Hirohiko Tsujii

The value of treatment planning using CT and an immobilizing shell in radiotherapy for paranasal sinus carcinomas

This article describes a method which uses CT scans and immobilizing shells radiation treatment planning (CT-assisted planning) for paranasal sinus carcinomas and the value of this method on the treatment outcome. Results of the treatment for 82 patients who had CT-assisted planning were compared with that of 88 patients who had no such treatment planning. It has been concluded that the combined use of CT and the shell in treatment planning permitted a 3-dimensional localization of both the tumor and critical normal structures with great accuracy, leading to an improved long-term survival and a reduced complication rate. The multivariate regression analysis for predicting significant prognostic factors also confirmed the valuable role of CT in terms of survival and primary tumor control. The actuarial 5-year survival rate was 51% in all patients, whereas, by using CT-assisted planning, it was improved to 61%. The improved survival was observed among the patients with tumors of the suprastructures where tumors were located adjacent to the critical organs (brain and eye). Major complications attributable to radiation have included instances of brain and ocular damage. CT-assisted planning, however, has been proven effective in avoiding brain necrosis and preserving eye sight.

Early stage head and neck non-Hodgkin's lymphoma: the effect of tumor burden on prognosis

Treatment results were investigated in 113 previously untreated patients with clinical Stage I and II (Ann Arbor) non‐Hodgkins lymphoma of the head and neck. Fifty‐six Waldeyers ring, 34 other extranodal sites, and 23 cervical nodal lesions were included. The overall relapse‐free survival at 5 years was 41%. Age and Ann Arbor stage influenced relapse‐free survival. The results suggested that the tumor cell burden is a fundamental prognostic factor for patients with Waldeyers ring disease and for patients with only cervical nodal disease. Abdominal relapse was most frequent, followed by generalized relapse. From 1981, patients were randomized in a clinical trial to receive either chemotherapy (cyclophosphamide, vincristine, and prednisone [CVP], five courses) or whole‐abdominal irradiation (25 Gy/20 Fr) as an adjuvant therapy. Patients could not tolerate the whole‐abdominal irradiation well. A significant improvement in survival has been obtained by adjuvant chemotherapy.

Future Directions of Proton Beam Radiotherapy for Bone and Soft Tissue Tumors

Bone and soft tissue tumors frequently recur locally when treated with surgery alone. Therefore, in an effort to improve treatment outcome, combined surgery and radiotherapy has been advocated as an effective modality. However, with conventional radiation, these tumors can usually be given only a moderate dose of radiation with the result that most recur locally. In this regard, proton beam radiotherapy offers potential advantages with respect to dose distribution characterized by Bragg-peak formation, which allows precise delivery of high radiation doses to a tumor while avoiding irradiation to adjacent normal tissues [1, 2].