Radiotherapy for pediatric brain tumors: when and how.

Radiotherapy plays a central role in the treatment of pediatric brain tumors. Historically, surgical resection alone was the mainstay of treatment for pediatric CNS malignancies. During the past 75 years, radiotherapy has been incorporated into the upfront treatment of many pediatric brain tumors either as adjuvant therapy for resected tumors, definitive treatment for unresectable malignancies or as prophylactic therapy for occult microscopic disease. Many CNS malignancies, which were once universally fatal are now curable with multimodality approaches that integrate surgery, chemotherapy and radiotherapy. Unfortunately, the long-term CNS side effects of radiotherapy remain a major obstacle for survivors of childhood tumors. In this article we will discuss these issues in detail and summarize the ongoing efforts to reduce the risks of these toxicities.

Intensity-modulated radiotherapy for neoadjuvant treatment of gastric cancer.

Radiation therapy plays an integral role in the treatment of gastric cancer in the postsurgery setting, the inoperable/palliative setting, and, as in the case of the current report, in the setting of neoadjuvant therapy prior to surgery. Typically, anterior-posterior/posterior-anterior (AP/PA) or 3-field techniques are used. In this report, we explore the use of intensity-modulated radiotherapy (IMRT) treatment in a patient whose care was transferred to our institution after 3-field radiotherapy (RT) was given to a dose of 30 Gy at an outside institution. If the 3-field plan were continued to 50 Gy, the volume of irradiated liver receiving greater than 30 Gy would have been unacceptably high. To deliver the final 20 Gy, an opposed parallel AP/PA plan and an IMRT plan were compared to the initial 3-field technique for coverage of the target volume as well as dose to the kidneys, liver, small bowel, and spinal cord. Comparison of the 3 treatment techniques to deliver the final 20 Gy revealed reduced median and maximum dose to the whole kidney with the IMRT plan. For this 20-Gy boost, the volume of irradiated liver was lower for both the IMRT plan and the AP/PA plan vs. the 3-field plan. Comparing the IMRT boost plan to the AP/PA boost-dose range (<10 Gy) in comparison to the AP/PA plan; however, the IMRT plan irradiated a smaller liver volume within the higher dose region (>10 Gy) in comparison to the AP/PA plan. The IMRT boost plan also irradiated a smaller volume of the small bowel compared to both the 3-field plan and the AP/PA plan, and also delivered lower dose to the spinal cord in comparison to the AP/PA plan. Comparison of the composite plans revealed reduced dose to the whole kidney using IMRT. The V20 for the whole kidney volume for the composite IMRT plan was 30% compared to approximately 60% for the composite AP/PA plan. Overall, the dose to the liver receiving greater than 30 Gy was lower for the composite IMRT plan and was well below acceptable limits. In conclusion, our study suggests a dosimetric benefit of IMRT over conventional planning, and suggests an important role for IMRT in the neoadjuvant treatment of gastric cancer.

Review of current treatment practices for carcinoma of the head and neck.

The past two decades have witnessed a paradigm shift in the treatment of squamous cell carcinoma of the head and neck. Innovation in chemotherapy, radiotherapy and surgery has led to the assimilation of these modalities into our treatment algorithms. This modern multipart treatment plan has led to improved survival; however, this has come at the cost of increased toxicity. New and future therapies will be more tumour specific and, ideally, less toxic. Current research centres on these tumour-specific therapies with the anticipation of improved survival with decreased toxicity. This article will review the standard of care, recent advances and unfulfilled needs in the treatment of squamous cell carcinoma of the head and neck.