Toxicities of total-body irradiation for pediatric bone marrow transplantation

Kidney Disease in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

Kidney injury is a known late and potentially devastating complication of abdominal radiation therapy (RT) in pediatric patients. A comprehensive Pediatric Normal Tissue Effects in the Clinic review by the Genitourinary (GU) Task Force aimed to describe RT dose-volume relationships for GU dysfunction, including kidney, bladder, and hypertension, for pediatric malignancies. The effect of chemotherapy was also considered.

METHODS AND MATERIALS

We conducted a comprehensive PubMed search of peer-reviewed manuscripts published from 1990 to 2017 for investigations on RT-associated GU toxicities in children treated for cancer. We retrieved 3271 articles with 100 fulfilling criteria for full review, 24 with RT dose data and 13 adequate for modeling. Endpoints were heterogenous and grouped according to National Kidney Foundation: grade ≥1, grade ≥2, and grade ≥3. We modeled whole kidney exposure from total body irradiation (TBI) for hematopoietic stem cell transplant and whole abdominal irradiation (WAI) for patients with Wilms tumor. Partial kidney tolerance was modeled from a single publication from 2021 after the comprehensive review revealed no usable partial kidney data. Inadequate data existed for analysis of bladder RT-associated toxicities.

RESULTS

The 13 reports with long-term GU outcomes suitable for modeling included 4 on WAI for Wilms tumor, 8 on TBI, and 1 for partial renal RT exposure. These reports evaluated a total of 1191 pediatric patients, including: WAI 86, TBI 666, and 439 partial kidney. The age range at the time of RT was 1 month to 18 years with medians of 2 to 11 years in the various reports. In our whole kidney analysis we were unable to include chemotherapy because of the heterogeneity of regimens and paucity of data. Age-specific toxicity data were also unavailable. Wilms studies occurred from 1968 to 2011 with mean follow-ups 8 to 15 years. TBI studies occurred from 1969 to 2004 with mean follow-ups of 4 months to 16 years. We modeled risk of dysfunction by RT dose and grade of toxicity. Normal tissue complication rates ≥5%, expressed as equivalent doses, 2 Gy/fx for whole kidney exposures occurred at 8.5, 10.2, and 14.5 Gy for National Kidney Foundation grades ≥1, ≥2, and ≥3, respectively. Conventional Wilms WAI of 10.5 Gy in 6 fx had risks of ≥grade 2 toxicity 4% and ≥grade 3 toxicity 1%. For fractionated 12 Gy TBI, those risks were 8% and <3%, respectively. Data did not support whole kidney modeling with chemotherapy. Partial kidney modeling from 439 survivors who received RT (median age, 7.3 years) demonstrated 5 or 10 Gy to 100% kidney gave a <5% risk of grades 3 to 5 toxicity with 1500 mg/m2 carboplatin or no chemo. With 480 mg/m2 cisplatin, a 3% risk of ≥grade 3 toxicity occurred without RT and a 5% risk when 26% kidney received ≥10 Gy. With 63 g/m2 of ifosfamide, a 5% risk of ≥grade 3 toxicity occurred with no RT, and a 10% toxicity risk occurred when 42% kidney received ≥10 Gy.

CONCLUSIONS

In patients with Wilms tumor, the risk of toxicity from 10.5 Gy of WAI is low. For 12 Gy fractionated TBI with various mixtures of chemotherapy, the risk of severe toxicity is low, but low-grade toxicity is not uncommon. Partial kidney data are limited and toxicity is associated heavily with the use of nephrotoxic chemotherapeutic agents. Our efforts demonstrate the need for improved data gathering, systematic follow-up, and reporting in future clinical studies. Current radiation dose used for Wilms tumor and TBI appear to be safe; however, efforts in effective kidney-sparing TBI and WAI regimens may reduce the risks of renal injury without compromising cure.

Liver Late Effects in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

A pediatric normal tissue effects in the clinic (PENTEC) comprehensive review of patients with childhood cancer who received radiation therapy (RT) to the liver was performed to develop models that may inform RT dose constraints for the liver and improve risk forecasting of toxicities.

METHODS AND MATERIALS

A systematic literature search was performed to identify published data on hepatic toxicities in children. Treatment and outcome data were extracted and used to generate normal tissue complication probability (NTCP) models. Complications from both whole and partial liver irradiation were considered. For whole liver irradiation, total body irradiation and non-total body irradiation treatments were considered, but it was assumed that the entire liver received the prescribed dose. For partial liver irradiation, only Wilms tumor flank field RT could be analyzed. However, a prescribed dose assumption could not be applied, and there was a paucity of analyzable liver dosimetry data. To associate the dose-volume exposures with the partial volume complication data from flank irradiation, liver dose-volume metrics were reconstructed for Wilms tumor flank RT using age-specific computational phantoms as a function of field laterality and superior extent of the field.

RESULTS

The literature search identified 2103 investigations pertaining to hepatic sinusoidal obstructive syndrome (SOS) and liver failure in pediatric patients. All abstracts were screened, and 241 articles were reviewed in full by the study team. A model was developed to calculate the risk of developing SOS after whole liver RT. RT dose (P = .006) and receipt of nonalkylating chemotherapy (P = .01) were significant. Age <20 years at time of RT was borderline significant (P = .058). The model predicted a 2% risk of SOS with zero RT dose, 6.1% following 10 Gy, and 14.5% following 20 Gy to the whole liver (modeled as the linear-quadratic equivalent dose in 2-Gy fractions [α/β = 3 Gy]). Patients with Wilms tumor treated with right flank RT had a higher observed rate of SOS than patients receiving left flank RT, but data were insufficient to generate an NTCP model for partial liver irradiation. From the phantom-based dose reconstructions, mean liver dose was estimated to be 2.16 ± 1.15 Gy and 6.54 ± 2.50 Gy for left and right flank RT, respectively, using T10-T11 as the superior field border and a prescription dose of 10.8 Gy (based on dose reconstruction). Data were sparse regarding rates of late liver injury after RT, which suggests low rates of severe toxicity after treatment for common pediatric malignancies.

CONCLUSIONS

This pediatric normal tissue effects in the clinic (PENTEC) review provides an NTCP model to estimate the risk of hepatic SOS as a function of RT dose following whole liver RT and quantifies the range of mean liver doses from typical Wilms tumor flank irradiation fields. Patients treated with right flank RT had higher rates of SOS than patients treated with left flank RT, but data were insufficient to develop a model for partial liver irradiation. Risk of SOS was estimated to be approximately ≤6% in pediatric patients receiving whole liver doses of <10 Gy.

Volumetric modulated arc therapy based total marrow and lymphoid irradiation: Workflow and clinical experience

Background

The aim of this study is to report historical treatment planning experience at our institution for patients receiving total marrow and lymphatic irradiation (TMLI) using volumetric modulated arc therapy (VMAT) as part of the conditioning regimen prior to hematopoietic stem cell transplant.

Methods

We identified a total of fifteen patients with VMAT TMLI, ten with a prescription dose of 20 Gy (targeting the skeletal bones, lymph nodes, spleen, and spinal canal, with 12 Gy to the brain and liver) and five with a prescription dose of 12-16 Gy (targeting the skeletal bones, lymph nodes, spleen, and spinal canal). Representative dosimetric parameters including total treatment time, mean and median dose, D80, and D10 (dose covering 80% and 10% of the structure volume, respectively) for targets and normal organs were extracted and compared to historical patients treated with helical tomotherapy.

Results

The median treatment time for the first and subsequent fractions was 1.5 and 1.1 hours, respectively. All the target volumes had a mean dose greater than the prescribed dose except the ribs, which had an average mean dose of 19.5 Gy. The skeletal bones had an average mean dose of 21.1 Gy. The brain and liver have average mean doses of 14.8 and 14.1 Gy, respectively. The mean lung dose had an average of 7.6 ± 0.6 Gy for the 20-Gy cohort. Relative to the prescription dose of 20 Gy, the average mean dose for the normal organ volumes ranged from 16.5% to 72.0%, and the average median dose for the normal organs ranged from 16.5% to 71.0%. Dosimetry for patients treated to 12-16 Gy fell within expected ranges based on historical helical tomotherapy plans.

Conclusions

Dosimetric data in the VMAT TMLI plans at our institution are summarized for 20 Gy and 12-16 Gy cohorts. Dose distributions and treatment times are overall similar to plans generated with helical tomotherapy. TMLI may be delivered effectively using a VMAT technique, even at escalated doses.

ESTRO ACROP and SIOPE recommendations for myeloablative Total Body Irradiation in children

BACKGROUND AND PURPOSE

Myeloablative Total Body Irradiation (TBI) is an important modality in conditioning for allogeneic hematopoietic stem cell transplantation (HSCT), especially in children with high-risk acute lymphoblastic leukemia (ALL). TBI practices are heterogeneous and institution-specific. Since TBI is associated with multiple late adverse effects, recommendations may help to standardize practices and improve the outcome versus toxicity ratio for children.

MATERIAL AND METHODS

The European Society for Paediatric Oncology (SIOPE) Radiotherapy TBI Working Group together with ESTRO experts conducted a literature search and evaluation regarding myeloablative TBI techniques and toxicities in children. Findings were discussed in bimonthly virtual meetings and consensus recommendations were established.

RESULTS

Myeloablative TBI in HSCT conditioning is mostly performed for high-risk ALL patients or patients with recurring hematologic malignancies. TBI is discouraged in children <3-4 years old because of increased toxicity risk. Publications regarding TBI are mostly retrospective studies with level III-IV evidence. Preferential TBI dose in children is 12-14.4 Gy in 1.6-2 Gy fractions b.i.d. Dose reduction should be considered for the lungs to <8 Gy, for the kidneys to ≤10 Gy, and for the lenses to <12 Gy, for dose rates ≥6 cGy/min. Highly conformal techniques i.e. TomoTherapy and VMAT TBI or Total Marrow (and/or Lymphoid) Irradiation as implemented in several centers, improve dose homogeneity and organ sparing, and should be evaluated in studies.

CONCLUSIONS

These ESTRO ACROP SIOPE recommendations provide expert consensus for conventional and highly conformal myeloablative TBI in children, as well as a supporting literature overview of TBI techniques and toxicities.

Optimized Conformal Total Body Irradiation Among Recipients of TCRαβ/CD19-Depleted Grafts in Pediatric Patients With Hematologic Malignancies: Single-Center Experience

Total body irradiation (TBI) in combination with chemotherapy is widely used as a conditioning regimen in pediatric and adult hematopoietic stem cell transplantation (HSCT). The combination of TBI with chemotherapy has demonstrated superior survival outcomes in patients with acute lymphoblastic and myeloid leukemia when compared with conditioning regimens based only on chemotherapy. The clinical application of intensity-modulated radiation therapy (IMRT)-based methods (volumetric modulated arc therapy (VMAT) and TomoTherapy) seems to be promising and has been actively used worldwide. The optimized conformal total body irradiation (OC-TBI) method described in this study provides selected dose reduction for organs at risk with respect to the most significant toxicity (lungs, kidneys, lenses). This study included 220 pediatric patients who received OC-TBI with subsequent chemotherapy and allogenic HSCT with TCRαβ/CD19 depletion. A group of 151 patients received OC-TBI using TomoTherapy, and 40 patients received OC-TBI using the Elekta Synergy™ linac with an Agility-MLC (Elekta, Crawley, UK) using volumetric modulated arc therapy (VMAT). Twenty-nine patients received OC-TBI with supplemental simultaneous boost to bone marrow-(SIB to BM) up to 15 Gy: 28 patients (pts)-TomoTherapy; one patient-VMAT. The follow-up duration ranged from 0.3 to 6.4 years (median follow-up, 2.8 years). Overall survival (OS) for all the patients was 63% (95% CI: 56-70), and event-free survival (EFS) was 58% (95% CI: 51-65). The cumulative incidence of transplant-related mortality (TRM) was 10.7% (95% CI: 2.2-16) for all patients. The incidence of early TRM (<100 days) was 5.0% (95% CI: 1.5-8.9), and that of late TRM (>100 days) was 5.7 (95% CI: 1.7-10.2). The main causes of death for all the patients were relapse and infection. The concept of OC-TBI using IMRT VMAT and helical treatment delivery on a TomoTherapy treatment unit provides maximum control of the dose distribution in extended targets with simultaneous dose reduction for organs at risk. This method demonstrated a low incidence of severe side effects after radiation therapy and predictable treatment effectiveness. Our initial experience demonstrates that OC-TBI appears to be a promising technique for the treatment of pediatric patients.

Total Body Irradiation in Haematopoietic Stem Cell Transplantation for Paediatric Acute Lymphoblastic Leukaemia: Review of the Literature and Future Directions

Total body irradiation (TBI) has been a pivotal component of the conditioning regimen for allogeneic myeloablative haematopoietic stem cell transplantation (HSCT) in very-high-risk acute lymphoblastic leukaemia (ALL) for decades, especially in children and young adults. The myeloablative conditioning regimen has two aims: (1) to eradicate leukaemic cells, and (2) to prevent rejection of the graft through suppression of the recipient's immune system. Radiotherapy has the advantage of achieving an adequate dose effect in sanctuary sites and in areas with poor blood supply. However, radiotherapy is subject to radiobiological trade-offs between ALL cell destruction, immune and haematopoietic stem cell survival, and various adverse effects in normal tissue. To diminish toxicity, a shift from single-fraction to fractionated TBI has taken place. However, HSCT and TBI are still associated with multiple late sequelae, leaving room for improvement. This review discusses the past developments of TBI and considerations for dose, fractionation and dose-rate, as well as issues regarding TBI setup performance, limitations and possibilities for improvement. TBI is typically delivered using conventional irradiation techniques and centres have locally developed heterogeneous treatment methods and ways to achieve reduced doses in several organs. There are, however, limitations in options to shield organs at risk without compromising the anti-leukaemic and immunosuppressive effects of conventional TBI. Technological improvements in radiotherapy planning and delivery with highly conformal TBI or total marrow irradiation (TMI), and total marrow and lymphoid irradiation (TMLI) have opened the way to investigate the potential reduction of radiotherapy-related toxicities without jeopardising efficacy. The demonstration of the superiority of TBI compared with chemotherapy-only conditioning regimens for event-free and overall survival in the randomised For Omitting Radiation Under Majority age (FORUM) trial in children with high-risk ALL makes exploration of the optimal use of TBI delivery mandatory. Standardisation and comprehensive reporting of conventional TBI techniques as well as cooperation between radiotherapy centres may help to increase the ratio between treatment outcomes and toxicity, and future studies must determine potential added benefit of innovative conformal techniques to ultimately improve quality of life for paediatric ALL patients receiving TBI-conditioned HSCT.

Current Prophylaxis and Treatment Approaches for Acute Graft-Versus-Host Disease in Haematopoietic Stem Cell Transplantation for Children With Acute Lymphoblastic Leukaemia

Acute graft-versus-host disease (aGvHD) continues to be a leading cause of morbidity and mortality following allogeneic haematopoietic stem cell transplantation (HSCT). However, higher event-free survival (EFS) was observed in patients with acute lymphoblastic leukaemia (ALL) and grade II aGvHD vs. patients with no or grade I GvHD in the randomised, controlled, open-label, international, multicentre Phase III For Omitting Radiation Under Majority age (FORUM) trial. This finding suggests that moderate-severity aGvHD is associated with a graft-versus-leukaemia effect which protects against leukaemia recurrence. In order to optimise the benefits of HSCT for leukaemia patients, reduction of non-relapse mortality-which is predominantly caused by severe GvHD-is of utmost importance. Herein, we review contemporary prophylaxis and treatment options for aGvHD in children with ALL and the key challenges of aGvHD management, focusing on maintaining the graft-versus-leukaemia effect without increasing the severity of GvHD.

A Review of Acute and Long-Term Neurological Complications Following Haematopoietic Stem Cell Transplant for Paediatric Acute Lymphoblastic Leukaemia

Despite advances in haematopoietic stem cell transplant (HSCT) techniques, the risk of serious side effects and complications still exists. Neurological complications, both acute and long term, are common following HSCT and contribute to significant morbidity and mortality. The aetiology of neurotoxicity includes infections and a wide variety of non-infectious causes such as drug toxicities, metabolic abnormalities, irradiation, vascular and immunologic events and the leukaemia itself. The majority of the literature on this subject is focussed on adults. The impact of the combination of neurotoxic drugs given before and during HSCT, radiotherapy and neurological complications on the developing and vulnerable paediatric and adolescent brain remains unclear. Moreover, the age-related sensitivity of the nervous system to toxic insults is still being investigated. In this article, we review current evidence regarding neurotoxicity following HSCT for acute lymphoblastic leukaemia in childhood. We focus on acute and long-term impacts. Understanding the aetiology and long-term sequelae of neurological complications in children is particularly important in the current era of immunotherapy for acute lymphoblastic leukaemia (such as chimeric antigen receptor T cells and bi-specific T-cell engager antibodies), which have well-known and common neurological side effects and may represent a future treatment modality for at least a fraction of HSCT-recipients.

Change of White Matter Integrity in Children With Hematopoietic Stem Cell Transplantation

BACKGROUND

Advances in hematopoietic stem cell transplantation have improved the survival rate of malignant diseases and congenital immunodeficiencies. It has become important to assess long-term complications in survivors. To assess neurological abnormalities in children treated by transplantation, diffusion tensor imaging was performed.

METHODS

Forty children who underwent head diffusion tensor imaging before and after their first transplantation were enrolled. Patients with brain lesions on conventional MRI were excluded. Fractional anisotropy and mean diffusivity were compared between patients and 28 control subjects using tract-based spatial statistics. The Strengths and Difficulties Questionnaire was administered as a behavioral evaluation after transplantation, and diffusion tensor images of patients with and without behavioral abnormalities were compared.

RESULTS

The age of patients and controls was 0 to 19 years and 0 to 16 years, respectively. The date of diffusion tensor imaging was 10 to 57 days before and 40 to 153 days after transplantation. Tract-based spatial statistics showed fractional anisotropy reduction in widespread white matter in patients before and after transplantation. Mean diffusivity was high before transplantation and normalized after transplantation. Analysis comparing before and after hematopoietic stem cell transplantation shows no difference in fractional anisotropy and a higher mean diffusivity before hematopoietic stem cell transplantation. In patients with behavioral abnormalities, low fractional anisotropy and high mean diffusivity remained after transplantation.

CONCLUSIONS

Longitudinal diffusion tensor imaging showed white matter abnormalities in children without conventional MRI abnormalities, which were related to behavioral problems after transplantation. Diffusion tensor imaging is useful for behavioral assessment in children undergoing transplantation.

Comparing the outcomes between TMLI and non-TMLI conditioning regimens for adult high-risk acute lymphoblastic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation: a single-center experience

This study aimed to retrospectively evaluate the outcomes of adult patients with high-risk acute lymphoblastic leukemia (ALL) who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) with either total marrow and lymphoid irradiation (TMLI)-containing or non-TMLI conditioning regimen. Seventy adult patients with high-risk ALL who received allo-HSCT were enrolled in this study and divided into two groups based on the conditioning regimen type (TMLI group: n = 29 and non-TMLI group: n = 41). We noted significant statistical differences in the 1-year estimated cumulative incidence of relapse (25% vs. 46.5%, p = 0.018), the 1-year estimated overall survival (73.1% vs. 52.6%, p = 0.033) and disease-free survival (65.2% vs. 48.2%, p = 0.026) but found no considerable difference in transplant-related mortality (12% vs. 13.4%, p = 0.619) between patients in the TMLI and non-TMLI groups. The TMLI-containing regimen is safe and alternative for patients with high-risk ALL undergoing allo-HSCT.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately, the improved prognosis has been accompanied by the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors, the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies, it is important to know the risk of, and associated risk factors for, hepatic late adverse effects. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate all the existing evidence on the association between antineoplastic treatment (that is, chemotherapy, radiotherapy involving the liver, surgery involving the liver and BMT) for childhood cancer and hepatic late adverse effects.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2018, Issue 1), MEDLINE (1966 to January 2018) and Embase (1980 to January 2018). In addition, we searched reference lists of relevant articles and scanned the conference proceedings of the International Society of Paediatric Oncology (SIOP) (from 2005 to 2017) and American Society of Pediatric Hematology/Oncology (ASPHO) (from 2013 to 2018) electronically.

SELECTION CRITERIA

All studies, except case reports, case series, and studies including fewer than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection and 'risk of bias' assessment. The 'risk of bias' assessment was based on earlier checklists for observational studies. For the original version of the review, two review authors independently performed data extraction. For the update of the review, the data extraction was performed by one reviewer and checked by another reviewer.

MAIN RESULTS

Thirteen new studies were identified for the update of this review. In total, we included 33 cohort studies including 7876 participants investigating hepatic late adverse effects after antineoplastic treatment (especially chemotherapy and radiotherapy) for different types of childhood cancer, both haematological and solid malignancies. All studies had methodological limitations. The prevalence of hepatic late adverse effects, all defined in a biochemical way, varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well-defined as alanine aminotransferase (ALT) above the upper limit of normal, indicating cellular liver injury, resulted in eight studies. In this subgroup, the prevalence of hepatic late adverse effects ranged from 5.8% to 52.8%, with median follow-up durations varying from three to 23 years since cancer diagnosis in studies that reported the median follow-up duration. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal, resulted in five studies, with a prevalence ranging from 0.9% to 44.8%. One study investigated biliary tract injury, defined as gamma-glutamyltransferase (γGT) above the upper limit of normal and above twice the upper limit of normal and reported a prevalence of 5.3% and 0.9%, respectively. Three studies investigated disturbance in biliary function, defined as bilirubin above the upper limit of normal and reported prevalences ranging from 0% to 8.7%. Two studies showed that treatment with radiotherapy involving the liver (especially after a high percentage of the liver irradiated), higher BMI, and longer follow-up time or older age at evaluation increased the risk of cellular liver injury in multivariable analyses. In addition, there was some suggestion that busulfan, thioguanine, hepatic surgery, chronic viral hepatitis C, metabolic syndrome, use of statins, non-Hispanic white ethnicity, and higher alcohol intake (> 14 units per week) increase the risk of cellular liver injury in multivariable analyses. Chronic viral hepatitis was shown to increase the risk of cellular liver injury in six univariable analyses as well. Moreover, one study showed that treatment with radiotherapy involving the liver, higher BMI, higher alcohol intake (> 14 units per week), longer follow-up time, and older age at cancer diagnosis increased the risk of biliary tract injury in a multivariable analysis.

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects among studies with an adequate outcome definition varied considerably from 1% to 53%. Evidence suggests that radiotherapy involving the liver, higher BMI, chronic viral hepatitis and longer follow-up time or older age at follow-up increase the risk of hepatic late adverse effects. In addition, there may be a suggestion that busulfan, thioguanine, hepatic surgery, higher alcohol intake (>14 units per week), metabolic syndrome, use of statins, non-Hispanic white ethnicity, and older age at cancer diagnosis increase the risk of hepatic late adverse effects. High-quality studies are needed to evaluate the effects of different therapy doses, time trends, and associated risk factors after antineoplastic treatment for childhood cancer.

Skeletal Morbidity in Children and Adolescents during and following Cancer Therapy

Skeletal abnormalities are common in children and adolescents diagnosed and treated for a malignancy. The spectrum ranges from mild pain to debilitating osteonecrosis and fractures. In this review, we summarize the impact of cancer therapy on the developing skeleton, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life in childhood cancer survivors.

Appropriate treatment planning method for field joint dose in total body irradiation using helical tomotherapy

Total body irradiation (TBI) using helical tomotherapy (HT) has advantages over the standard linear accelerator-based approach to the conditioning regimen for hematopoietic cell transplantation. However, the radiation field has to be divided into two independent irradiation plans to deliver a homogeneous dose to the whole body. A clinical target volume near the skin increases the skin surface dose; therefore, high- or low-dose regions arise depending on the set-up position accuracy because the two radiation fields are somewhat overlapped or separated. We aimed to determine an adequate treatment planning method robust to the set-up accuracy for the field joint dose distribution using HT-TBI. We calculated treatment plans reducing target volumes at the interface between the upper and lower body irradiations and evaluated these joint dose distributions via simulation and experimental studies. Target volumes used for the optimization calculation were reduced by 0, 0.5, 1.0, 2.0, 2.5, and 3.0 cm from the boundary surface on the upper and lower sides. Combined dose distributions with set-up error simulated by modifying coordinate positions were investigated to find the optimal planning method. In the ideal set-up position, the target volume without a gap area caused field junctional doses of up to approximately 200%; therefore, target volumes reduced by 2.0-3.0 cm could suppress the maximum dose to within 150%. However, with set-up error, high-dose areas exceeding 150% and low-dose areas below 100% were found with 2.0 and 3.0 cm target volume reduction. Using the dynamic jaw (DJ) system, dose deviations caused by set-up error reached approximately 20%, which is not suitable for HT-TBI. Moreover, these dose distributions can be easily adjusted when combined with the intensity modulation technique for field boundary regions. The results of a simulation and experimental study using a film dosimetry were almost identical, which indicated that reducing the target volume at the field boundary surface by 2.5 cm produces the most appropriate target definition.

Musculoskeletal complications following total body irradiation in hematopoietic stem cell transplant patients

Total body irradiation (TBI) is commonly used in conditioning regimens for allogeneic hematopoietic stem cell transplantation (HSCT) to treat benign and malignant disease. Though life-saving, these therapies place patients at risk for important side effects, including musculoskeletal complications such as short stature, osteonecrosis, slipped capital femoral epiphysis, and the development of benign and malignant bone tumors. With an increasing number of HSCT survivors, there is a growing need for awareness of the musculoskeletal complications of HSCT and TBI.

Total body irradiation in allogeneic bone marrow transplantation conditioning regimens: A review

Hematologic malignancies may require, at one point during their treatment, allogeneic bone marrow transplantation. Total body irradiation combined with chemotherapy or radiomimetic used in allogeneic bone marrow transplantation is known to be very toxic. Total body irradiation (TBI) induces immunosuppression to prevent the rejection of donor marrow. TBI is also used to eradicate malignant cells and is in sanctuary organs that are not reached by chemotherapy drugs. TBI has evolved since its introduction in the late fifties, but acute and late toxicities remain. Helical tomotherapy, which is widely used for some solid tumors, is a path for the improvement of outcomes and toxicities in TBI because of its sparing capacities. In this article, we first review the practical aspects of TBI with patient positioning, radiobiological considerations and total dose and fractionation prescriptions. Second, we review the use of intensity modulated radiation therapy in bone marrow transplantation with a focus on helical tomotherapy TBI, helical tomotherapy total marrow irradiation (TMI) and total marrow and lymphoid irradiation (TMLI) and their dosimetric and clinical outcomes. Finally, we review the perspective of dose escalation and the extension to older patients and patients with comorbidity who do not benefit from a standard bone marrow transplantation conditioning regimen.

Neurocognitive dysfunction in hematopoietic cell transplant recipients: expert review from the late effects and Quality of Life Working Committee of the CIBMTR and complications and Quality of Life Working Party of the EBMT

Hematopoietic cell transplantation (HCT) is a potentially curative treatment for children and adults with malignant and non-malignant diseases. Despite increasing survival rates, long-term morbidity following HCT is substantial. Neurocognitive dysfunction is a serious cause of morbidity, yet little is known about neurocognitive dysfunction following HCT. To address this gap, collaborative efforts of the Center for International Blood and Marrow Transplant Research and the European Society for Blood and Marrow Transplantation undertook an expert review of neurocognitive dysfunction following HCT. In this review, we define what constitutes neurocognitive dysfunction, characterize its risk factors and sequelae, describe tools and methods to assess neurocognitive function in HCT recipients, and discuss possible interventions for HCT patients with this condition. This review aims to help clinicians understand the scope of this health-related problem, highlight its impact on well-being of survivors, and to help determine factors that may improve identification of patients at risk for declines in cognitive functioning after HCT. In particular, we review strategies for preventing and treating neurocognitive dysfunction in HCT patients. Lastly, we highlight the need for well-designed studies to develop and test interventions aimed at preventing and improving neurocognitive dysfunction and its sequelae following HCT.

Haploidentical hematopoietic SCT using helical tomotherapy for total-body irradiation and targeted dose boost in patients with high-risk/refractory acute lymphoblastic leukemia

A novel conditioning regimen using helical tomotherapy (HT) was developed to deliver 10 Gy for total body irradiation (TBI) and simultaneously augment dose to 12 Gy for targeted dose boost to total marrow, central nervous system leukemia, and extramedullary disease sites in patients with high-risk or relapsed/refractory acute lymphoblastic leukemia (ALL) receiving haploidentical allogeneic hematopoietic stem cell transplantation (allo-HSCT). Fourteen patients were included, eight of these patients were in first complete remission (CR1), one was in CR2, one had a partial response and four patients had refractory disease at transplantation. The median delivered average dose was 11.395 Gy (range 10.06-12.17). The median planning target volume D95 was 8.2 Gy (range 7.52-9.01). The median delivered dose to skeleton bone with active bone marrow sites was 12.685 Gy (range 11.12-13.52). The results of this trial suggest that using HT TBI confers satisfactory immunosuppression and excellent eradication of malignant cells in patients with high-risk ALL undergoing allo-HSCT, especially in those with refractory ALL. After a median follow-up of 14.6 months (range 4-28), four patients experienced non-relapse mortality, ten patients are alive in durable CR including remission of extramedullary leukemic infiltration. One-year overall survival and disease-free survival rates post-transplantation were both 70.7%.

Neurocognitive Dysfunction in Hematopoietic Cell Transplant Recipients: Expert Review from the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and Complications and Quality of Life Working Party of the European Society for Blood and Marrow Transplantation

Hematopoietic cell transplantation (HCT) is a potentially curative treatment for children and adults with malignant and nonmalignant diseases. Despite increasing survival rates, long-term morbidity after HCT is substantial. Neurocognitive dysfunction is a serious cause of morbidity, yet little is known about neurocognitive dysfunction after HCT. To address this gap, collaborative efforts of the Center for International Blood and Marrow Transplant Research and the European Society for Blood and Marrow Transplantation undertook an expert review of neurocognitive dysfunction after HCT. In this review we define what constitutes neurocognitive dysfunction, characterize its risk factors and sequelae, describe tools and methods to assess neurocognitive function in HCT recipients, and discuss possible interventions for HCT patients with this condition. This review aims to help clinicians understand the scope of this health-related problem, highlight its impact on well-being of survivors, and help determine factors that may improve identification of patients at risk for declines in cognitive functioning after HCT. In particular, we review strategies for preventing and treating neurocognitive dysfunction in HCT patients. Finally, we highlight the need for well-designed studies to develop and test interventions aimed at preventing and improving neurocognitive dysfunction and its sequelae after HCT.

Adequate target volume in total-body irradiation by intensity-modulated radiation therapy using helical tomotherapy: a simulation study

Recently, intensity-modulated radiation therapy (IMRT) has been used for total-body irradiation (TBI). Since the planning target volume (PTV) for TBI includes the surrounding air, a dose prescription to the PTV provides high fluence to the body surface. Thus with just a small set-up error, the body might be exposed to a high-fluence beam. This study aims to assess which target volume should be prescribed the dose, such as a clinical target volume (CTV) with a margin, or a CTV that excludes the surface area of the skin. Three treatment plans were created for each patient: the 5-mm clipped plan (Plan A), the 0-mm margin plan (Plan B) and the 5-mm margin plan (Plan C). The CTV was the whole body. PTVs were the CTV with the exception of 5 mm from the skin surface in Plan A, equal to the CTV in Plan B, and the CTV with a 5 mm margin in Plan C. The prescribed dose was 12 Gy in six fractions. To assess the influence of the set-up error, dose distributions were simulated on computed tomography (CT) images shifted 2 pixels (= 4.296 mm), 5 pixels (= 10.74 mm) and 10 pixels (= 21.48 mm) in the lateral direction from the original CT. With a set-up error of 10.74 mm, V110% was 8.8%, 11.1% and 23.3% in Plans A, B and C, respectively. The prescription to the PTV containing the surrounding air can be paradoxically vulnerable to a high-dose as a consequence of a small set-up error.

Comparing proton treatment plans of pediatric brain tumors in two pencil beam scanning nozzles with different spot sizes

Target coverage and organ‐at‐risk sparing were compared for 22 pediatric patients with primary brain tumors treated using two distinct nozzles in pencil beam scanning (PBS) proton therapy. Consecutive patients treated at our institution using a PBS‐dedicated nozzle (DN) were replanned using a universal nozzle (UN) beam model and the original DN plan objectives. Various cranial sites were treated among the patients to prescription doses ranging from 45 to 54 Gy. Organs at risk (OARs) evaluated were patient‐dependent; 15 unique OARs were analyzed, all of which were assessed in at least 10 patients. Clinical target volume (CTV) coverage and organ sparing were compared for the two nozzles using dose‐volume histogram data. Statistical analysis using a confidence‐interval approach demonstrates that CTV coverage is equivalent for UN and DN plans within ±5% equivalence bounds. In contrast, average mean and maximum doses are significantly higher for nearly all 15 OARs in the UN plans. The average median increase over all OARs and patients is approximately 1.7 Gy, with an increase in the 25%–75% of 1.0–2.3 Gy; the median increase to the pituitary gland, temporal lobes, eyes and cochleas are 1.8, 1.7, 0.7, and 2.7 Gy, respectively. The CTV dose distributions fall off slower for UN than for the DN plans; hence, normal tissue structures in close proximity to CTVs receive higher doses in UN plans than in DN plans. The higher OAR doses in the UN plans are likely due to the larger spot profile in plans created with UN beams. In light of the high rates of toxicities in pediatric patients receiving cranial irradiation and in light of selected brain tumor types having high cure rates, this study suggests the smaller DN beam profile is preferable for the advantage of reducing dose to OARs.

PACS number: 87.55.D‐

Hepatotoxicity after liver irradiation in children and adolescents : results from the RiSK

AIM

The aim of this study was to evaluate acute and late radiotherapy-associated hepatotoxicity in consideration of dose-volume effects and liver function in childhood and adolescence.

PATIENTS AND METHODS

Since 2001, irradiated children and adolescents in Germany have been prospectively documented in the "Register of Treatment-Associated Late Effects After Radiotherapy of Malignant Diseases in Childhood and Adolescence (RiSK)" using standardized forms. Toxicity was graded according to the Radiation Therapy Oncology Group (RTOG) criteria.

RESULTS

Until April 2012, 1,392 children and adolescents from 62 radiotherapy centers were recruited. In all, 216 patients underwent irradiation of the liver (median age 9 years, range 1-18 years, 70 patients with total-body irradiation, TBI). For 75 % of patients without TBI, information on acute toxicity of the liver was available: 24 patients had acute toxicity of grade 1-4 (grade 1, 2, and 4, in 20, 3, and 1 patient, respectively), including five patients receiving simultaneous hepatotoxic chemotherapy. Information on late toxicity was documented in 465 forms from 216 patients, with a median follow-up of 2 years. A maximum grade of toxicity of ≥ 0 occurred in 18 patients over time (with grade 1, 2, and 3 toxicity occurring in 15, 2, and 1 patient, respectively), including three patients (17 %) with TBI. One of them received simultaneous hepatotoxic chemotherapy. In multivariable analysis, volume-dose correlations showed no statistically noticeable effect on acute or chronic toxicity.

CONCLUSION

Only low hepatotoxicity developed in children after irradiation of various abdominal and thoracic tumors. Due to the low radiation doses to the liver (median liver dose = 5 Gy) and the low toxicities that were consecutively observed, dose-volume curves for liver toxicity could not be established. These findings reflect the cautious attitude of radiation oncologists in terms of attributable liver doses in the treatment of the investigated tumor entities. It offers the option of increasing these conservative doses if tumor control is necessary.

Effects of total body irradiation-based conditioning on allogeneic stem cell transplantation for pediatric acute leukemia: a single-institution study

Purpose

To evaluate the effects of total body irradiation (TBI), as a conditioning regimen prior to allogeneic stem cell transplantation (allo-SCT), in pediatric acute leukemia patients.

Materials and Methods

From January 2001 to December 2011, 28 patients, aged less than 18 years, were treated with TBI-based conditioning for allo-SCT in our institution. Of the 28 patients, 21 patients were diagnosed with acute lymphoblastic leukemia (ALL, 75%) and 7 were diagnosed with acute myeloid leukemia (AML, 25%). TBI was completed 4 days or 1 day before stem cell infusion. Patients underwent radiation therapy with bilateral parallel opposing fields and 6-MV X-rays. The Kaplan-Meier method was used to calculate survival outcomes.

Results

The 2-year event-free survival and overall survival rates were 66% and 56%, respectively (71.4% and 60.0% in AML patients vs. 64.3% and 52.4% in ALL patients, respectively). Treatment related mortality rate were 25%. Acute and chronic graft-versus-host disease was a major complication; other complications included endocrine dysfunction and pulmonary complications. Common complications from TBI were nausea (89%) and cataracts (7.1%).

Conclusion

The efficacy and toxicity data in this study of TBI-based conditioning to pediatric acute leukemia patients were comparable with previous studies. However, clinicians need to focus on the acute and chronic complications related to allo-SCT.

Delayed renal dysfunction after total body irradiation in pediatric malignancies

The purpose of this study was to retrospectively evaluate the incidence of delayed renal dysfunction after total body irradiation (TBI) in long-term survivors of TBI/hematopoietic stem cell transplantation (HSCT). Between 1989 and 2006, 24 pediatric patients underwent TBI as part of the conditioning regimen for HSCT at Chiba University Hospital. Nine patients who survived for more than 5 years were enrolled in this study. No patient had any evidence of renal dysfunction prior to the transplant according to their baseline creatinine levels. The median age at the time of diagnosis was 6 years old (range: 1-17 years old). The follow-up period ranged from 79-170 months (median: 140 months). Renal dysfunction was assessed using the estimated glomerular filtration rate (eGFR). The TBI dose ranged from 8-12 Gy delivered in 3-6 fractions over 2-3 d. The patients were treated with linear accelerators in the supine position, and the radiation was delivered to isocentric right-left and left-right fields via the extended distance technique. The kidneys and the liver were not shielded except in one patient with a left adrenal neuroblastoma. No patient required hemodialysis. The eGFR of four patients (44.4%) progressively decreased. The remaining patients did not demonstrate any eGFR deterioration. Only one patient developed hypertension. By evaluating the changes in eGFR, renal dysfunction among long-term survivors of TBI/HSCT could be detected. Our results suggested that the TBI schedule of 12 Gy in 6 fractions over three consecutive days affects renal function.

Second cancers and late mortality in Australian children treated by allogeneic HSCT for haematological malignancy

We examined risk of second cancer and late mortality in a population-based Australian cohort of 717 pediatric allogeneic stem cell transplant (HSCT) recipients treated for a malignant disease during 1982-2007. Record linkage with population-based death and cancer registries identified 17 second cancers at a median of 7.9 years post HSCT; thyroid cancer being the most common malignancy (n=8). The cumulative incidence of second cancer was 8.7% at follow-up, and second cancers occurred 20 times more often than in the general population (standardised incidence ratio 20.3, 95% confidence interval (CI)=12.6-32.7). Transplantation using radiation-based conditioning regimens was associated with increased second cancer risk. A total of 367 patients survived for at least 2 years post HSCT and of these 44 (12%) died at a median of 3.1 years after HSCT. Relapse was the most common cause of late mortality (n=32). The cumulative incidence of late mortality was 14.7%. The observed rate of late mortality was 36 times greater than in the matched general population (standardised mortality ratio 35.9, 95% CI=26.7-48.3). Recipients who relapsed or who had radiation-based conditioning regimens were at higher risk of late mortality. Second cancers and late mortality continue to be a risk for pediatric patients undergoing HSCT, and these results highlight the need for effective screening and survivorship programs.

Thrombotic microangiopathy in metastatic melanoma patients treated with adoptive cell therapy and total body irradiation

BACKGROUND

Thrombotic microangiopathy (TMA) is a complication that developed in some patients receiving 12 Gy total body irradiation (TBI) in addition to lymphodepleting preparative chemotherapy prior to infusion of autologous tumor-infiltrating lymphocytes (TIL) with high-dose aldesleukin (IL-2). This article describes the incidence, presentation, and course of radiation-associated TMA.

METHODS

The data for patients with metastatic melanoma who received ACT with TIL plus aldesleukin following myeloablative chemotherapy and 12-Gy TBI was examined, in order to look at patient characteristics and the natural history of TMA.

RESULTS

The median time to presentation was approximately 8 months after completing TBI. The estimated cumulative incidence of TMA was 31.2% (median follow-up of 24 months). Noninvasive criteria for diagnosis included newly elevated creatinine levels, new-onset hypertension, new-onset anemia, microscopic hematuria, thrombocytopenia, low haptoglobin, and elevated lactate dehydrogenase values. Once diagnosed, patients were managed with control of their hypertension with multiple agents and supportive red blood cell transfusions. TMA typically stabilized or improved and no patient progressed to dialysis. TMA was associated with a higher probability of an antitumor response.

CONCLUSIONS

TMA occurs in approximately a third of patients treated with a lymphodepleting preparative chemotherapy regimen with TBI prior to autologous T cell therapy. The disease has a variable natural history, however, no patient developed end-stage renal failure. Successful management with supportive care and aggressive hypertension control is vital to the safe application of a systemic therapy that has shown curative potential for patients with disseminated melanoma.

Osteochondroma with metaphyseal abnormalities after total body irradiation followed by stem cell transplantation

The occurrence of osteochondroma after total body irradiation (TBI) followed by stem cell transplantation (SCT) in our institutions was described, and its clinical significance discussed. Of 305 cases treated with SCT using TBI conditioning from 1980 to 2001, 4 cases of osteochondroma were identified on clinical examination. Mean age at the time of TBI was 4.4 years (range, 1.6 to 8.0). One patient developed multiple osteochondromas. All 4 cases showed metaphyseal abnormalities, including sclerotic metaphyseal lesion, fraying, and longitudinal striation, in the area where osteochondromas occurred. Only 1 patient required resection of the tumor due to pain. Two cases had other skeletal abnormalities including slipped capital femoral epiphysis and valgus-knee deformity, which required surgical intervention to prevent or correct these deformities. Osteochondroma is one of the complications developing after TBI, possibly concurrently with the metaphyseal abnormalities as seen on radiographs. However, clinical problems arising from osteochondroma are minimal, and surgical intervention is necessary in limited cases.

NCI, NHLBI/PBMTC First International Conference on Late Effects after Pediatric Hematopoietic Cell Transplantation: health-related quality of life, functional, and neurocognitive outcomes

The purpose of this manuscript is to summarize issues relevant to health-related quality of life (HRQL), physical function, and neurocognitive function for survivors of pediatric hematopoietic stem cell transplantation (HCT). The physiologic and psychological demands of HCT and its sequelae have the potential to substantially alter HRQL. When compared with research on adult HCT recipients, research in pediatric HRQL following HCT has lagged considerably. Initially, this lag was because of limited validated questionnaires, small numbers of affected patients, and a general lack of salience for the topic relative to traditional endpoints, such as transplant-related toxicity and potential mortality. The percentage of childhood HCT survivors with physical disability ranges from 7% to 17% in studies where the outcome was based on clinician or self-report measures, to over 40% in studies where the outcome was based on a directly measured physical performance task. Direct and comprehensive measures of physical performance may help further clarify the proportion of individuals who have subclinical problems amenable to intervention before apparent functional loss becomes a problem. There is a need to include longer term survivors in such an assessment. In terms of neurocognitive function, the majority of reports demonstrate relatively good function in survivors. However, it is clear that little or no data on outcomes beyond 5 years posttransplant have been obtained, and clinicians working with this population remain concerned regarding the cognitive functions of these survivors. Research focused on these domains should attempt to better understand the prevalence of the problem using child self-report and direct measurements of function, standardize measurement methods, and tools across trials, obtain longer term evaluations and begin to consider interventional trials.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately the improved prognosis has resulted in the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies it is important to know the risk of, and associated risk factors for, hepatic late adverse effects.

OBJECTIVES

To evaluate the existing evidence on the association between antineoplastic treatment for childhood cancer and hepatic late adverse effects.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 2), MEDLINE (1966 to June 2009) and EMBASE (1980 to June 2009). In addition, we searched reference lists of relevant articles and conference proceedings.

SELECTION CRITERIA

All studies except case reports, case series and studies including less than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias assessment and data extraction.

MAIN RESULTS

We identified 20 cohort studies investigating hepatic late adverse effects after antineoplastic treatment for childhood cancer. All studies had methodological limitations. The prevalence of hepatic late adverse effects varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well defined as alanine aminotransferase (ALT) above the upper limit of normal resulted in five studies. In this subgroup the prevalence of hepatic late adverse effects ranged from 8.0% to 52.8%, with follow-up durations varying from one to 27 years after the end of treatment. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal resulted in three studies, with a prevalence ranging from 7.9% to 44.8%. Chronic viral hepatitis was identified as a risk factor for hepatic late adverse effects in univariate analyses. It is unclear which specific antineoplastic treatments increase the risk of hepatic late adverse effects

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects ranged from 7.9% to 52.8% when selecting studies with an adequate outcome definition. It has not been established which childhood cancer treatments result in hepatic late adverse effects. There is a suggestion that chronic viral hepatitis increases the risk of hepatic late adverse effects. More well-designed studies are needed to reliably evaluate the prevalence of, and risk factors for, hepatic late adverse effects after antineoplastic treatment for childhood cancer.

Cognitive and behavioral abnormalities in children after hematopoietic stem cell transplantation for severe congenital immunodeficiencies

Hematopoietic stem cell transplantation (HSCT) is a highly successful treatment for severe congenital immunodeficiencies. However, some studies have suggested that children may experience cognitive difficulties after HSCT. This large-scale study assessed cognitive and behavioral function for the cohort of children treated by HSCT at one center between 1979 and 2003 to determine the frequency and severity of problems and to identify risk factors. A total of 105 patients were assessed on standardized measures of cognitive and emotional and behavioral function together with a control group of unaffected siblings. The average IQ for the cohort was 85 (95% confidence interval, 81-90), significantly lower than both the population average of 100 (P < .001) and unaffected siblings. Multivariate analysis indicated that the underlying genetic defect, diagnosis of adenosine deaminase-deficient severe combined immunodeficiency, and consanguinity were associated with worse outcome but that age at transplantation and chemotherapy conditioning were not. Children treated by HSCT for severe immunodeficiency have an increased risk of long-term cognitive difficulties and associated emotional and behavioral difficulties. The specific genetic diagnosis, consanguinity, and severe clinical course are associated with poor outcome. Long-term follow-up of these patients should include screening to identify and manage these problems more effectively.

Progressive declines in neurocognitive function among survivors of hematopoietic stem cell transplantation for pediatric hematologic malignancies

Neurocognitive function of pediatric patients is of great concern after hematopoietic stem cell transplantation (HSCT). We evaluated the neurocognitive function of pediatric patients pre-HSCT, 1, 3, and 5 years post-HSCT. All patients had a hematologic malignancy and received therapy to their central nervous system. Healthy siblings were tested as a comparison group. Pediatric patients with a hematologic malignancy did not have a significant decrease in their cognitive function before HSCT compared with their siblings except in areas of academic achievement. Our study population had significant declines in visual motor skills and memory test scores within the first year post-HSCT. By 3 years post-HSCT, there was an improvement in the visual motor development scores and memory scores, but there were new deficits in verbal skills. By 5 years post-HSCT, there were progressive declines in verbal skills (P=0.005), performance skills (0.04), and new deficits seen in long-term verbal memory scores (0.04). On the basis of the raw scores, most of these tests showed that patients had an inability to acquire new skills at a rate comparable to their age-matched healthy peers. However, long-term memory scores showed definite declines. The greatest decline in neurocognitive function occurred in those patients who received cranial irradiation either as part of their initial therapy or as part of their HSCT conditioning. Pediatric patients who received HSCT for hematologic malignancies have neurocognitive deficiencies that are both acute and chronic. Although some patients have acute deficits that appear and improve over time, other patients have progressive declines in neurocognitive function that are chronic.

Cognitive and Academic Consequences of Stem-Cell Transplantation in Children

Purpose

To describe cognitive and academic outcomes in survivors after pediatric stem-cell transplantation (SCT) through 5-years post-SCT.

Patients and Methods

A battery of neurocognitive measures were administered before admission and at 1, 3, and 5 years post-SCT for 268 patients who underwent SCT; the study sample is comprised of 158 patients who survived and were evaluated at 1-year post-SCT. Random coefficient models were generated to depict change over time, and to test differences in slope and intercept for medical and demographic predictor variables.

Results

In the cohort as a whole, no significant changes were seen in global intelligence quotient and academic achievement. Despite the overall stability, some significant differences in slopes were found based on diagnosis, type of transplantation, use of total-body irradiation (TBI), and presence of graft-versus-host disease (GVHD). However, these differences were small, and of limited clinical significance. In comparison, differences as a function of socioeconomic status (SES) were much larger. SES was a significant determinant of all cognitive and academic outcomes, and the effect size generally dwarfed that of other significant predictor variables. Age, which had previously been identified as an important determinant of outcome, was not significantly predictive of outcome in this cohort.

Conclusion

The procedure of SCT entails minimal risk of late cognitive and academic sequelae. Subgroups of patients are at relatively higher risk: patients undergoing unrelated donor transplantation, receiving TBI, and those who experience GVHD. However, these differences are small relative to differences in premorbid functioning, particularly those associated with SES.

Impact of drug therapy, radiation dose, and dose rate on renal toxicity following bone marrow transplantation

PURPOSE

To demonstrate a radiation dose response and to determine the dosimetric and chemotherapeutic factors that influence the incidence of late renal toxicity following total body irradiation (TBI).

METHODS AND MATERIALS

A comprehensive retrospective review was performed of articles reporting late renal toxicity, along with renal dose, fractionation, dose rate, chemotherapy regimens, and potential nephrotoxic agents. In the final analysis, 12 articles (n = 1,108 patients), consisting of 24 distinct TBI/chemotherapy conditioning regimens were included. Regimens were divided into three subgroups: adults (age > or =18 years), children (age <18 years), and mixed population (both adults and children). Multivariate logistic regression was performed to identify dosimetric and chemotherapeutic factors significantly associated with late renal complications.

RESULTS

Individual analysis was performed on each population subgroup. For the purely adult population, the only significant variable was total dose. For the mixed population, the significant variables included total dose, dose rate, and the use of fludarabine. For the pediatric population, only the use of cyclosporin or teniposide was significant; no dose response was noted. A logistic model was generated with the exclusion of the pediatric population because of its lack of dose response. This model yielded the following significant variables: total dose, dose rate, and number of fractions.

CONCLUSION

A dose response for renal damage after TBI was identified. Fractionation and low dose rates are factors to consider when delivering TBI to patients undergoing bone marrow transplantation. Drug therapy also has a major impact on kidney function and can modify the dose-response function.

Long-Term Outcome After Static Intensity-Modulated Total Body Radiotherapy Using Compensators Stratified by Pediatric and Adult Cohorts

PURPOSE

To report the long-term outcome after total body irradiation with intensity-modulating compensators and allogeneic/autologous transplantation, especially in terms of therapy-related toxicity in pediatric and adult cohorts.

METHODS AND MATERIALS

A total of 257 consecutive patients (40 children and 217 adults) have been treated since 1983 with TBI using static intensity-modulated radiotherapy for hematologic malignancies. The total dose of 12 Gy was applied in six fractions within 3 days before allogeneic (n = 174) or autologous (n = 83) transplantation. The median follow-up was 9.2 years.

RESULTS

The 5-year overall survival rate was 47.9% (49.8% for the adults and 37.5% for the children, p = 0.171). The 5-year tumor-related mortality rate was 23%, and the 5-year treatment-related mortality rate 29.2% (29.5% in the adults and 27.5% in the pediatric patients). Interstitial pneumonitis developed in 28 (10.9%) of 257 patients and in 12.5% of the pediatric cohort. The interstitial pneumonitis rate was 25% in pediatric patients treated with a 12-Gy lung dose compared with 4.2% for those treated to an 11-Gy lung dose. The overall survival rate stratified by lung dose was 26.7% for 12 Gy and 52.4% for 11 Gy (p = 0.001). The incidence of veno-occlusive disease and cataract was 5.8% and 6.6% in all patients and 12.5% and 15% in the pediatric patients, respectively (p < 0.05). Secondary malignancies were found in 4.3% of all patients, all in the adult cohort at transplantation.

CONCLUSION

Static intensity-modulated total body irradiation with a total dose of 12 Gy before allogeneic/autologous transplantation is a successful treatment with good long-term outcome and acceptable therapy-related toxicities. Constraining the lung dose to 11 Gy substantially lowered the actuarial treatment-related mortality. This effect was especially striking in the pediatric patients.

Allogeneic hematopoietic cell transplantation (HCT) in Hurler's syndrome using a reduced intensity preparative regimen

Allogeneic hematopoietic cell transplantation (HCT) in patients with Hurler's syndrome can improve survival and ameliorate many aspects of Hurler's syndrome including neurologic decline and cardiac compromise. Unfortunately, the toxicity of traditional preparative regimens to organs affected by the syndrome may have deleterious effects. Additionally, despite the intensity of these regimens, achieving stable donor chimerism can be difficult. We report transplant outcomes following a reduced intensity, highly immunosuppressive preparative regimen consisting of alemtuzumab, fludarabine and melphalan prior to HCT in seven patients with Hurler's syndrome treated at two centers. Six patients received grafts from unrelated donors and one received a sibling donor graft. The preparative regimen was well tolerated. All patients had initial donor engraftment at 100 days; one patient had delayed loss of donor chimerism. There was no severe acute GVHD (no GI GVHD of grade II or more, no grade IV skin GVHD). Six of the seven children are surviving at a median of 1014 (726-2222) days post transplant. This reduced intensity preparative regimen has the potential to support engraftment and improve survival and outcome in patients with Hurler's syndrome undergoing HCT.

Pulmonary complications of haematopoietic cell transplantation in children

Paediatric haematopoietic cell transplantation has experienced significant advances in the last few decades. However, pulmonary complications are an important limitation to the efficacy of this intervention, contributing to post-transplantation morbidity and mortality. Such complications persist even in experienced centres and occur in adult and paediatric recipients. This review identifies the paediatric pulmonary complications that are commonly seen following haematopoietic cell transplantation and addresses both infectious and non-infectious aetiologies and their clinical manifestations, evaluation, and potential therapy. Ultimately, improvement in outcomes will require attention to immunosuppression as well as traditional diagnostic procedures and treatment. This article aims to review the current state of pulmonary complications post-transplantation, to examine the impact of our recent advances and changes in treatment, and to identify potential future therapies and hypothesise what role these might have on long-term survival.

Pretransplant Conditioning in Adults and Children: Dose Assurance With Intravenous Busulfan

PURPOSE/OBJECTIVES

To provide clinical insights into dosing and administration of IV busulfan, a conditioning agent for hematopoietic stem cell transplantation (HSCT).

DATA SOURCES

Review of published literature related to busulfan pretransplant conditioning using MEDLINE. Meeting abstracts, investigational protocols, and pharmaceutical manufacturers' package inserts also were reviewed.

DATA SYNTHESIS

Busulfan is an effective myeloablative conditioning agent for HSCT. The IV formulation increases dose assurance and the ability to target a therapeutic window. Therapeutic drug monitoring ensures that targeted blood levels are achieved, especially in children, thereby preventing underdosing, which can lead to disease progression or rejection, as well as overdosing, which can cause an increased risk of toxic side effects.

CONCLUSIONS

IV busulfan is a convenient, safe, and effective conditioning agent used in HSCT that has a predictable pharmacokinetic profile.

IMPLICATIONS FOR NURSING

An understanding of the pharmacokinetic principles underlying the relationship between the therapeutic window for busulfan and optimal HSCT outcomes will facilitate proper dosing and administration of IV busulfan.

Renal dysfunction after total body irradiation: dose-effect relationship

PURPOSE

Late complications related to total body irradiation (TBI) as part of the conditioning regimen for hematopoietic stem cell transplantation have been increasingly noted. We reviewed and compared the results of treatments with various TBI regimens and tried to derive a dose-effect relationship for the endpoint of late renal dysfunction. The aim was to find the tolerance dose for the kidney when TBI is performed.

METHODS AND MATERIALS

A literature search was performed using PubMed for articles reporting late renal dysfunction. For intercomparison, the various TBI regimens were normalized using the linear-quadratic model, and biologically effective doses (BEDs) were calculated.

RESULTS

Eleven reports were found describing the frequency of renal dysfunction after TBI. The frequency of renal dysfunction as a function of the BED was obtained. For BED>16 Gy an increase in the frequency of dysfunction was observed.

CONCLUSIONS

The tolerance BED for kidney tissue undergoing TBI is about 16 Gy. This BED can be realized with highly fractionated TBI (e.g., 6x1.7 Gy or 9x1.2 Gy at dose rates>5 cGy/min). To prevent late renal dysfunction, the TBI regimens with BED values>16 Gy (almost all found in published reports) should be applied with appropriate shielding of the kidneys.

The Importance of Age, Fludarabine, and Total Body Irradiation in the Incidence and Severity of Chronic Renal Failure after Allogeneic Hematopoietic Cell Transplantation

Nonmalignant late effects, including chronic renal failure (CRF), impair the quality of life of long-term survivors after allogeneic hematopoietic cell transplantation. One of the major risk factors is the use of total body irradiation (TBI) in the preparative regimen; TBI is currently fractionated in an attempt to reduce toxicity. We analyzed 241 patients who had TBI-based preparative regimens for allogeneic hematopoietic cell transplantation. TBI was delivered as a single fraction of 7.5 Gy (7.5S group), 12 Gy in 6 fractions (12F group), or 14.4 Gy in 8 fractions (14.4F group). The cumulative incidence of CRF at 2 years was 12%. Statistical analysis revealed that older age (P < .001) and fludarabine administration (P = .016) had a significant effect on the incidence of CRF. Furthermore, single-fraction TBI was also significantly associated with CRF severity, because 7 (6.3%) of 111 patients in the 7.5S group developed severe CRF, as opposed to 1 (0.8%) of 130 patients in the 12F and 14.4F groups combined (P = .044). However, these conclusions should be regarded as preliminary in view of the retrospective and nonrandomized nature of this study.

Neuropsychological resiliency after treatment for advanced stage neuroblastoma

The purpose of this study was to describe the neuropsychological functioning of survivors of advanced stage neuroblastoma. In all, 16 survivors, diagnosed at a median of 2.8 years, who had received intensive chemotherapy and surgical treatments, were identified; 11 had received myeloablative consolidation therapy, eight with total body irradiation (TBI). All patients were evaluated with a neuropsychological assessment battery at a median age of 8.8 years. Analyses included comparison of the performances of the TBI group vs the no-TBI group; determination of whether the proportion of individuals with impaired or superior performance on each measure exceeded normative expectations; and performance indexes reflecting patterns of performance. Results indicate no significant deleterious impact of TBI and/or presence or absence of myeloablative therapy on neurocognitive and neurobehavioral functioning. For this cohort, resilience to neuropsychological vulnerability was observed, which included the emergence of a profile of full-scale IQ, verbal IQ, and mathematical achievement well above average expectations. We concluded that the results document a lack of neuropsychological morbidity among this cohort of survivors of advanced stage neuroblastoma, regardless of the inclusion of TBI. Moreover, a striking pattern of excellent neurocognitive functioning with intact neurobehavioral functioning was observed.

Comparison of 100-day mortality rates associated with i.v. busulfan and cyclophosphamide vs other preparative regimens in allogeneic bone marrow transplantation for chronic myelogenous leukemia: Bayesian sensitivity analyses of confounded treatment and center effects

We evaluated the 100-day mortality rates associated with busulfan-based myeloablative conditioning regimens based on data from 1812 chronic myelogenous leukemia patients who underwent allogeneic blood or marrow transplantation (allotx). In all, 47 patients received intravenous (i.v.) busulfan and cyclophosphamide (i.v.BuCy2) with allotx at MD Anderson Cancer Center (MDACC) during 1995-1999. The remaining 1765 patients, whose data were supplied by the International Bone Marrow Transplant Registry (IBMTR), received alternative preparative regimens, primarily Cy-total body irradiation ( approximately 45%) or oral BuCy ( approximately 35%) during 1997-1998. As patients were not randomized between conditioning regimens, the i.v.BuCy2-versus-alternative treatment effect is confounded with a possible center effect due to nontreatment differences associated with factors differing between MDACC and the IBMTR centers. Additional complications are that the i.v.BuCy2-MDACC patients all survived 100 days, and three prognostic subgroups were included. Bayesian sensitivity analyses were performed to assess treatment effect on the probability of 100-day mortality, over a range of possible MDACC-versus-IBMTR center effects. For these patients, the posterior probability that i.v.BuCy2 was superior to alternative conditioning regimens ranges from 0.54 to 0.99, depending on prognosis and the magnitude of the assumed center effect.

Successful Unrelated Cord Blood Transplantation Using a Reduced-Intensity Conditioning Regimen in a 6-Month-Old Infant with Congenital Neutropenia Complicated by Severe Pneumonia

Here we report the first successful unrelated cord blood transplantation (CBT) using reduced-intensity conditioning for the 'treatment of congenital neutropenia in a 6-month-old infant with complications of severe pneumonia probably due to Staphylococcus aureus infection. Because the patient showed no response to treatment with granulocyte colony-stimulating factor and had a cytogenetic aberration, unrelated CBT with an HLA-DRB1 genotypic mismatch was performed. The number of infused cells was 15 x 10(7)/kg. The preparative regimen was fludarabine, cyclophosphamide, and 6 Gy of total body irradiation. Teicoplanin was administered for bacterial pneumonia. Neutrophil engraftment was achieved on day 41 and was followed by clinical improvement. The patient gradually caught up on growth and development after the CBT. Unrelated CBT using a reduced-intensity conditioning regimen may be an effective treatment for congenital neutropenia.