A-Z of Stem Cell Transplantation, Cellular Therapies & Bone Marrow Recovery Terms

​​

Apheresis

Apheresis is a medical procedure used to collect stem cells from the bloodstream before a stem cell transplant. During the procedure, blood is removed from the body, stem cells are separated and collected, and the remaining blood components are returned to the patient. Apheresis is commonly used when preparing for an autologous stem cell transplant in children with relapsed or high-risk Wilms tumor.

​

Autologous Stem Cell Transplant

An Autologous Stem Cell Transplant (ASCT) is a procedure in which a patient's own stem cells are collected, stored, and later returned following high-dose chemotherapy. The transplant helps restore bone marrow function after intensive treatment has destroyed both cancer cells and healthy blood-forming cells. Autologous transplantation may be considered for selected children with relapsed or high-risk Wilms tumor.

 

Bone Marrow

Bone marrow is the soft, spongy tissue found inside bones where blood cells are produced. Bone marrow generates red blood cells, white blood cells, and platelets that are essential for oxygen transport, infection prevention, and blood clotting. High-dose chemotherapy can temporarily damage bone marrow, making stem cell support necessary in some treatment situations.

 

Bone Marrow Failure

Bone marrow failure occurs when the bone marrow is unable to produce sufficient healthy blood cells. This may result from intensive chemotherapy, radiation therapy, infection, or other medical conditions. Stem cell transplantation helps restore blood cell production following treatment-related bone marrow suppression.

 

Bone Marrow Recovery

Bone marrow recovery is the process by which blood cell production returns after chemotherapy, radiation therapy, or stem cell transplantation. Recovery is monitored through regular blood tests and clinical assessments. Successful bone marrow recovery is essential for restoring immune function and overall health.

​

Cellular Therapy

Cellular therapy refers to medical treatments that use living cells to treat disease. In pediatric oncology, stem cell transplantation is one of the most established forms of cellular therapy. Emerging cellular therapies continue to be investigated as researchers explore new approaches to treating childhood cancers.

​

Conditioning Regimen

A conditioning regimen is the intensive chemotherapy, and sometimes radiation therapy, administered before a stem cell transplant. The purpose is to destroy remaining cancer cells and prepare the bone marrow for stem cell infusion. Conditioning regimens vary depending on the disease being treated and the transplant approach used.

​

Cryopreservation

Cryopreservation is the process of freezing and storing stem cells at extremely low temperatures until they are needed for transplantation. Collected stem cells can remain safely stored for extended periods before being thawed and returned to the patient following high-dose treatment.

​

Engraftment

Engraftment occurs when transplanted stem cells successfully settle within the bone marrow and begin producing healthy blood cells. Engraftment is one of the most important milestones following stem cell transplantation and is closely monitored through laboratory testing and clinical evaluation.

​

Growth Factor Support

Growth factor support involves medications that stimulate the bone marrow to produce white blood cells more rapidly. These medications are often used following chemotherapy or stem cell transplantation to reduce infection risk and accelerate recovery of the immune system.

​

Hematopoietic Stem Cell

A Hematopoietic Stem Cell (HSC) is a specialized cell capable of developing into all types of blood cells. These cells form the foundation of stem cell transplantation and play a critical role in restoring blood cell production following intensive cancer treatment.

​

Hematopoietic Stem Cell Transplantation (HSCT)

Hematopoietic Stem Cell Transplantation (HSCT) is a medical procedure that replaces damaged or destroyed blood-forming cells with healthy stem cells. HSCT may be used in selected cases of relapsed or very high-risk Wilms tumor when intensive chemotherapy is required.

​

High-Dose Chemotherapy

High-dose chemotherapy involves administering larger-than-standard doses of anti-cancer drugs to maximize cancer cell destruction. Because these treatments can severely affect bone marrow function, stem cell transplantation is often required to restore blood cell production afterward. High-dose chemotherapy is most commonly used in selected relapse settings.

​

Immune Recovery

Immune recovery refers to the restoration of normal immune system function following chemotherapy or stem cell transplantation. During recovery, children remain vulnerable to infections and require careful monitoring, preventive measures, and supportive care until immune function normalizes.

​

Infused Stem Cells

Infused stem cells are the stem cells returned to a patient following completion of high-dose treatment. The cells travel through the bloodstream to the bone marrow, where they establish themselves and begin producing healthy blood cells.

​

Mobilization

Mobilization is the process of stimulating stem cells to move from the bone marrow into the bloodstream so they can be collected through apheresis. Growth factor medications are often used to improve stem cell collection success.

​

Peripheral Blood Stem Cells (PBSC)

Peripheral Blood Stem Cells (PBSC) are stem cells collected directly from the bloodstream rather than from the bone marrow. PBSC collection has become the most common method of obtaining stem cells for autologous transplantation because it is generally less invasive than bone marrow harvesting.

​

Platelet Recovery

Platelet recovery refers to the restoration of healthy platelet levels following chemotherapy or stem cell transplantation. Platelets play a critical role in blood clotting, and recovery is monitored carefully because low platelet counts can increase bleeding risk.

 

Relapsed Wilms Tumor Transplant Therapy

In selected cases of relapsed Wilms tumor, stem cell transplantation may be considered as part of an intensive treatment strategy following salvage chemotherapy. The goal is to improve disease control and increase the likelihood of achieving long-term remission in children with recurrent disease.

 

Salvage Transplant

A salvage transplant is a stem cell transplant performed after standard treatments have failed or following cancer relapse. Salvage transplants are generally reserved for highly selected patients and are often combined with intensive chemotherapy regimens.

 

Stem Cell Collection

Stem cell collection is the process of harvesting stem cells from the bloodstream or bone marrow before transplantation. Collection usually occurs after mobilization and before high-dose chemotherapy begins. The collected cells are frozen and stored until they are needed.

 

Stem Cell Infusion

A stem cell infusion is the process of returning previously collected stem cells to the patient following high-dose treatment. The procedure resembles a blood transfusion and allows stem cells to travel back to the bone marrow where they can begin producing healthy blood cells.

 

Stem Cell Rescue

Stem cell rescue refers to the reinfusion of stem cells following high-dose chemotherapy. The rescue process restores bone marrow function and allows blood cell production to recover after intensive treatment has been completed.

 

Stem Cell Transplant

A stem cell transplant is a procedure used to replace damaged blood-forming cells following intensive cancer treatment. Although not routinely required for most Wilms tumor patients, stem cell transplantation may be considered for selected children with relapsed, recurrent, or very high-risk disease.

 

Supportive Care During Transplant

Supportive care during transplant includes infection prevention, nutritional support, blood transfusions, symptom management, hydration, and close medical monitoring. Supportive care is essential because children undergoing stem cell transplantation experience significant temporary suppression of the immune system and bone marrow.

​

Total Body Irradiation (TBI)

Total Body Irradiation (TBI) is a form of radiation therapy that exposes the entire body to radiation before stem cell transplantation. TBI is not routinely used in Wilms tumor treatment but may occasionally be incorporated into specialized transplant protocols or research settings.

 

Transplant Center

A transplant center is a specialized healthcare facility with expertise in stem cell transplantation and advanced cancer care. These centers provide multidisciplinary services including transplant physicians, nurses, pharmacists, psychologists, dietitians, and rehabilitation specialists who support patients throughout the transplant process.

 

White Blood Cell Recovery

White blood cell recovery refers to the restoration of infection-fighting immune cells following chemotherapy or stem cell transplantation. Recovery is monitored through blood testing because adequate white blood cell counts are essential for protecting patients from serious infections.

 

Very High-Risk Wilms Tumor

Very high-risk Wilms tumor refers to aggressive disease that may involve multiple relapses, treatment resistance, unfavorable biological features, or poor response to conventional therapies. In selected circumstances, stem cell transplantation may be considered as part of an intensive treatment strategy for these patients.