Purpose: High-energy heavy ions generated by accelerators utilized in industrial and medical uses. Ar, C, and He heavy ions have been used in the treatment of cancer. In this research, it was tried to calculate the radioactive elements production in healthy tissues around tumors by heavy ions spallation process in the direct usage of high-energy ions for the treatment of cancerous tumors. Materials and Methods: The radioactive elements production in body tissues irradiated with heavy ions was calculated by Monte Carlo N Particle X-version (MCNPX) code based on the Monte Carlo method. The F8 tally card with FT8 command was utilized to derive the activation and spallation data in the range of Z1 to Z2 atomic numbers. Results: A wide range of radioactive elements was created in healthful tissues in Ne, C, Ar, and He heavy ions therapy. Results show that 10Be,14C, 26Al, 36Cl, 39Ar, 40K, 39Ar, 32Si, 22Na, and 36Cl radioactive materials were produced for high-energy heavy ions spallation in healthy soft tissue. Conclusion: The results of this research show that due to using directly high-energy ions to treat internal tumors, healthy soft tissue is activated. Also, by irradiated Ne, C, Ar, and He ions, the radioactive elements are produced with high gains and long half-lives. Therefore, in the therapy of cancerous tumors with high-energy ions, due to the production of radioactive agents, healthy tissues are at high risk.