Convert Repeating Fields (Columns) to Rows

I have an Excel problem that I hope someone can help me resolve. I have an Excel data export from a clinical radiation system. There is one row per patient in the export and each patient could have received one or more radation treatments.

The problem I have is that there is one horizontal row for each patient regardless of how many treatments they recived. The fields are repeated in that row with an appended number (A1_1, A1_2, A1_3
...) for each successive treatment. The first 2 fields are not repeated - SubjID and ProtocolID.

What I would like to do is have a seperate row (record) for each time there is a new treatment for a patient. The SubjID and ProtocolID would always be the same for each unique patient.

So the question what can I do to put all that horizontal data into individual rows?

Sample Excel column structure:

SubjID, ProtocolID, RadiationType_A1_1, TSSPatientID_A1_1, TotalDose_A1_1, RadiationType_A1_2, TSSPatientID_A1_2, TotalNoFractions_A1_2, RadiationType_A1_3, TSSPatientID_A1_3, TotalNoFractions_A1_3,

Thanks for any suggestions you may have,
Ken