Chemotherapy is administered at prescribed doses and times.  Scheduling is important.  The intervals of infusions and in-between periods are called cycles.   The resting in-between periods allow the body to recover from the assault on healthy cells.  The resting period may only be a day or it may be several weeks.  Then a new cycle starts.  Several cycles after one another make up a course.  The course typically lasts six weeks to three months.

The most common regimen for solid cancer is dose-dense administration.  This page has more.

Pulse therapy

Also called intermittent therapy, this regimen employed a high dose of the chemotherapy drug followed by a rest period intended to allow the body to recover from side effects.  Pulse therapy is still used although it is giving way to dose-dense therapy.

Synchrony therapy

This is a type of combination regimen which tries to pull all the cancer cells into the same part of the mitosis cycle.  The first drug works on one part of the cell cycle, and ideally kills cells in that state.  The second drug then works in another part of the cell cycle.  After administration of both drugs, the remaining malignant cells are closer to being synchronized at the same point in the cell cycle.  This allows greater efficiency and specificity in the action of the second drug.

Recruitment therapy

This is a method that seeks to induce the cancer cells to divide so they can be attacked with a cell-cycle specific medicine.  It involves a combination of two drugs.  First a medicine that is not cell-cycle specific is administered in a high dose to kill a high percentage of the malignant cells.  In response, the remaining malignant cells that are interphase will move into mitosis to replenish the tumor population.

The cells are “recruited” to be at a place in the cycle where the second chemotherapy drug works.  Administration of the second drug is intended to kill most of the remaining malignant cells.

Rescue therapy

Rescue therapy is rarely used in oncology any more.  The term has a specific meaning when applied to cancer treatment.  Although something incorrectly used to refer to “last ditch” treatment of patients with very dire metastatic cancer – this is more properly called salvage therapy today – the original meaning of rescue therapy referred to a form of a combination regimen.  Rescue therapy was when an initial agent was given at a high dose – higher than would normally be employed – to kill cells and then following up with another drug to rescue the non-malignant cells.  This second drug works only on the non-cancerous cells.  The net effect is that the cancer cells are left to die while the good cells recover.  A regimen used in rescue therapy was methotrexate followed by leucovorin.

See also: metronomic chemotherapy.

Consolidation Chemotherapy

Consolidation chemotherapy is when the patient gets chemotherapy treatment after the primary treatment has been successful.  If the cancer is in remission or no cancer can be detected any more, doctors sometimes deem it useful to give another course of drug treatment to ensure traces of the malignancy are stamped out.  Although often used to treat leukemia, consolidation chemotherapy also finds use in treatment of other cancers.  It is also called intensification therapy or postremission therapy.

In leukemia treatment consolidation chemotherapy is often split into two sequential phases.  In phase I, the treatment phase, the patient receives medicine every day for 5 days.  Phase II is the recovery phase, lasting three to four weeks.  No chemotherapy agents are given during this period, but the medical team monitors the patient’s health, including blood health metrics.  Infusions of blood or blood products are often done during this period.

Time Series – Long-term Course of Chemotherapy

Oncologists consider each patient and develop a treatment plan.  The long-term plan is flexible and subject to change as the patient responds to treatment.  The plan may call for several courses of chemotherapy over the course of months or years.  A common sequence is induction therapy followed by consolidation therapy followed by maintenance therapy.

Maintenance therapy is a longer term, lower dosage course intended to prevent a recurrence of the cancer.