Long-term risk of second malignant neoplasms after neuroblastoma in childhood: Role of treatment

Long-Term Risk of Subsequent Neoplasms in 5-Year Survivors of Childhood Neuroblastoma: A Dutch Childhood Cancer Survivor Study-LATER 3 Study

PURPOSE

Neuroblastoma survivors have an increased risk of developing subsequent malignant neoplasms (SMNs), but the risk of subsequent nonmalignant neoplasms (SNMNs) and risk factors are largely unknown. We analyzed the long-term risks and associated risk factors for developing SMNs and SNMNs in a well-characterized cohort of 5-year neuroblastoma survivors.

METHODS

We included 563 5-year neuroblastoma survivors from the Dutch Childhood Cancer Survivor Study (DCCSS)-LATER cohort, diagnosed during 1963-2014. Subsequent neoplasms were ascertained by linkages with the Netherlands Cancer Registry and the Dutch Nationwide Pathology Databank (Palga) and medical chart review. We calculated standardized incidence ratios (SIRs), absolute excess risk (AER), and cumulative incidences. Multivariable competing risk regression analysis was used to evaluate risk factors.

RESULTS

In total, 23 survivors developed an SMN and 60 an SNMN. After a median follow-up of 23.7 (range, 5.0-56.3) years, the risk of SMN was elevated compared with the general population (SIR, 4.0; 95% CI, 2.5 to 5.9; AER per 10,000 person-years, 15.1). The 30-year cumulative incidence was 3.4% (95% CI, 1.9 to 6.0) for SMNs and 10.4% (95% CI, 7.3 to 14.8) for SNMNs. Six survivors developed an SMN after iodine-metaiodobenzylguanidine (131IMIBG) treatment. Survivors treated with 131IMIBG had a higher risk of developing SMNs (subdistribution hazard ratio [SHR], 5.7; 95% CI, 1.8 to 17.8) and SNMNs (SHR, 2.6; 95% CI, 1.2 to 5.6) compared with survivors treated without 131IMIBG; results for SMNs were attenuated in high-risk patients only (SMNs SHR, 3.6; 95% CI, 0.9 to 15.3; SNMNs SHR, 1.5; 95% CI, 0.7 to 3.6).

CONCLUSION

Our results demonstrate that neuroblastoma survivors have an elevated risk of developing SMNs and a high risk of SNMNs. 131IMIBG may be a treatment-related risk factor for the development of SMN and SNMN, which needs further validation. Our results emphasize the need for awareness of subsequent neoplasms and the importance of follow-up care.

Impact of risk-based therapy on late morbidity and mortality in neuroblastoma survivors: a report from the Childhood Cancer Survivor Study

BACKGROUND

Early efforts at risk-adapted therapy for neuroblastoma are predicted to result in differential late effects; the magnitude of these differences has not been well described.

METHODS

Late mortality, subsequent malignant neoplasms (SMNs), and severe/life-threatening chronic health conditions (CHCs), graded according to CTCAE v4.03, were assessed among 5-year Childhood Cancer Survivor Study (CCSS) survivors of neuroblastoma diagnosed 1987-1999. Using age, stage at diagnosis, and treatment, survivors were classified into risk groups (low [n = 425]; intermediate [n = 252]; high [n = 245]). Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) of SMNs were compared with matched population controls. Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals for CHC compared with 1029 CCSS siblings.

RESULTS

Among survivors (49.8% male; median age = 21 years, range = 7-42; median follow-up = 19.3 years, range = 5-29.9), 80% with low-risk disease were treated with surgery alone, whereas 79.1% with high-risk disease received surgery, radiation, chemotherapy ± autologous stem cell transplant (ASCT). All-cause mortality was elevated across risk groups (SMRhigh = 27.7 [21.4-35.8]; SMRintermediate = 3.3 [1.7-6.5]; SMRlow = 2.8 [1.7-4.8]). SMN risk was increased among high- and intermediate-risk survivors (SIRhigh = 28.0 [18.5-42.3]; SIRintermediate = 3.7 [1.2-11.3]) but did not differ from the US population for survivors of low-risk disease. Compared with siblings, survivors had an increased risk of grade 3-5 CHCs, particularly among those with high-risk disease (HRhigh = 16.1 [11.2-23.2]; HRintermediate = 6.3 [3.8-10.5]; HRlow = 1.8 [1.1-3.1]).

CONCLUSION

Survivors of high-risk disease treated in the early days of risk stratification carry a markedly elevated burden of late recurrence, SMN, and organ-related multimorbidity, whereas survivors of low/intermediate-risk disease have a modest risk of late adverse outcomes.

Autologous Stem-Cell Transplantation for High-Risk Neuroblastoma: Historical and Critical Review

Simple Summary

The original idea that providing higher doses of cytotoxic agents will result in higher rates of tumor cell killing was proposed in the 1980s. Preclinical data supported clinical testing. Advancements in bone marrow and peripheral stem-cell support technologies during the 1980s and 1990s allowed for clinical developments that permitted testing the higher dose hypothesis in oncology patients. The results of almost 20 years of clinical trials proved the linear relationship between dosing and clinical outcome to be mostly inaccurate. As a consequence, the adult oncology field abandoned high-dose chemotherapy strategies by the turn of the 21st century. Neuroblastoma is the only pediatric extracranial solid tumor where high-dose chemotherapy has remained part of the standard management for high-risk cases. This systematic review aims to understand the historical reason for such an exception and analyzes data challenging the benefit of high-dose chemotherapy and autologous stem-cell transplants in the era of anti-GD2 immunotherapy.

Abstract

Curing high-risk neuroblastoma (HR-NB) is a challenging endeavor, which involves the optimal application of several therapeutic modalities. Treatment intensity for cancer became highly appealing in the 1990s. Investigative trials assumed that tumor response correlated with the dosage or intensity of drug(s) administered, and that this response would translate into improved survival. It was postulated that, if myelotoxicity could be reversed by stem-cell rescue, cure might be possible by increasing the dose intensity of treatment. The principle supported autologous stem-cell transplant (ASCT) strategies. High-dose therapy transformed clinical practice, legislation, and public health policy, and it drove a two-decade period of entrepreneurial oncology. However, today, no ASCT strategies remain for any solid tumor indication in adults. As with most solid malignancies, higher dosing of cytotoxic agents has not resulted in a clear benefit in survival for HR-NB patients, whereas the long-term toxicity has been well defined. Fortunately, novel approaches such as anti-GD2 immunotherapy have demonstrated a significant survival benefit with a much less adverse impact on the patient’s wellbeing. On the basis of extensive experience, persisting with administering myeloablative chemotherapy as the standard to treat children with HR-NB is not consistent with the overall aim in pediatric oncology of curing with as little toxicity as possible.

Pediatric high risk neuroblastoma with autologous stem cell transplant - 20 years of experience

BACKGROUND AND OBJECTIVE

Neuroblastoma is the most common extracranial solid tumor found in pediatric patients. High-risk neuroblastoma (HR-NBL) can be characterized by metastasis, age, and other tumor characteristics that result in an adverse outlook for this patient cohort. The standard of care includes induction chemotherapy, surgery, followed by stem cell autologous transplant (ASCT), and later, antidisialoganglioside (anti-GD2) antibodies. In this study, we provide the survival and toxicity data of our HR-NBL patients treated with a single ASCT.

METHODS

We retrospectively analyzed pediatric HR-NBL patients treated with single ASCT after a carboplatin, etoposide, and melphalan (CEM) regimen in our institution between January 1993 and December 2014.

RESULTS

There were 99 evaluable patients with male predominance. The median age at diagnosis was 3 years. Most of our HR-NBL patients were stage 4 (88%). All patients received ASCT. Peripheral blood was the graft source in 58% of the patients. Time for hematological count recovery with bone marrow as a graft source was prolonged but not statistically significant when compared with PBSCs. Of all the patients, 58% received radiation therapy to residual disease. Overt secondary leukemia was not seen in any of these patients. Three-year overall survival (OS) was 68.5% ± 5.2% and the 3-year event-free survival (EFS) was (48.3% ± 5.2%).

CONCLUSION

Our HR-NBL patients tolerated high-dose chemotherapy well followed by single autologous stem cell transplant. Tandem transplant is a feasible option in our patient cohort. Apart from secondary solid tumors, there were no long-term complications seen.

Risk of developing second malignant neoplasms in patients with neuroblastoma: a population study of the US SEER database

BACKGROUND

Neuroblastoma is a common extracranial malignant tumor in children. Its main treatment modality is a combination of chemotherapy, radiotherapy, and surgery. Given the advances in chemotherapy regimens and the widespread use of bone marrow transplantation over the decades, there has been improvement in treatment efficacy, which has led to prolonged patient survival. Accordingly, long-term complications have become a growing concern among physicians and patients. This study aimed to analyze the survival rate of patients with neuroblastoma and the risk factors for developing second malignant neoplasms (SMNs).

METHODS

The SEER 18 Regs (1973-2015) and SEER 9 Regs (1973-2015) data of the surveillance, epidemiology, and end results (SEER) database of the US National Cancer Institute were adopted for survival and SMN analysis.

RESULTS

The 5-, 10-, and 20-year overall survival rates of patients with neuroblastoma were 67%, 65%, and 62%, respectively. Among 38 patients with neuroblastoma who presented with SMNs, those with abdomen as the primary site accounted for the majority (63.2%), followed by those with thorax (26.3%) and other sites (10.5%). SMNs occurred more commonly in non-specific neuroblastoma (incidence: 0.87%) than ganglioneuroblastoma (incidence: 0.3%). Compared with the general population, the risk of SMN is significantly higher (SIR = 4.36). The risk of developing SMNs was significantly higher in the digestive system (SIR = 7.29), bones and joints (SIR = 12.91), urinary system (SIR = 23.48), brain and other nervous systems (SIR = 5.70), and endocrine system (SIR = 5.84). Multivariate analysis revealed that the year of diagnosis (OR = 2.138, 95% CI = 1.634-2.797, p < 0.001) was the only independent risk factor for developing SMNs.

CONCLUSION

This study identifies the risk factor for developing SMNs in patients with neuroblastoma, which could facilitate individualized screening for high-risk patients, to allow early diagnosis and treatment of SMNs.

Risk of radiation-induced second malignant neoplasms from photon and proton radiotherapy in paediatric abdominal neuroblastoma

BACKGROUND AND PURPOSE

State-of-the-art radiotherapy modalities have the potential of reducing late effects of treatment in childhood cancer survivors. Our aim was to investigate the carcinogenic risk associated with 3D conformal (photon) radiation (3D-CRT), intensity modulated arc therapy (IMAT) and pencil beam scanning proton therapy (PBS-PT) in the treatment of paediatric abdominal neuroblastoma.

MATERIALS AND METHODS

The risk of radiation-induced second malignant neoplasm (SMN) was estimated using the concept of organ equivalent dose (OED) for eleven organs (lungs, rectum, colon, stomach, small intestine, liver, bladder, skin, central nervous system (CNS), bone, and soft tissues). The risk ratio (RR) between radiotherapy modalities and lifetime absolute risks (LAR) were reported for twenty abdominal neuroblastoma patients (median, 4y; range, 1-9y) historically treated with 3D-CRT that were also retrospectively replanned for IMAT and PBS-PT.

RESULTS

The risk of SMN due to primary radiation was reduced in PBS-PT against 3D-CRT and IMAT for most patients and organs. The RR across all organs ranged from 0.38 ± 0.22 (bladder) to 0.98 ± 0.04 (CNS) between PBS-PT and IMAT, and 0.12 ± 0.06 (rectum and bladder) to 1.06 ± 0.43 (bone) between PBS-PT and 3D-CRT. The LAR for most organs was within 0.01-1% (except the colon) with a cumulative risk of 21 ± 13%, 35 ± 14% and 35 ± 16% for PBS-PT, IMAT and 3D-CRT, respectively.

CONCLUSIONS

PBS-PT was associated with the lowest risk of radiation-induced SMN compared to IMAT and 3D-CRT in abdominal neuroblastoma treatment. Other clinical endpoints and plan robustness should also be considered for optimal plan selection.

Long-Term Outcome and Role of Biology within Risk-Adapted Treatment Strategies: The Austrian Neuroblastoma Trial A-NB94

Simple Summary

Neuroblastoma, the most common extracranial malignancy of childhood, shows a highly variable course of disease ranging from spontaneous regression or maturation into a benign tumor to an aggressive and intractable cancer in up to 60% of patients. To adapt treatment intensity, risk staging at diagnosis is of utmost importance. The A-NB94 trial was the first in Austria to stratify therapy intensity according to tumor staging, patient’s age, and MYCN amplification status, the latter being a biologic marker turning otherwise low-risk tumors into high-risk disease. Recent publications showed a prognostic impact of various genomic features including segmental chromosomal aberrations (SCAs). We retrospectively investigated the relevance of SCAs within this risk-adapted treatment strategy. The A-NB94 approach resulted in an excellent long-term survival for the majority of patients with acceptable long-term morbidity. An age- and stage-dependent frequency of SCAs was confirmed and SCAs should always be considered in future treatment decision making processes.

Abstract

We evaluated long-term outcome and genomic profiles in the Austrian Neuroblastoma Trial A-NB94 which applied a risk-adapted strategy of treatment (RAST) using stage, age and MYCN amplification (MNA) status for stratification. RAST ranged from surgery only to intensity-adjusted chemotherapy, single or multiple courses of high-dose chemotherapy (HDT) followed by autologous stem cell rescue depending on response to induction chemotherapy, and irradiation to the primary tumor site. Segmental chromosomal alterations (SCAs) were investigated retrospectively using multi- and pan-genomic techniques. The A-NB94 trial enrolled 163 patients. Patients with localized disease had an excellent ten-year (10y) event free survival (EFS) and overall survival (OS) of 99 ± 1% and 93 ± 2% whilst it was 80 ± 13% and 90 ± 9% for infants with stage 4S and for infants with stage 4 non-MNA disease both 83 ± 15%. Stage 4 patients either >12 months or ≤12 months but with MNA had a 10y-EFS and OS of 45 ± 8% and 47 ± 8%, respectively. SCAs were present in increasing frequencies according to stage and age: in 29% of localized tumors but in 92% of stage 4 tumors (p < 0.001), and in 39% of patients ≤ 12 months but in 63% of patients > 12 months (p < 0.001). RAST successfully reduced chemotherapy exposure in low- and intermediate-risk patients with excellent long-term results while the outcome of high-risk disease met contemporary trials.

Systemic treatment of malignant gastrointestinal neuroectodermal tumour after childhood neuroblastoma: chemotherapy in malignant gastrointestinal neuroectodermal tumour

Malignant gastrointestinal neuroectodermal tumour is an extremely rare neoplasm that arises in the wall of the small bowel, stomach or large bowel in young-aged and middle-aged adults. Histologically, it is generally characterized by monomorphic cells with clear cytoplasma, S-100 protein expression, and EWSR1 gene translocation. To the best of our knowledge, we describe for the first time, the case of a young woman with a diagnosis of metastatic gastrointestinal neuroectodermal tumour arising from ileum, who had a childhood adrenal neuroblastoma with liver, bone and lymph nodes metastasis, treated with four cycles of chemotherapy with the schedule CADO-CVP (CADO: cyclophosphamide 300 mg/m/day on days 1-5, vincristine 1,5 mg/m/day on days 1 and 5, and doxorubicin 60 mg/m/day on day 5; CVP: cisplatin 40 mg/m/day on days 1-5 and etoposide 100 mg/m/day on days 1-5) followed by right adrenal, kidney, lymph nodes and liver lesion resection, conditioning chemotherapy (melphalan-carmustine-teniposide), stem cells autologous transplantation and consecutively radiotherapy on the spine (T9 to L3) for a total of 30 Gy. For the second diagnosis of gastrointestinal neuroectodermal tumour with liver metastasis, she underwent ileal tumour resection and platinum-anthracycline based chemotherapy with initial shrinkage of liver metastasis. Unfortunately, despite the initial response and the following delivered therapies, she died for rapid progressive disease. Taking into account the late effects of past therapeutic modalities, a long-term surveillance of young child treated for neuroblastoma, is required to appreciate their overall risks of second malignancies.

PERIPHERAL SURFACE DOSE FROM A LINEAR ACCELERATOR: RADIOCHROMIC FILM EXPERIMENTAL MEASUREMENTS OF FLATTENING FILTER FREE VERSUS FLATTENED BEAMS

There is a growing interest in the use of flattening filter free (FFF) beams due to the shorter treatment times. The reduction of head scatter suggests a better radiation protection to radiotherapy patients, considering the expected decrease in peripheral surface dose (PSD). In this work, PSD of flattened (FF) and FFF-photon beams was compared. A radiochromic film calibration method to reduce energy dependence was used. PSD was measured at distances from 2 to 50 cm to the field border for different square field sizes, modifying relevant clinical parameters. Also, clinical breast and prostate stereotactic body radiotherapy (SBRT) plans were studied. For square beams, FFF PSD is lower compared with FF PSD (differences ranging from 3 to 64%) and 10 MV FFF yields to the lowest value, for distances greater than 5 cm. For SBRT plans, near and far away from the field border, there is a reduction of PSD for FFF-beams, but the behavior at intermediate distances should be checked depending on the case.

Radiotherapy for childhood cancer and subsequent thyroid cancer risk: a systematic review

Most of the pooled analyses and reviews reported an association between radiotherapy for childhood cancer and an increased thyroid cancer risk. Up to now this article presents the first systematic literature review on this association combined with a critical assessment of the methodological quality of the included articles. PubMed and Web of Science databases were searched for relevant articles until May 2016. We included peer-reviewed cohort and case-control studies that investigated an association between radiotherapy for childhood cancer and the occurrence of subsequent thyroid cancer. A systematic overview is presented for the included studies. We identified 17 retrospective cohort studies, and four nested case-control studies, representing 100,818 subjects. The age range at first cancer diagnosis was 0-25.2 years. Considerable variability was found regarding study sizes, study design, treatment strategies, dose information, and follow-up periods. 20 of the 21 identified studies showed increased thyroid cancer risks associated with childhood radiation exposure. The large majority showed an increased relative risk or odds ratio confirming the association between radiotherapy and thyroid cancer although the variation in results was large. Additionally to a pooled analysis that has been published recently, we systematically included 17 further studies, which allowed us to cover information from countries that were not covered by large-scale childhood cancer survivor studies. The methodological limitations of existing studies and inconsistencies in findings across studies yielded a large study heterogeneity, which made a detailed comparison of study results difficult. There is a need to strengthen standardisation for reporting.

Late Effects and Survivorship Issues in Patients with Neuroblastoma

Over the past two decades, marked progress has been made in understanding the biology of neuroblastoma; this has led to refined risk stratification and treatment modifications with resultant increasing 5-year survival rates for children with neuroblastoma. Survivors, however, remain at risk for a wide variety of potential treatment-related complications, or "late effects", which may lead to excess morbidity and premature mortality in this cohort. This review summarizes the existing survivorship literature on long-term health outcomes for survivors of neuroblastoma, focusing specifically on potential injury to the endocrine, sensory, cardiovascular, pulmonary, and renal systems, as well as survivors' treatment-related risk for subsequent neoplasms and impaired quality of life. Additional work is needed to assess the potential late effects of newer multimodality therapies with the aim of optimizing long-term medical and psychosocial outcomes for all survivors of neuroblastoma.

Thyroid cancer in adolescents and young adults

In adolescents and young adults, thyroid cancer accounts for 13% of all invasive neoplasms, being three times more frequent in females, but overdiagnosis and overtreatment are common. There are two therapeutic approaches, one radical and no longer preferred in all instances, and the other conservative. Permanent complications of surgery and metabolic irradiation can affect quality of life and carry an economic burden. The overall survival rate approaches 100% for patients with differentiated thyroid cancer regardless of the extent of treatment. Medullary thyroid carcinoma is a very different entity, occurring most frequently in the context of hereditary tumor susceptibility syndromes.

Second malignant neoplasms after childhood non-central nervous system embryonal tumours in North America: A population-based study

BACKGROUND

Few studies in North America have quantified the risks of second malignant neoplasms (SMNs) among survivors of childhood non-central nervous system (non-CNS) embryonal tumours due to their rarity. We aimed to investigate these risks by combining population-based data from the United States of America and Canada.

METHODS

We evaluated patients with childhood non-CNS embryonal tumours reported to the Surveillance Epidemiology and End Results program and eight Canadian cancer registries from 1969 to 2010. Standardised incidence ratio (SIR) and cumulative incidence of SMNs were calculated. Subgroup analyses were conducted by the type of first primary cancer, age at first primary diagnosis and follow-up duration.

FINDINGS

Of the 13,107 survivors, 190 SMNs were reported over 134,548 person-years of follow-up. The SIR for all SMNs combined was 6.4 (95% confidence interval [CI]: 5.5-7.4). Most site-specific SIRs were significantly increased, ranging from 36 (95% CI: 26-49) for bone and joint cancer to 3.1 (95% CI: 1.5-5.2) for brain tumour. The risk for second malignancies declined as the time elapsed from the first primary diagnosis and was less prominent for patients first diagnosed at age 1-4 years. Notably, rhabdomyosarcoma survivors had a higher risk for SMNs than those with other first primaries. The overall cumulative incidence of SMNs was 1.0% at 10 years, increasing to 2.2% at 20 years and 4.1% at 30 years.

INTERPRETATION

Survivors with childhood non-CNS embryonal tumours faced an increased risk for SMNs compared to the general population. The risk variations observed in different patient categories may help target prevention strategies in high-risk subgroups.

Comparison of effective radiation doses from X-ray, CT, and PET/CT in pediatric patients with neuroblastoma using a dose monitoring program

PURPOSE

We aimed to evaluate the use of a dose monitoring program for calculating and comparing the diagnostic radiation doses in pediatric patients with neuroblastoma.

METHODS

We retrospectively reviewed diagnostic and therapeutic imaging studies performed on pediatric patients with neuroblastoma from 2003 to 2014. We calculated the mean effective dose per exam for X-ray, conventional computed tomography (CT), and CT of positron emission tomography/computed tomography (PET/CT) from the data collected using a dose monitoring program (DoseTrack group) since October 2012. Using the data, we estimated the cumulative dose per person and the relative dose from each modality in all patients (Total group). The effective dose from PET was manually calculated for all patients.

RESULTS

We included 63 patients with a mean age of 3.2±3.5 years; 28 had a history of radiation therapy, with a mean irradiated dose of 31.9±23.2 Gy. The mean effective dose per exam was 0.04±0.19 mSv for X-ray, 1.09±1.11 mSv for CT, and 8.35±7.45 mSv for CT of PET/CT in 31 patients of the DoseTrack group. The mean estimated cumulative dose per patient in the Total group was 3.43±2.86 mSv from X-ray (8.5%), 7.66±6.09 mSv from CT (19.1%), 18.35±13.52 mSv from CT of PET/CT (45.7%), and 10.71±10.05 mSv from PET (26.7%).

CONCLUSION

CT of PET/CT contributed nearly half of the total cumulative dose in pediatric patients with neuroblastoma. The radiation dose from X-ray was not negligible because of the large number of X-ray images. A dose monitoring program can be useful for calculating radiation doses in patients with cancer.

Neuroblastoma survivors are at increased risk for second malignancies: A report from the International Neuroblastoma Risk Group Project

BACKGROUND

The incidence of second malignant neoplasm (SMN) within the first ten years of diagnosis in high-risk neuroblastoma patients treated with modern, intensive therapy is unknown. Further, the underlying germline genetics that contribute to SMN in these survivors are not known.

METHODS

The International Neuroblastoma Risk Group (INRG) database of patients diagnosed from 1990 to 2010 was analysed. SMN risk was accessed by cumulative incidence, standardised incidence ratios (SIRs) and absolute excess risk. A candidate gene-based association study evaluated genetic susceptibility to SMN in neuroblastoma survivors.

RESULTS

Of the 5987 patients in the INRG database with SMN data enrolled in a clinical trial, 43 (0.72%) developed a SMN. The 10-year cumulative incidence of SMN for high-risk patients was 1.8% (95% confidence interval [CI] 1.0-2.6%) compared with 0.38% (95% CI: 0.22-0.94%) for low-risk patients (P = 0.01). High-risk patients had an almost 18-fold higher incidence of SMN compared to age- and sex-matched controls (SIR = 17.5 (95% CI: 11.4-25.3), absolute excess risk = 27.6). For patients treated on high- and intermediate-risk clinical trials, the SIR of acute myelogenous leukaemia was 106.8 (95% CI: 28.7-273.4) and 127.7 (95%CI: 25.7-373.3), respectively. Variants implicating DNA repair genes XRCC3 (rs861539: P = 0.006; odds ratio: 2.04, 95%CI: 1.19-3.46) and MSH2 (rs17036651: P = 0.009; odds ratio: 0.26, 95% CI: 0.08-0.81) were associated with SMN.

CONCLUSION

The intensive multi-modality treatment strategy currently used to treat high-risk neuroblastoma is associated with a significantly increased risk of secondary acute myelogenous leukaemia. Defining the interactions of treatment exposures and genetic factors that promote the development of SMN is critical for optimising survivorship care.

Incidence and risk factors for secondary malignancy in patients with neuroblastoma after treatment with (131)I-metaiodobenzylguanidine

Several reports of second malignant neoplasm (SMN) in patients with relapsed neuroblastoma after treatment with (131)I-MIBG suggest the possibility of increased risk. Incidence of and risk factors for SMN after (131)I-MIBG have not been defined. This is a multi-institutional retrospective review of patients with neuroblastoma treated with (131)I-MIBG therapy. A competing risk approach was used to calculate the cumulative incidence of SMN from time of first exposure to (131)I-MIBG. A competing risk regression was used to identify potential risk factors for SMN. The analytical cohort included 644 patients treated with (131)I-MIBG. The cumulative incidence of SMN was 7.6% (95% confidence interval [CI], 4.4-13.0%) and 14.3% (95% CI, 8.3-23.9%) at 5 and 10 years from first (131)I-MIBG, respectively. No increase in SMN risk was found with increased number of (131)I-MIBG treatments or higher cumulative activity per kilogram of (131)I-MIBG received (p = 0.72 and p = 0.84, respectively). Thirteen of the 19 reported SMN were haematologic. In a multivariate analysis controlling for variables with p < 0.1 (stage, age at first (131)I-MIBG, bone disease, disease status at time of first (131)I-MIBG), patients with relapsed/progressive disease had significantly lower risk of SMN (subdistribution hazard ratio 0.3, 95% CI, 0.1-0.8, p = 0.023) compared to patients with persistent/refractory neuroblastoma. The cumulative risk of SMN after (131)I-MIBG therapy for patients with relapsed or refractory neuroblastoma is similar to the greatest published incidence for high-risk neuroblastoma after myeloablative therapy, with no dose-dependent increase. As the number of patients treated and length of follow-up time increase, it will be important to reassess this risk.

Concurrent Presentation of Therapy Related Acute Myeloid Leukemia in a Case of Neuroblastoma

Therapy related Acute Myeloid Leukemia/Myelodysplastic syndrome (t-AML/MDS) occur due to the direct mutational events of the chemotherapeutic agents and radiotherapy. The disease latency, mutational events and prognosis vary with the type of chemotherapeutic agent. Therapy related Acute Myeloid Leukemia occurring with DNA topoisomerase II inhibitors have a shorter latency period and poor prognosis than anthracyclin based regimens. We report a case of a 9 year old boy who developed t-AML with mixed-lineage-leukemia gene translocation within a year of high dose chemotherapy for stage 4 neuroblastoma. He had residual mass of neuroblastoma in the abdomen and bone marrow. The patient expired within 2 weeks of induction chemotherapy.

The association between breast cancer and thyroid cancer: a meta-analysis

Previous studies have suggested an association between breast cancer and thyroid cancer; however, there has not been a formal meta-analysis which collates the existing evidence supporting the hypothesis that breast cancer or thyroid cancer predisposes an individual to developing the other. A systematic search was carried out using PubMed and Medline. We searched for articles containing epidemiological evidence of breast cancer following thyroid cancer and vice versa. Additionally, we searched for articles that included epidemiological data involving the incidence of all second primary malignancies (SPMs) following both breast cancer and thyroid cancer, and compared the datasets. The meta-analysis performed in a total of 18 studies showed that there is a significantly increased risk of developing thyroid cancer as a second primary malignancy of breast cancer (SIR = 1.59, 95 % confidence interval (CI) 1.28-1.99). Additionally, there was marginally increased risk of developing breast cancer as a second primary malignancy of thyroid cancer (SIR = 1.24, 95 % CI 1.16-1.33), compared to the general risk of developing a second primary malignancy following thyroid cancer. The findings suggest that the risk of developing thyroid cancer as a second primary malignancy of breast cancer and vice versa is increased compared to the background risk of developing other SPMs. The risk of developing thyroid cancer after a primary breast cancer was higher than the risk of developing breast cancer as a second primary malignancy of thyroid cancer. This suggests that the effects of treatment-related factors and specific pathological processes of each cancer may contribute to the increased risk rather than common risk factors including genetic factors. Elucidation of the common mechanisms between breast cancer and thyroid cancer will have important implications in both diagnostic and therapeutic management of these cancers. Benefit of thyroid ultrasound screening after breast cancer surgery needs to be assessed.

The role of chest computed tomography (CT) as a surveillance tool in children with high-risk neuroblastoma

BACKGROUND

Standardization of imaging obtained in children with neuroblastoma is not well established. This study examines chest CT in pediatric patients with high-risk neuroblastoma.

PROCEDURE

Medical records and imaging from 88 patients with high-risk neuroblastoma, diagnosed at St. Jude Children's Research Hospital between January, 2002 and December, 2009, were reviewed. Surveillance imaging was conducted through 2013. Ten patients with thoracic disease at diagnosis were excluded. Event free survival (EFS) and overall survival (OS) were estimated. Size specific dose estimates for CT scans of the chest, abdomen, and pelvis were used to estimate absolute organ doses to 23 organs. Organ dosimetry was used to calculate cohort effective dose.

RESULTS

The 5 year OS and EFS were 51.9% ± 6.5% and 42.6% ± 6.5%, respectively. Forty-six (58.9%) patients progressed/recurred and 41 (52.6%) died of disease. Eleven patients (14%) developed thoracic disease progression/recurrence identified by chest CT (1 paraspinal mass, 1 pulmonary nodules, and 9 nodal). MIBG (metaiodobenzylguanidine) scans identified thoracic disease in six patients. Five of the 11 had normal chest MIBG scans; three were symptomatic and two were asymptomatic with normal chest MIBG scans but avid bone disease. The estimated radiation dose savings from surveillance without CT chest imaging was 42%, 34% when accounting for modern CT acquisition (2011-2013).

CONCLUSIONS

Neuroblastoma progression/recurrence in the chest is rare and often presents with symptoms or is identified using standard non-CT imaging modalities. For patients with non-thoracic high-risk neuroblastoma at diagnosis, omission of surveillance chest CT imaging can save 35-42% of the radiation burden without compromising disease detection.

Long-term side effects of radiotherapy for pediatric localized neuroblastoma : results from clinical trials NB90 and NB94

INTRODUCTION

Neuroblastoma (NB) is the most frequent indication for extracranial pediatric radiotherapy. As long-term survival of high-risk localized NB has greatly improved, we reviewed treatment-related late toxicities in pediatric patients who received postoperative radiotherapy (RT) for localized NB within two French prospective clinical trials: NB90 and NB94.

PATIENTS AND METHODS

From 1990-2000, 610 children were enrolled. Among these, 35 were treated with induction chemotherapy, surgery, and RT. The recommended RT dose was 24 Gy at ≤ 2 years, 34 Gy at > 2 years, ± a 5 Gy boost in both age groups.

RESULTS

The 22 patients still alive after 5 years were analyzed. The median follow-up time was 14 years (range 5-21 years). Late effects after therapy occurred in 73 % of patients (16/22), within the RT field for 50 % (11/22). The most frequent in-field effects were musculoskeletal abnormalities (n = 7) that occurred only with doses > 31 Gy/1.5 Gy fraction (p = 0.037). Other effects were endocrine in 3 patients and second malignancies in 2 patients. Four patients presented with multiple in-field late effects only with doses > 31 Gy.

CONCLUSION

After a median follow-up of 14 years, late effects with multimodality treatment were frequent. The most frequent effects were musculoskeletal abnormalities and the threshold for their occurrence was 31 Gy.

Second malignancies in patients with neuroblastoma: the effects of risk-based therapy

BACKGROUND

To investigate the incidence of second malignant neoplasms (SMN) for patients with neuroblastoma, we analyzed patients from the SEER database according to three treatment eras (Era 1: 1973-1989, Era 2: 1990-1996, and Era 3: 1997-2006) corresponding to the introduction of multi-agent chemotherapy, risk-based treatment, and stem cell transplant.

PROCEDURES

The SEER database was mined for all patients with neuroblastoma or ganglioneuroblastoma. Cumulative incidence of SMN was calculated with death as a competing risk. A poisson regression model was used to estimate incidence rate ratios and 95% confidence intervals to compare the rates of SMN between patients in different Eras.

RESULTS

The analytic cohort included 2,801 patients. Thirty-four patients developed a SMN, accounting for 1.2% of all patients. Of the patients who developed a SMN, 47.1% received radiation for their primary neuroblastoma. Fourteen of the SMN were carcinomas, and 10 were hematologic malignancies, with six cases of acute myelogenous leukemia. There was no difference in the incidence of SMN in Era 1 compared to Era 3 (P = 0.48). The cumulative incidence of SMN at 30 years for high-risk patients was 10.44% (95% CI 3.98-20.52%) compared to 3.57% (95% CI 1.87-6.12%) for non-high-risk patients (P < 0.001).

CONCLUSIONS

This study showed no increase in the incidence of SMNs for children treated in the most recent treatment era as compared to earlier Eras. However, as the risk for developing SMN does not plateau, the number of SMNs will likely continue to rise in the cohort of patients treated after 1996. Comprehensive follow-up care for these survivors will be important.

Subsequent malignant neoplasms in pediatric patients initially diagnosed with neuroblastoma

BACKGROUND

Most prior studies evaluating subsequent malignant neoplasms (SMNs) in patients with neuroblastoma are restricted to long-term survivors and/or their treatment exposures. This study investigates SMNs in patients diagnosed with neuroblastoma at our institution.

METHODS

Records of 646 patients treated for neuroblastoma at St Jude Children's Research Hospital between 1961 and 2005 were reviewed. Data from patients with SMNs were analyzed and the 20- and 30-year cumulative incidence of SMNs and standardized incidence ratio were calculated.

RESULTS

Twenty-one patients had a SMN. The 20- and 30-year cumulative incidences of a SMN were 2.6%±0.7% and 4.6%±1.1%, respectively. The standardized incidence ratio was 8.3 (95% confidence interval, 5.0-13.0). Five patients developed a SMN within 5 years from diagnosis. The median latency for the development of acute myeloid leukemia/myelodysplastic syndrome (n=4), sarcomas (n=7), and carcinomas (n=5) were 3.6, 9, and 24.2 years, respectively. Nine patients died from their SMN, including all with acute myeloid leukemia/myelodysplastic syndrome.

CONCLUSIONS

Patients with neuroblastoma have an increased risk of secondary neoplasia. Modification of risk-adapted therapies will likely alter the affected patient population and the incidence of SMNs. Future studies are necessary to link SMNs to treatment exposures and to evaluate the risk of SMNs beyond 30 years from diagnosis.

Secondary malignant neoplasms after high-dose chemotherapy and autologous stem cell rescue for high-risk neuroblastoma

BACKGROUND

Outcomes for high-risk neuroblastoma remain poor. Modern treatment protocols utilizing intense induction followed by myeloablative consolidation chemotherapy with autologous stem cell rescue (ASCR) have improved survival rates, but the long-term sequelae, including development of secondary malignant neoplasms (SMN), are just now surfacing.

METHODS

We retrospectively reviewed data from 87 patients with high-risk neuroblastoma who were treated with intensive induction chemotherapy followed by ASCR between January 1991 and July 2011 following one of two institutional protocols: Chicago Pilot 1 (CP1; n = 12) and Chicago Pilot 2 (CP2; n = 75).

RESULTS

The 15-year overall survival rate for all 87 patients was 33.9% (95% confidence interval [CI], 23.1-45.0%). The 10- and 15-year cumulative incidence of SMN was 16.5% (95%CI, 7.2-38.0%) and 34.2% (95%CI, 18.6-63.1%), respectively, without evidence of a plateau at 15 years. Six of the 10 patients (n = 2 in CP1 and n = 8 in CP2) who developed SMN had hematologic malignancies including acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS). Solid tumors included thyroid papillary carcinoma, chondrosarcoma, hepatocellular carcinoma, and biliary adenocarcinoma.

CONCLUSION

A significantly higher incidence of SMN, especially hematological malignancies, was observed in this cohort compared to older neuroblastoma studies, potentially due to exposure to epipodophyllotoxins and a high cumulative dose of alkylating agents these patients received. The risk of developing an SMN continued to increase with survival time and did not reach the plateau at 15 years. Although the number of the patients is relatively small, our study emphasizes the need for life-long follow-up of survivors who were treated using modern therapy.

Surgery combined with controlled-release doxorubicin silk films as a treatment strategy in an orthotopic neuroblastoma mouse model

Background:

Neuroblastoma tumour resection goal is maximal tumour removal. We hypothesise that combining surgery with sustained, local doxorubicin application can control tumour growth.

Methods:

We injected human neuroblastoma cells into immunocompromised mouse adrenal gland. When KELLY cell-induced tumour volume was >300 mm³, 80–90% of tumour was resected and treated as follows: instantaneous-release silk film with 100 μg doxorubicin (100IR), controlled-release film with 200 μg (200CR) over residual tumour bed; and 100 and 200 μg intravenous doxorubicin (100IV and 200IV). Tumour volume was measured and histology analysed.

Results:

Orthotopic tumours formed with KELLY, SK-N-AS, IMR-32, SH-SY5Y cells. Tumours reached 1800±180 mm³ after 28 days, 2200±290 mm³ after 35 days, 1280±260 mm³ after 63 days, and 1700±360 mm³ after 84 days, respectively. At 3 days post KELLY tumour resection, tumour volumes were similar across all groups (P=0.6210). Tumour growth rate was similar in untreated vs control film, 100IV vs 100IR, and 100IV vs 200IV. There was significant difference in 100IR vs 200CR (P=0.0004) and 200IV vs 200CR (P=0.0003). Tumour growth with all doxorubicin groups was slower than that of control (P: <0.0001–0.0069). At the interface of the 200CR film and tumour, there was cellular necrosis, surrounded by apoptotic cells before reaching viable tumour cells.

Conclusions:

Combining surgical resection and sustained local doxorubicin treatment is effective in tumour control. Administering doxorubicin in a local, controlled manner is superior to giving an equivalent intravenous dose in tumour control.

Long-term follow-up of children with high-risk neuroblastoma: the ENSG5 trial experience

BACKGROUND

Therapy for high-risk neuroblastoma is intensive and multimodal, and significant long-term adverse effects have been described. The aim of this study was to identify the nature and severity of late complications of metastatic neuroblastoma survivors included in the ENSG5 clinical trial.

PROCEDURE

The trial protocol included induction chemotherapy (randomized "Standard" OPEC/OJEC vs. "Rapid" COJEC), surgery of primary tumor and high-dose melphalan with stem cell rescue. Two hundred and sixty-two children were randomized, 69 survived >5 years, and 57 were analyzed. Data were obtained from the ENSG5 trial database and verified with questionnaires sent to participating centers.

RESULTS

Median follow-up was 12.9 (6.9-16.5) years. No differences were found in late toxicities between treatment arms. Twenty-eight children (49.1%) developed hearing loss. Nine patients (15.8%) developed glomerular filtration rate <80 ml/min/1.73 m(2), but no cases of chronic renal failure were documented. Endocrine complications (28.1% of children) included mainly hypogonadism and delayed growth. Four children developed second malignancies, three of them 5 years after diagnosis: one osteosarcoma, one carcinoma of the parotid gland and one ependymoma. There were no hematological malignancies or deaths in remission.

CONCLUSIONS

This study analyzed a wide cohort of high-risk neuroblastoma survivors from a multi-institutional randomized trial and established the profile of long-term toxicity within the setting of an international clinical trial.

Treatment of chest wall osteosarcoma presenting as second primary after treatment of neuroblastoma

Only 2 cases of osteosarcoma as a second primary malignancy after neuroblastoma have been reported in the literature. We present a case of chest wall osteosarcoma that developed in a 14-year-old boy 7 years after completion of chemotherapy, autologous peripheral blood stem cell transplantation, radiation, and resection for stage 3, high-risk neuroblastoma. A biopsy of a painful chest wall mass arising from the right third rib diagnosed osteosarcoma. He went on to have preoperative chemotherapy followed by wide local excision and chest wall reconstruction. He then received additional chemotherapy. This case highlights the importance of close observation for second malignancies in this patient population.

Methodology for determining doses to in-field, out-of-field and partially in-field organs for late effects studies in photon radiotherapy

An important but little examined aspect of radiation dosimetry studies involving organs outside the treatment field is how to assess dose to organs that are partially within a treatment field; this question is particularly important for studies intended to measure total absorbed dose in order to predict the risk of radiogenic late effects, such as second cancers. The purpose of this investigation was therefore to establish a method to categorize organs as in-field, out-of-field or partially in-field that would be applicable to both conventional and modern radiotherapy techniques. In this study, we defined guidelines to categorize the organs based on isodose inclusion criteria, developed methods to assess doses to partially in-field organs, and then tested the methods by applying them to a case of intensity-modulated radiotherapy for hepatocellular carcinoma based on actual patient data. For partially in-field organs, we recommend performing a sensitivity test to determine whether potential inaccuracies in low-dose regions of the DVH (from the treatment planning system) have a substantial effect on the mean organ dose, i.e. >5%. In such cases, we suggest supplementing calculated DVH data with measured dosimetric data using a volume-weighting technique to determine the mean dose.

Paraganglioma, neuroblastoma, and a SDHB mutation: Resolution of a 30-year-old mystery

Familial paraganglioma/pheochromocytoma (PGL/PCC) is genetically heterogenous with mutations in three of the four subunits of the heterotetrameric mitochondrial complex II enzyme succinate dehydrogenase (SDH) being causally responsible for the majority of cases. In addition to PGL/PCC an array of non-paraganglial tumors have been described in affected individuals. We present a 30-year follow-up on the family of a deceased patient who synchronously developed malignant neuroblastoma (NBL), PCC, and renal cell carcinoma (RCC). Other family members with late onset disease have come to our attention, and molecular study revealed a mutation in the SDHB gene. Despite the embryologic relationship, NBL has been seen in only two previous patients with familial PGL/PCC, both with deletions of the SDHB gene. Review of the literature suggests the lack of a reported association between NBL and familial PGL/PCC may be an ascertainment bias. We further suggest that study of the SDH genes in NBL survivors who develop secondary solid tumors, particularly RCC, may correct this bias, and provide for more effective and comprehensive tumor screening in this patient population.

Long-term outcomes in survivors of neuroblastoma: a report from the Childhood Cancer Survivor Study

BACKGROUND

The 5-year survival rate for individuals with neuroblastoma is approaching 70%. Few data exist, however, on the long-term outcomes of these patients, who are often treated at a very young age.

METHODS

Outcome data were obtained for 954 5-year neuroblastoma survivors who were diagnosed in 1970-1986 and enrolled in the Childhood Cancer Survivor Study (CCSS). Late mortality, second malignant neoplasms, and chronic health conditions were analyzed in relation to treatment factors using Poisson regression models and their modification with generalized estimating equations. Neuroblastoma survivors were compared with a cohort of 3899 siblings of CCSS participants for risk of chronic health conditions and selected sociodemographic outcomes. All statistical tests were two-sided.

RESULTS

Six percent of patients died more than 5 years after their diagnosis (standardized mortality ratio = 5.6; 95% confidence interval [CI] = 4.4 to 6.9). The most common causes of death were disease recurrence (n = 43) and second malignant neoplasms (n = 13). The cumulative incidence of second malignant neoplasms was 3.5% at 25 years and 7.0% at 30 years after diagnosis. Compared with the sibling cohort, survivors had an increased risk of selected chronic health conditions (risk ratio [RR] = 8.3; 95% CI = 7.1 to 9.7) with a 20-year cumulative incidence of 41.1%. The most prevalent outcomes involved the neurological, sensory, endocrine, and musculoskeletal systems, with 20-year cumulative incidences of 29.8%, 8.6%, 8.3%, and 7.8%, respectively. Neuroblastoma survivors who were treated with multimodality therapy were more likely to develop a chronic health condition than survivors treated with surgery alone (RR = 2.2; 95% CI = 1.6 to 3.0). Neuroblastoma survivors were less likely than siblings to have ever been employed (P = .04) or to be married (P < .001) and had a lower personal income (P = .009).

CONCLUSIONS

Neuroblastoma survivors have an increased rate of mortality and second malignant neoplasms, relative to the age- and sex-comparable US population, and of chronic health conditions, relative to their siblings, which underscores the need for long-term medical surveillance.

Monte Carlo study shows no significant difference in second cancer risk between 6- and 18-MV intensity-modulated radiation therapy

PURPOSE

To evaluate the photon and neutron out-of-field dose equivalents from 6- and 18-MV intensity-modulated radiation therapy (IMRT) and to investigate the impact of the differences on the associated risk of induced second malignancy using a Monte Carlo model.

METHODS AND MATERIALS

A Monte Carlo model created with MCNPX was used to calculate the out-of-field photon dose and neutron dose equivalent from simulated IMRT of the prostate conducted at beam energies of 6 and 18MV. The out-of-field dose equivalent was calculated at the locations of sensitive organs in an anthropomorphic phantom. Based on these doses, the risk of secondary malignancy was calculated based on organ-, gender-, and age-specific risk coefficients for a 50-year-old man.

RESULTS

The Monte Carlo model predicted much lower neutron dose equivalents than had been determined previously. Further analysis illuminated the large uncertainties in the neutron dose equivalent and demonstrated the need for better determination of this value, which plays a large role in estimating the risk of secondary malignancies. The Monte Carlo calculations found that the differences in the risk of secondary malignancies conferred by high-energy IMRT versus low-energy IMRT are minimal and insignificant, contrary to prior findings.

CONCLUSIONS

The risk of secondary malignancy associated with high-energy radiation therapy may not be as large as previously reported, and likely should not deter the use of high-energy beams. However, the large uncertainties in neutron dose equivalents at specific locations within the patient warrant further study so that the risk of secondary cancers can be estimated with greater accuracy.

Embryonal rhabdomyosarcoma as a second malignancy following multimodal therapy for advanced-stage neuroblastoma

Second malignancy as a long-term complication in survivors of advanced-stage neuroblastoma is rare, but it is becoming recognized more frequently. We report an unusual case of a soft-tissue sarcoma developing within a retroperitoneal primary following previous extensive treatment for metastatic neuroblastoma using multimodality imaging including PET/CT.

Abdominal cancer during early childhood: a dosimetric comparison of proton beams to standard and advanced photon radiotherapy

PURPOSE

Evaluation of dosimetric benefits of advanced radiotherapy techniques for the treatment of abdominal lesions during early childhood.

PATIENTS AND METHODS

Treatment planning was performed for five Neuroblastoma (NBL) and four Wilms Tumor (WT) patients. Opposing fields (2F), photon intensity modulated radiotherapy (IMXT) and two proton techniques (passively scattered (PT) and scanned beams (IMPT)) were considered. Averaged dose-volume histograms, associated dosimetric parameters and a radiobiological model for the estimation of the therapy related carcinogenic effect were evaluated.

RESULTS

With respect to the 2F technique, both proton techniques enabled to reduce mean liver and kidney dose by 40-60%; Organ fractions irradiated at the level of the tolerance dose were reduced by 65% for kidneys and 75% for the liver in NBL patients and by additional 10% for WT patients. IMXT enabled to reduce parameters related to the steep high-dose gradient, e.g., V(15Gy) for the kidneys was reduced by a factor 2-3 compared to 2F. V(12Gy) was reduced by 40% in the liver. On the other side, the improvement of those parameters characterizing the low isodose domain was limited for IMXT. The risk for radiation-induced secondary cancer was doubled for IMXT and even more increased for PT if secondary neutrons were taken into account, while this risk remained the same or was reduced by IMPT with respect to 2F.

CONCLUSIONS

Proton beams improved all dosimetric parameters for NBL and WT patients compared to photon techniques. This improvement was limited for IMXT mainly to parameters related to the steep high-dose gradient. Further research is needed to minimize uncertainties for secondary cancer estimations.

Childhood thyroid cancers and radioactive iodine therapy: necessity of precautious radiation health risk management

One of the lessons from Chernobyl's legacy on health impact beyond 20 years is not only how to detect and treat the patients with radiation-associated thyroid cancers but how to follow up those who received radioactive iodine treatment repetitively after surgery in order to monitor any recurrence/worsening and also how to predict the risk of secondary primary cancers for their lifetime period. To evaluate the possibility of second primary tumors after radioactive iodine treatment, we reviewed the reports on risks from both external and internal radiation exposure, especially at high doses during childhood through an internet service of the National Library of Medicine and the National Institutes of Health, PubMed by the end of June, 2007, together with our own experience of Chernobyl childhood thyroid cancers. Children who were internally exposed after Chernobyl accident have a long-term risk of well differentiated thyroid cancers. Once they have disease, ironically radioactive iodine ablation is one of the useful therapies after surgical treatment. Elevated risks of solid cancers and leukemia have been found in radioiodine-treated patients, however, so far precious few reports from Chernobyl thyroid cancer patient were published. To reduce the adverse effects of radioactive iodine therapy on non-target tissues, recombinant human TSH has been applied and proved effective. Period of latency of second primary cancers may be very long. Therefore patients treated with high activities of radioactive iodine, especially children cases, should be carefully followed up during their whole lifespan.

A Monte Carlo model for out-of-field dose calculation from high-energy photon therapy

As cancer therapy becomes more efficacious and patients survive longer, the potential for late effects increases, including effects induced by radiation dose delivered away from the treatment site. This out-of-field radiation is of particular concern with high-energy radiotherapy, as neutrons are produced in the accelerator head. We recently developed an accurate Monte Carlo model of a Varian 2100 accelerator using MCNPX for calculating the dose away from the treatment field resulting from low-energy therapy. In this study, we expanded and validated our Monte Carlo model for high-energy (18 MV) photon therapy, including both photons and neutrons. Simulated out-of-field photon doses were compared with measurements made with thermoluminescent dosimeters in an acrylic phantom up to 55 cm from the central axis. Simulated neutron fluences and energy spectra were compared with measurements using moderated gold foil activation in moderators and data from the literature. The average local difference between the calculated and measured photon dose was 17%, including doses as low as 0.01% of the central axis dose. The out-of-field photon dose varied substantially with field size and distance from the edge of the field but varied little with depth in the phantom, except at depths shallower than 3 cm, where the dose sharply increased. On average, the difference between the simulated and measured neutron fluences was 19% and good agreement was observed with the neutron spectra. The neutron dose equivalent varied little with field size or distance from the central axis but decreased with depth in the phantom. Neutrons were the dominant component of the out-of-field dose equivalent for shallow depths and large distances from the edge of the treatment field. This Monte Carlo model is useful to both physicists and clinicians when evaluating out-of-field doses and associated potential risks.

A Monte Carlo model for calculating out-of-field dose from a varian 6 MV beam

Dose to the patient outside of the treatment field is important when evaluating the outcome of radiotherapy treatments. However, determining out-of-field doses for any particular treatment plan currently requires either time-consuming measurements or calculated estimations that may be highly uncertain. A Monte Carlo model may allow these doses to be determined quickly, accurately, and with a great degree of flexibility. MCNPX was used to create a Monte Carlo model of a Varian Clinac 2100 accelerator head operated at 6 MV. Simulations of the dose out-of-field were made and measurements were taken with thermoluminescent dosimeters in an acrylic phantom and with an ion chamber in a water tank to validate the Monte Carlo model. Although local differences between the out-of-field doses calculated by the model and those measured did exceed 50% at some points far from the treatment field, the average local difference was only 16%. This included a range of doses as low as 0.01% of the central axis dose, and at distances in excess of 50 cm from the central axis of the treatment field. The out-of-field dose was found to vary with field size and distance from the central axis, but was almost independent of the depth in the phantom except where the dose increased substantially at depths less than dmax. The relationship between dose and kerma was also investigated, and kerma was found to be a good estimate of dose (within 3% on average) except near the surface and in the field penumbra. Our Monte Carlo model was found to well represent typical Varian 2100 accelerators operated at 6 MV.

Therapy-related acute myeloid leukemia in a child with Noonan syndrome and clonal duplication of the germline PTPN11 mutation

A 4-year-old girl with Noonan syndrome (NS) and constitutive PTPN11 mutation presented with stage 4 neuroblastoma and was treated by intensive chemotherapy. During the treatment, cytogenetic analysis revealed the development of a hyperdiploid clone with duplication of the germline PTPN11 mutation in a morphologically normal bone marrow. A few months later, the patient developed acute myelomonoblastic leukemia with an additional clonal deletion of 7q. Although, we cannot conclude whether there is an association between NS and neuroblastoma, this case suggests that duplication of germline PTPN11 mutations, potentially induced by chemotherapy, contributes to leukemogenesis in patients with NS.

High-risk neuroblastoma treated with tandem autologous peripheral-blood stem cell-supported transplantation: long-term survival update

PURPOSE

To provide an update on long-term survival of patients with high-risk neuroblastoma treated with tandem cycles of myeloablative therapy and peripheral-blood stem-cell rescue (PBSCR).

PATIENTS AND METHODS

Ninety-seven patients with high-risk neuroblastoma were treated between 1994 and 2002. Patients underwent induction therapy with five cycles of standard agents, resection of the primary tumor and local radiation, and two consecutive courses of myeloablative therapy (including total-body irradiation) with PBSCR.

RESULTS

Fifty-one patients have experienced relapse or died. Median follow-up time among the 46 patients who remain alive without progression is 5.6 years (range, 15.1 months to 9.9 years). Progression-free survival (PFS) rate at 5 years from diagnosis was 47% (95% CI, 36% to 56%), and PFS rate at 7 years was 45% (95% CI, 34% to 55%). Overall survival rate was 60% (95% CI, 48% to 69%) and 53% (95% CI, 40% to 64%) at 5 and 7 years, respectively. The 5- and 7- year PFS rates from time of first transplantation for 82 patients who completed both transplants were 54% (95% CI, 42% to 64%) and 52% (95% CI, 40% to 63%), respectively. Five patients died from treatment-related toxicity after tandem transplantation. Relapse occurred in 37 (42%) of 89 patients, mainly within 3 years of transplantation and primarily in diffuse osseous sites. No primary CNS relapse or secondary leukemia was seen. One patient developed synovial cell sarcoma 8 years after therapy.

CONCLUSION

High-dose therapy with tandem autologous stem-cell rescue is effective for treating high-risk neuroblastoma, with encouraging long-term survival. CNS relapse and secondary malignancies are rare after this therapy.

Malignant transformation and new primary tumours after therapeutic radiation for benign disease: substantial risks in certain tumour prone syndromes

In recent years the use of radiation treatment for benign tumours has increased with the advent of stereotactic delivery and, in particular, single high dose gamma knife therapy. This has been particularly true for benign CNS (central nervous system) tumours such as vestibular schwannoma, meningioma, pituitary adenoma, and haemangioblastoma. While short term follow up in patients with isolated tumours suggests this treatment is safe, there are particular concerns regarding its use in childhood and in tumour predisposing syndromes. We have reviewed the use of radiation treatment in these contexts with particular regard to malignant transformation and new tumour induction. This review indicates that much more caution is warranted regarding the use of radiation treatment for benign tumours in childhood and in tumour prone conditions such as the neurofibromatoses.