 days, then if necessary, nutritional support. Overall cT4 cN2c status. Wait for the final histology and presentation at the interdisciplinary tumor conference to plan further adjuvant therapy.