Task: Text to Code
Input (English): Step 1: For each row in Treatment_Types table, find the corresponding rows in Treatments table.
Step 2: find the number of rows of each value of Treatments's treatment_type_code in the results of step 1.
Step 3: find treatment_type_description of step 1 results with smallest value in the results of step 2
Output (English): SELECT T1.treatment_type_description FROM Treatment_Types AS T1 JOIN Treatments AS T2 ON T1.treatment_type_code = T2.treatment_type_code GROUP BY T2.treatment_type_code ORDER BY Count ( * ) Asc LIMIT 1