Feasibility of intensity-modulated and image-guided radiotherapy for functional organ preservation in locally advanced laryngeal cancer

Purpose: The study aims to assess the feasibility of intensity-modulated and image-guided radiotherapy (IMRT, and IGRT, respectively) for functional preservation in locally advanced laryngeal cancer. A retrospective review of 27 patients undergoing concurrent chemoradiation for locally advanced laryngeal cancers (8 IMRT, 19 IGRT) was undertaken. In addition to regular clinical examinations, all patients had PET imaging at 4 months and 10 months after radiotherapy, then yearly. Loco-regional control, speech quality and feeding-tube dependency were assessed during follow-up visits. Results: At a median follow-up of 20 months (range 6-57 months), four out of 27 patients (14.8%) developed local recurrence and underwent salvage total laryngectomy. One patient developed distant metastases following salvage surgery. Among the 23 patients who conserved their larynx with no sign of recurrence at last follow-up, 22 (95%) reported normal or near normal voice quality, allowing them to communicate adequately. Four patients (14.8%) had long-term tube feeding-dependency because of severe dysphagia (2 patients) and chronic aspiration (2 patients, with ensuing death from aspiration pneumonia in one patient). Conclusions and Clinical Relevance: Functional laryngeal preservation is feasible with IMRT and IGRT for locally advanced laryngeal cancer. However, dysphagia and aspiration remain serious complications, due most likely to high radiation dose delivery to the pharyngeal musculatures. © 2012 Nguyen et al

Feasibility of Tomotherapy-Based Image-Guided Radiotherapy for Locally Advanced Oropharyngeal Cancer

PURPOSE: The study aims to assess the feasibility of tomotherapy-based image-guided (IGRT) radiotherapy for locally advanced oropharyngeal cancer. A retrospective review of 33 patients undergoing concurrent chemoradiation for locally advanced oropharyngeal cancers was conducted. Radiotherapy planning, treatment toxicity and loco-regional control were assessed. RESULTS: At a median follow-up of 32 months (6-47 months), no patient developed loco-regional recurrence. Two patients (6%) developed distant metastases. Grade 3-4 acute toxicity was respectively 72% and 25% for mucositis and gastrointestinal toxicity. Two patients (6%) had long-term dependence on tube feedings. Dose-volume histogram demonstrated excellent target volume coverage and low radiation dose to the organs at risk for complications. CONCLUSIONS AND CLINICAL RELEVANCE: IGRT provides excellent loco-regional control but acute toxicity remains significant and needs to be addressed in future prospective trials. The feasibility of Tomotherapy to decrease radiation dose to the normal tissues merits further investigations

Dose-volume .histogram in a patient with T3N0M0 supraglottic laryngeal cancer illustrating the potential of image-guided radiotherapy to deliver a high radiation dose to the gross tumor while sparing the radiosensitive normal organs.

<p>Mean tumor dose: 75.4 Gy; mean right parotid dose (light green):11.4 Gy; mean left parotid dose (violet): 11.3 Gy; mean right (dark green) and left (pink) cochlea dose: 2 Gy; maximum mandibular dose (orange): 59.5 Gy; maximum spinal cord dose (light blue): 31.2 Gy. The radiation dose to these normal structures was well below the threshold for normal tissue damage and could potentially improve the patient quality of life after treatment. The red color illustrated radiation dose (70 Gy) to the gross tumor volume (gtv) while the dark blue and green color demonstrated radiation dose to the high risk area (63 Gy) and low risk area (56 Gy) respectively. The brown color illustrated radiation dose to the pharyngeal muscles which was high (mean 67 Gy) because of the close proximity to the gross tumor and may explain the high rate of dysphagia following radiotherapy for locally advanced laryngeal cancer.</p

Potential advantages and pitfalls of intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT) compared to 3-dimentional conformal radiotherapy (3-D CRT).

<p>Potential advantages and pitfalls of intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT) compared to 3-dimentional conformal radiotherapy (3-D CRT).</p

Dose distribution to target volume and to critical organs at risk for complications following image-guided radiotherapy for head and neck cancer.

<p>PTV1: target volume receiving 66 to 70 Gy; PTV2: target volume receiving 59.6 to 63 Gy; PTV3: target volume receiving 54 to 56 Gy; Gy: gray.</p

Dose distribution in Gray (Gy) to the larynx and other head and neck organs.

<p>TMJ: Temporo-mandibular joint.</p

Patient characteristics.

<p>IGRT: Image-guided radiotherapy; IMRT: Intensity-modulated radiotherapy.</p

Acute and late toxicities following intensity-modulated and image-guided radiotherapy for 27 patients with locally advanced laryngeal cancer.

<p>Acute and late toxicities following intensity-modulated and image-guided radiotherapy for 27 patients with locally advanced laryngeal cancer.</p

Illustrating the effectiveness of intensity-modulated and image-guided radiotherapy to achieve local control in T4 laryngeal cancer.

<p>The tumor invaded the thyroid cartilage and soft tissue of the neck and produced acute airway obstruction requiring emergency tracheostomy. A repeat CT scan at 40 Gy demonstrated significant shrinkage of the tumor allowing removal of the tracheostomy tube after treatment. The patient is disease-free 45 months after treatment and conserve a normal voice allowing him to work part-time after retirement.</p

Illustration of the effectiveness of Tomotherapy to deliver high radiation dose to the gross tumor and cervical lymph nodes while sparing adjacent normal structures.

<p>The patient had locally advanced base of the tongue cancer (T4) associated with massive cervical metastases (N3) and lung metastases at diagnosis. Following induction chemotherapy which resulted in resolution of the lung metastases, he had concurrent chemoradiation for local control and achieved a complete response of the gross tumor and lymph nodes on post-treatment PET-CT. The lung metastases recurred after treatment and were treated with adjuvant chemotherapy and consolidation stereotactic body radiotherapy. The patient is currently on remission two years after the treatment with no long-term complications except for xerostomia because of low radiation dose to the normal organs. The parotid glands could not be spared because of the close proximity to the gross lymph nodes and areas at high risk for disease.Red line: gross tumor and cervical lymph nodes treated to 70 Gy; green line: area at high risk for disease treated to 63 Gy; pink line: mandibular dose (mean: 56 Gy), gray line: pharyngeal muscles dose (mean: 33.6 Gy); gray-blue line: laryngeal dose (mean: 22.5 Gy); navy blue line: spinal cord dose (max: 39.4 Gy); light blue line: right cochlea dose: (mean: 4.5 Gy); light brown line: left cochlea dose: (mean: 5.3 Gy).</p