Billing CPT 80101 vs. G0340

Which of these codes should be utilized currently for Pain Management billing and how does this relate to the billing of the number of units?

who ordered and why. Do not understand question

Stereotactic Body Radiation Therapy (SBRT) is a treatment that couples a high degree of anatomic targeting accuracy and reproducibility with very high doses of extremely precise, externally generated, ionizing radiation, thereby maximizing the cell-killing effect on the target(s) while minimizing radiation-related injury in adjacent normal tissues.
G0340
Image-guided robotic linear accelerator-based stereotactic radiosurgery, delivery including collimator changes and custom plugging, fractionated treatment, all lesions, per session, second through fifth sessions, maximum five sessions per course of treatment (for use in hospital-based facilities (OPPS) and ASCs only).

From January 1, 2010 through March 31, 2010, when performing a qualitative drug screening test for a single class of drugs, regardless of the testing methodology, those clinical laboratories that do not require a CLIA certificate of waiver should bill new test code G0431. Those clinical laboratories that do require a CLIA certificate of waiver should continue to utilize CPT Code 80101QW.