Fill in the blanks with the missing words: 20) The use of radioactive substances in the treatment of cancer is called _________________. 21) _____...

Fill in the blanks with the missing words:

20) The use of radioactive substances in the treatment of cancer is called _________________.
21) _________________________ can be divided into beta minus (emission of an electron) and beta plus (emission of a positron).
22) ______________________ is the radioisotope most commonly used to label molecules used in SPECT.
23) ______________________________ is a Nuclear Medicine imaging modality based on the fusion of scintigraphy with tomography, which uses positron-emitting radionuclides (β+).
24) ______________________ is the radioisotope most commonly used in PET.
a) chemotherapy, radiotherapy, iodine-131, PET, beta radiation
b) radiotherapy, chemotherapy, iodine-123, SPECT, gamma radiation
c) radiotherapy, chemotherapy, iodine-131, PET, gamma radiation
d) radiotherapy, chemotherapy, iodine-123, PET, beta radiation