No abstract

The results of treatment of 48 patients with the diagnosis of chordoma during the period 1931 to 1981 at the Massachusetts General Hospital were reviewed. Fourteen patients were treated with surgery alone: eight patients with primary tumors in the sacrococcygeal region were treated with radical surgery and four are alive with no evidence of disease (NED) with follow-up of 8 to 20 years. Recurrent tumors in six patients were treated with surgery alone resulting in long palliation (3-25 years). The actuarial survival rate at 5 years for all patients treated with surgery was 76%. Radiation therapy was used in patients after either a biopsy (15), partial excision (17), or before radical excision in 2 patients. To achieve a worthwhile level of palliation, doses greater than 4000 cGy were required. High-dose levels (greater than 6500 cGy) were achieved in nine cases by a combination of photon and 160 MeV proton beams. The results to date of this approach for lesions of the base of skull and cervical vertebral body are encouraging: high local control and low morbidity. The 5-year actuarial survival rate of all patients treated with radiation was 50%.

Entamoeba histolytica is the responsible parasite of amoebiasis and remains one of the top three parasitic causes of mortality worldwide. With increased travel and emigration to developed countries, infection is becoming more common in nonendemic areas. Although the majority of individuals infected with E. histolytica remain asymptomatic, some present with amoebic colitis and disseminated disease. As more is learned about its pathogenesis and the host's immune response, the potential for developing a vaccine holds promise. This narrative review outlines the current knowledge regarding E. histolytica and E. dispar and insight in the development of a vaccine.

Sixty-eight patients with chordoma or low-grade chondrosarcoma at the base of the skull received fractionated high-dose postoperative radiation delivered with a 160-MeV proton beam. Protons have favorable physical characteristics which allow the delivery of high doses of radiation to these critically located tumors. The methods employed for these treatments are described. These patients have been followed for at least 17 months and for a median of 34 months. The median tumor dose was 69 CGE (cobalt Gy equivalent): CGE is the dose in proton Gy multiplied by 1.1, which is the relative biological effectiveness for protons compared to cobalt-60. The daily dose was 1.8 to 2.1 CGE. For this group the 5-year actuarial local control rate is 82% and disease-free survival rate is 76%. The incidence of treatment-related morbidity has been acceptable.