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

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

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

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

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

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

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