Potential requirement of positron emission tomography apparatuses in Asia and latin america including Mexico.

The number of positron emission tomography (PET) machines has been increasing in regions of East-, Southeast-, and South-Asia as well as in Latin America including Mexico. This study was performed to assess the potential requirement of PET machines in 19 countries which already use PET in the aforementioned regions. Data on the number of PET machines and internationally available characteristics of the restrictive countries such as the land area, the total population, the gross national income (GNI), and the average life span of inhabitants were obtained from IAEA, UN, WB, and WHO. Correlation between the number of PET machines and the characteristics of each country was evaluated. The potentially required number of PET machines, which was obtained by adjusting the number of PET machines with statistically significant, correlative characteristics of each country, standardized on the state of Japan, were compared. The number of PET machines could be significantly correlated to the GNI of a country and the average life span of its inhabitants (P < 0.05). Based on Japan, most of the countries in the regions would require considerably more PET machines. With installation of the potentially required number of PET machines in each of the countries, the number of PET machine per 10(6) population would increase by 1.1- to 12-fold, in comparison with the current situation. With regards to the potentially required number of PET machines, most of the countries in these regions may require a considerable increase of PET machines. Nevertheless, some countries in the Asia seem to require outside assistance such as international support in order to introduce PET and enhance the efficacy of their health services.

Introduction

A noticeable change in the causes of mortality and mobility has occurred globally. Nowadays, cancer is a major cause of mortality.[1] Changing lifestyles, increasing life expectancies, and a corresponding increase of an aging population are drawing emerging countries closer to developed countries in the matter of health problems.[1] In concordance with these changes, nuclear medicine practice has developed through remarkable advances in instrumentation as well as in information technology. The novel technology of positron emission tomography (PET) has reinvigorated the service of nuclear medicine in medical management. In particular, hybrid imaging equipment such as PET/CT has provided a valuable momentum for diagnostic and therapeutic applications for cancer.[12]

Practice of nuclear medicine has shown both heterogeneous and homogeneous trends around the world during the past decade.[1] The use of PET is increasing markedly in Asia and moderately in Latin America.[1] On the other hand, the increase in therapeutic applications of nuclear medicine indicates some degree of homogeneity worldwide.[1]

This article aims at assessing the number of PET machines being potentially required in countries in the regions of East-, Southeast-, and South-Asia and Latin America including Mexico, using Japan as standard.

Materials and Methods

Data collection

Data on the number of PET machines in Japan (JPN), Republic of Korea (ROK), People's Republic of China (CHN), India (IND), Malaysia (MAL), Socialist Republic of Viet Nam (VIE), Republic of the Philippines (PHI), People's Republic of Bangladesh (BGD), Islamic Republic of Pakistan (PAK), Taiwan (ROC-TW), Kingdom of Thailand (THA), Republic of Singapore (SNG), Republic of Indonesia (IDN), United Mexican States (MEX), Argentine Republic (ARG), Oriental Republic of Uruguay (URU), Republic of Colombia (COL), Republic of Chile (CHL), Federative Republic of Brazil (BRA), and Bolivian Republic of Venezuela (VEN) were made available during the International Conference on Clinical PET and Molecular Nuclear Medicine which was organized in Vienna, Austria by the International Atomic Energy Agency from 8 to 11 November 2011.[3] Internationally available characteristics of countries such as the land area, the total population, the gross national income (GNI), and the average life span of inhabitants were obtained from the United Nations, the World Bank, and World Health Organization (WHO).[4-6] The collected data are summarized in Table 1.

Table 1

Amount of PET systems, cyclotrons and characteristics of countries in east-, southeast- and South-Asia and latin America with Mexico

Correlation analysis

The number of PET machines were correlated with the characteristics of the respective countries. The correlation was described with the Spearman correlation coefficient. A value of P < 0.05 was considered statistically significant.

Assessing potentially required number of PET machines

The number of PET machines in each country was adjusted with statistically significant correlative characteristics of each country, standardized on the state of Japan. Thus, the potentially required number of PET machines was calculated. A fill-rate (%) was then calculated as the number of PET machines divided with the potentially required number of PET machines in a country. The number of PET machines per 106 population before and after adjustment were calculated in each country.

Results

The Spearman correlation coefficient using the number of PET machines in countries was strong for the GNI (0.879, P = 3.17 × 10−7) and weak for the average life span of inhabitants (0.446, P = 0.0489) [Figure 1]. There was no correlation of the number of PET apparatuses in countries with the land area (0.0999, P = 0.675) or the total population of inhabitants (0.173, P = 0.416) [Figure 1]. The number of PET machines in each country was therefore adjusted with the GNI and the average life span, based on the state of Japan. They are summarized as potentially required number of PET machines in Table 2. Based on the state of Japan, IND, ROC-TW, ARG, and URU reach over 60% of the required number of PET machines while ROK already attained 153% [Figure 2]. However, other countries in the regions fall significantly short of the potentially required number of PET machines. The number of PET machines per 106 population before and after adjustment in each country are demonstrated in Figure 3. With the installation of the potentially required number of PET apparatuses in each of the countries, the number of PET machines per 106 population would increase by 1.1- to 12-fold, in comparison with the current situation.

Figure 1

Correlation of the number of PET machines in countries in East-, Southeast-and South-Asia and Latin America with Mexico with the characteristics of the respective counties. There is a strong and weak correlation of the number of PET apparatuses in countries with the GNI (c) and the average life span of inhabitants (d) in the respective countries. There is no correlation between the number of PET machines and the land area (a) or the total population of inhabitants (b) in the respective countries

Table 2

Adjusted number of PET machines with GNI and average life sSpan in countries in East-, Southeastand South-Asia and Latin America with Mexico

Figure 2

Fill-rates of PET apparatus in the respective countries in East-, Southeast-and South-Asia and Latin America with Mexico. A fill-rate (%) was calculated as the number of PET machines divided with the potentially required number of PET machines in each country. Standardized on the state of Japan, they vary from 8 to 153%

Figure 3

The number PET machines per 106 population before and after adjustment with economical and healthcare indices in the respective countries. The number of PET apparatuses per 106 population may increase by 1.1 to 12 folds by installation of potentially required number of PET machines

Discussion

We tried to assess the potentially required number of PET machines in the countries through an International comparison approach. The assessment was based on economic and healthcare indices which were in relationship with the number of PET machines. Though Japan might not be ideal for the situation of PET utilization, it was supposed to be a basis for comparison because of one of the countries in which PET services have been available early on and lots of knowledge and experience on PET applications in health care have been archived. It is known that gross domestic product (GDP) and GNI are not perfectly satisfactory measures of growth; or reflection of an economical index in order to evaluate how well-off a country is. However, it is recognized that a profusion of PET machines may be relevant to the economic power of a country; since it has been noted that there is a strong positive correlation between the number of PET machines in a country with considerable foreign currency reserve as determined by Spearman correlation co-efficient (0.614, P = 3.99 × 10−3). Therefore, GNI was employed as an economic index for the international comparison approach.

The collected data on PET machines includes both stand-alone PET and hybrid PET/CT. Installations of hybrid PET/CT systems have surpassed those of stand-alone PET. In the regions of Asia and Latin America, percentages of stand-alone PET apparatus vary from 15 to 20% of the total number of PET apparatus.[2] The prevalence of stand-alone PET machines in individual countries is strongly linked to the timing of PET installation, with countries that have only recently implemented PET, having PET/CT almost exclusively.[12] The developing and semi-developed countries in the East-, Southeast-, and South-Asia and Latin America including Mexico mainly use hybrid PET/CT machines.

Most PET apparatuses are owned by the United States and Japan.[12] Though China is third in the Asian region as regards the number of PET machines, the potentially required number of PET machines is thought to be 356 units. In this case, the number of PET machines per 106 population could be 0.26. On the other hand, in BGD the potentially required number of PET machines is 7 units and the number of PET machines per 106 population could be 0.04. Each country in these regions is thought to be expanding the practice of PET using their own resources according to the strong correlation of the number of PET machines to the economic factor of GNI. Nevertheless, BGD, VIE, PAK, and IND might require international support due to economical limitation in case of installing more PET machines to raise the number of PET machines per 106 population.

Conclusion

The number of PET machines has been increasing in the regions of East-, Southeast- and South-Asia, and Latin America including Mexico. With regards to the required number of PET machines, most of the countries in these regions require a considerable increase of PET apparatuses. Each country in these regions may be thought to be expanding the practice of PET using their own resources. However, some countries in the Asia seem to require outside assistance such as international support in order to efficiently perform practice of PET in medical management.