No, it isn't

First of all, a teaspoon of Baking Soda contains between 1100 and 1300 mg of Sodium.  Secondly, baking soda can raise blood pressure.  And third, there is the issue of maintaining a steady blood pH. From Cancertutor.com:

The real issue is getting the baking soda past the digestive tract. (When baking soda is injected) This creates a localized area of the body which has a high concentration of baking soda. It is an effective treatment.

. . . . getting the baking soda past the digestive tract does not create a localized area of high concentrations of baking soda.

It is NOT advisable to create a wide area of a high concentration of baking soda because the blood must remain at a constant pH.

Furthermore, human blood already contains some baking soda. The baking soda acts as a buffer for acids.

Human blood must remain at a constant pH or else the person may die. It is not wise to tamper with this pH. Baking soda already in the blood is used by the body to keep the blood from becoming too acidic.

Some have suggested that the combination of baking soda and maple syrup in the stomach creates carbon dioxide which is helpful in treating cancer.

The fact is that carbon dioxide is present throughout your body. Every cell in the body excretes carbon dioxide. The blood carries this carbon dioxide to the lungs where it is discharged when you breathe.

Claiming that adding carbon dioxide to the body is good is like saying that taking a shower outside, during a thunderstorm, is good.

In short, this treatment is not in any way endorsed or supported by the Cancer Tutor website.