Re-irradiation for Recurrent Head and Neck Cancer

After radical treatment of head and neck cancer about 20–50% of patients are diagnosed with the locoregional recurrence during first two years. The main treatment for recurrent disease is salvage surgery, but in most cases, surgery is not feasible due to the high risk of complications and morbidity, and only 20% of patients are suitable for surgical salvage. Reirradiation is an effective treatment method with acceptable toxicity, but this treatment method is limited to normal tissue tolerance to a total dose. When chemotherapy is administered for recurrence, the response rate is up to 40%, so with the advancement of technical measures, after introduction of intensity‐modulated radiotherapy, fractionated stereotactic body radiation therapy, high‐dose‐rate brachytherapy, proton beam reirradiation, a reirradiation is increasingly more often used for head and neck cancer relapse treatment. In this chapter, we will discuss about reirradiation with curative intent using new different radiation techniques (intensity‐modulated radiotherapy (IMRT), stereotactic body radiation therapy (SBRT), high‐dose‐rate brachytherapy (HDR‐BRT) and proton beam reirradiation (PBRT) for previously irradiated head and neck cancer and present recommendations for retreatment of head and neck cancer relapse using reirradiation alone or with systemic chemotherapy/biologic therapy

The Role of Radiology and Radiotherapy for Multiple Myeloma

Skeletal-related events occur in 80% of patients with multiple myeloma (MM). Osteoporosis, osteoclastic destructions, pathological fractures of the bone, spinal cord and compression can impair patients’ quality of life and reduce survival. Many imaging techniques can be used for the detection of MM bone lesions. Many clinical studies suggest modern imaging techniques for their greater sensitivity. Radiotherapy is a treatment of choice for solitary plasmacytoma of the bone and extramedullary plasmacytomas. However, radiation treatment of MM can be used as a palliative approach for uncontrolled pain, impending pathological fractures and in the cases of spinal cord compression. Radiotherapy induces analgesic effect in 75–100% of patients and promotes a recalcification in 40–60%. In patients with spinal cord compression, radiation therapy is given along with dexamethasone, and up to half of patients may experience improvement. It is well known that pain perception, response to analgesics and pain relief effect of radiotherapy are quite different for multiple myeloma patients. Clinical, laboratory and genetic factors may influence the pain perception and analgesic effect of radiotherapy. Side effects of radiation are generally mild, are limited to the radiotherapy site and can be predicted

Application of 3D Gel Dosimetry as a Quality Assurance Tool in Functional Leksell Gamma Knife Radiosurgery

Highly precise dose delivery to the target (tumor or cancerous tissue) is a key point when brain diseases are treated applying recent stereotactic techniques: intensity-modulated, image-guided radiotherapy, volumetric modulated arc therapy, Gamma knife radiosurgery. The doses in one single shot may vary between tens and hundreds of Gy and cause significant cell/tissue/organ damages. This indicates the need for implementation of quality assurance (QA) measures which are realized performing treatment dose verification with more than one calibrated quality assurance method or tool, especially when functional radiosurgery with a high dose (up to 40 Gy in our case) shall be delivered to the target using small 4 mm collimator. Application of two dosimetry methods: radiochromic film dosimetry using RTQA2 and EBT3 films and dose gel dosimetry using modified nPAG polymer gels for quality assurance purposes in stereotactic radiosurgery treatments using Leksell Gamma Knife© Icon™ facility is discussed in this paper. It is shown that due to their polymerization ability upon irradiation nPAG gels might be potentially used as a quality assurance tool in Gamma knife radiosurgery: they indicate well pronounced linear dose response in hypo-fractionated (up to 10 Gy) dose range and are sensitive enough to irradiation dose changes with a high (at least 0.2 mm) spatial resolution. Dose assessment sensitivity of gels depends on parameters of a dose evaluation method (optical or magnetic resonance imaging), however, is similar to this estimated using film dosimetry, which is set as a standard dosimetry method for dose verification in radiotherapy