Patterns of care study of radiation therapy for esophageal cancer in Japan: Influence of the stratification of institution on the process

Background: To improve the quality of radiation therapy in Japan, Patterns of Care Study (PCS), a widely known QA program in the USA, was introduced in Japan. The feasibility was tested by collecting nationwide data by extramural audit for esophageal cancer. Methods: From July 1996 through February 1997, PCS audits were performed for 29 institutions. Based on the facility survey by Tsunemoto, 13 institutes were classified as A1 (university hospital/cancer center treating >300 patients/year), 10 as B1 (other institutes >120 patients/year) and six as B2 (other institutes <120 patients/year). Medical charts for 455 patients with thoracic esophageal cancer between 1992 and 1994 were reviewed based on the data format of PCS in the USA. Results: Concerning external beam equipment, linear accelerators of greater than or equal to 10 MV were used for 73% of patients in A1, whereas in B1-2, Co-60 machines were still used for 13% of patients (P < 0.0001). The median number of full-time equivalent (FTE) radiation oncologists was 2.7 in A1, 0.65 in B1 and 0.2 in B2. Forty-five percent of patients had received surgery in A1 and 34% in B1-2 (P = 0.0068), In the non-surgery group, a higher radiation dose of >60 Gy was delivered in A1 than in B1-2 (P = 0.0008). Chemotherapy was administered to 51% of the patients in Al and to 30% in B1-2 (P < 0.0001). Brachytherapy was utilized for 17% in A1 and only for 5% in B1-2 (P = 0.0001). Conclusion: Institutional stratification, including equipment and personnel, significantly affected the patterns of care for esophageal cancer. Therefore, to improve the quality of radiation therapy nationwide, improvement of equipment and supply of FTE personnel is extremely important. PCS was found to have great potential for the practical evaluation of how much will be required in Japan.