Risks of Spinal Abnormalities and Growth Impairment After Radiation to the Spine in Childhood Cancer Survivors: A PENTEC Comprehensive Review.

PURPOSE: A PENTEC (Pediatric Normal Tissue Effects in the Clinic) review was performed to estimate the dose-volume effects of radiation therapy on spine deformities and growth impairment for patients who underwent radiation therapy as children. METHODS AND MATERIALS: A systematic literature search was performed to identify published data for spine deformities and growth stunting. Data were extracted from 12 reports of children irradiated to the spine (N = 603 patients). The extracted data were analyzed to find associations between complication risks and the radiation dose (conventional fractionation throughout) as impacted by exposed volumes and age using the mixed-effects logistic regression model. When appropriate, corrections were made for radiation modality, namely orthovoltage beams. RESULTS: In the regression analysis, the association between vertebral dose and scoliosis rate was highly significant (P < .001). Additionally, young age at time of radiation was highly predictive of adverse outcomes. Clinically significant scoliosis can occur with doses ≥15 Gy to vertebrae during infancy (<2 years of age). For children irradiated at 2 to 6 years of age, overall scoliosis rates of any grade were >30% with doses >20 Gy; grade 2 or higher scoliosis was correlated with doses ≥30 Gy. Children >6 years of age remain at risk for scoliosis with doses >30 Gy; however, most cases will be mild. There are limited data regarding the effect of dose gradients across the spine on degree of scoliosis. The risk of clinically meaningful height loss was minimal when irradiating small volumes of the spine up to 20 Gy (eg, flank irradiation), except in infants who are more vulnerable to lower doses. Growth stunting was more frequent when larger segments of the spine (eg, the entire spine or craniospinal irradiation) were irradiated before puberty to doses >20 Gy. The effect was modest when patients were irradiated after puberty to doses >20 Gy. CONCLUSIONS: To reduce the risk of kyphoscoliosis and growth impairment, the dose to the spine should be kept to <20 Gy for children <6 years of age and to <10 to 15 Gy in infants. The number of vertebral bodies irradiated and dose gradients across the spine should also be limited when possible.

Increased Risk for Ipsilateral Breast Tumor Recurrence in Invasive Lobular Carcinoma after Accelerated Partial Breast Irradiation Brachytherapy.

BACKGROUND: The suitability criteria for accelerated partial breast irradiation (APBI) from the American Brachytherapy Society (ABS), American Society for Radiation Oncology (ASTRO), and The Groupe Européende Curiethérapie European SocieTy for Radiotherapy & Oncology (GEC-ESTRO) have significant differences. MATERIALS AND METHODS: This is a single institution retrospective review of 946 consecutive patients with invasive breast cancer who underwent lumpectomy and APBI intracavitary brachytherapy from 2003 to 2018. Overall survival (OS), breast cancer-specific survival (BCSS), relapse-free survival (RFS), and ipsilateral breast tumor recurrence (IBTR) were estimated with Kaplan-Meier method. RESULTS: Median follow-up time was 60.2 months. Median age was 68 years (46-94 years). The majority of patients had estrogen receptor (ER)-positive disease (94%). There were 821 (87%) cases of invasive ductal carcinoma and 68 cases (7%) of invasive lobular carcinoma (ILC). The 5-year OS, BCSS, RFS, and IBTR were 93%, 99%, 90%, and 1.5%, respectively. Upon univariate analysis, ILC (hazard ratio [HR], 4.6; p = .008) and lack of nodal evaluation (HR, 6.9; p = .01) were risk factors for IBTR. The 10-year IBTR was 2.5% for IDC and 14% for ILC. While the ABS and ASTRO criteria could not predict IBTR, the GEC-ESTRO intermediate risk group was associated with inferior IBTR (p = .04) when compared to both low risk and high risk groups. None of the suitability criteria was able to predict RFS. CONCLUSION: These results show that APBI is an effective treatment for patients with invasive breast cancer. Expansion of the current eligibility criteria should be considered, although prospective validation is needed. Caution is required when considering APBI for patients with ILC. IMPLICATIONS FOR PRACTICE: In a large retrospective review of 946 patients with early breast cancer treated with partial mastectomy and accelerated partial breast irradiation (APBI) intracavitary brachytherapy, this study demonstrates durable local control. Patients deemed unsuitable or high risk by the American Brachytherapy Society, American Society for Radiation Oncology, and European Society for Radiotherapy and Oncology guidelines were not at increased risk for ipsilateral breast tumor recurrence (IBTR), suggesting that expansion of the current criteria should be considered. Importantly, however, these results demonstrate that caution should be taken when considering APBI for patients with invasive lobular carcinoma, as these patients had relatively high risk for IBTR (10-year IBTR, 14%).

The Role of Radiation Therapy in the Older Patient.

PURPOSE OF REVIEW: Older patients represent a unique subgroup of the cancer patient population for which the role of radiation therapy (RT) requires special consideration. This review will discuss many of these considerations as well as various radiation treatment techniques in the context of a variety of disease sites. RECENT FINDINGS: Several recent studies give insight into the management of older cancer patients considering their age, performance status, comorbid conditions, quality of life, genetics, cost, and individual goals. RT plays an evolving and pivotal role in providing optimal care for this population. Recent advances in RT technique allow for more precise treatment delivery and reduced toxicity. Studies evaluating the use of radiation therapy in breast, brain, lung, prostate, rectal, pancreatic, esophageal, and oligometastatic cancer are summarized and discussed in the context of treating the older patient population. Individual age, performance and functional status, comorbid conditions, and patients' objectives and goals should all be considered when presenting treatment options for older patients and age alone should not disqualify patients from curative intent treatments. When possible, hypofractionated courses should be utilized as outcomes are often equivalent and toxicities are reduced. In many cases, RT may be preferable to other treatment options due to decreased toxicity profile and acceptable disease control.

Management of ductal carcinoma in situ with accelerated partial breast irradiation brachytherapy: Implications for guideline expansion.

PURPOSE: Accelerated partial breast irradiation (APBI) for patients with ductal carcinoma in situ (DCIS) is controversial, and the suitability criteria from the American Brachytherapy Society (ABS), American Society of Therapeutic Radiology and Oncology (ASTRO), and the European Society for Radiotherapy and Oncology (GEC-ESTRO) have important differences. METHODS AND MATERIALS: This is a single-institution retrospective review of 169 consecutive patients with DCIS who underwent lumpectomy followed by APBI intracavitary brachytherapy from 2003 to 2018. Outcomes, including overall survival, recurrence-free survival (RFS), ipsilateral breast tumor recurrence, and distant metastasis, were estimated with the Kaplan-Meier method. RESULTS: The median followup time was 62.5 months. Median age was 66 years (47-89 years). The majority of patients had estrogen receptor-positive disease (89%). Fifty patients (30%) had Grade 3 disease. Of the 142 patients with adequate pathology interpretation, 91 and 108 cases had margins ≥ 3 mm and ≥2 mm, respectively. Most patients (72%) were prescribed and started endocrine therapy. Of the patients evaluable for ABS criteria (N = 130), 97 met the suitability criteria. Of the patients evaluable for ASTRO criteria (N = 129), 42 were deemed cautionary and 33 were deemed unsuitable. Of the patients evaluable for GEC-ESTRO criteria (N = 143), 141 cases were at intermediate risk and two were at high risk. Five-year ipsilateral breast tumor recurrence, RFS, and overall survival were 0.6%, 97.7%, and 97.2%, respectively. The ABS, ASTRO, and GEC-ESTRO criteria failed to significantly predict for RFS. CONCLUSIONS: These results, although limited by short-term followup, indicate that expansion of the eligibility criteria of APBI for patients with DCIS should be considered.

The prevalence of luminal B subtype is higher in older postmenopausal women with ER+/HER2- breast cancer and is associated with inferior outcomes.

OBJECTIVES: To establish whether clinicopathologic and genomic characteristics may explain the poor prognosis associated with advanced age in ER+/HER2- breast cancer. MATERIALS AND METHODS: The cohort included 271 consecutive post-menopausal patients with ER+/HER2- invasive breast cancer ages 55 years and older. Patients were categorized as "younger" (ages 55- < 75) and "older" (ages ≥75). The Kaplan-Meier method was used to estimate locoregional recurrence (LRR), recurrence-free interval (RFi), and overall survival (OS). Gene expression of tumor samples was assessed with Affymetrix Rosetta/Merck Human RSTA microarray platform. Differential gene expression analysis of tumor samples was performed using R package Limma. RESULTS: 271 breast cancer patients were identified, including 186 younger and 85 older patients. Older patients had higher rates of Luminal B subtype (53% vs 34%) and lower rates of Luminal A subtype (42% vs 58%, p = 0.02). Older patients were less likely to receive chemotherapy (9% vs 40%, p < 0.001) and hormone therapy (71% vs 89%, p < 0.001). For cases of grade 1-2 disease, older patients had a higher proportion of the luminal B subtype (49% vs. 30%, p = 0.014). Age ≥ 75 predicted for inferior OS (HR = 3.06, p < 0.001). The luminal B subtype predicted for inferior OS (HR = 2.12, p = 0.014), RFi (HR 5.02, p < 0.001), and LRR (HR = 3.12, p = 0.045). There were no significant differences in individual gene expression between the two groups. CONCLUSION: Women with ER+/HER2- breast cancer ≥75 years old had higher rates of the more aggressive luminal B subtype and inferior outcomes. Genomic testing of these patients should be strongly considered, and treatment should be intensified when appropriate.

Health care disparities among octogenarians and nonagenarians with stage III lung cancer.

BACKGROUND: To the authors' knowledge, the practice patterns for patients aged more than 80 years with stage III non-small cell lung cancer (NSCLC) is not well known. The purpose of the current study was to investigate factors predictive of and the impact on overall survival (OS) after concurrent chemoradiation (CRT) among patients aged ≥80 years with American Joint Committee on Cancer stage III NSCLC in the National Cancer Data Base (NCDB). METHODS: In the NCDB, patients aged ≥80 years who were diagnosed with stage III NSCLC from 2004 to 2013 with complete treatment records were identified. Multivariable logistic regression and Cox proportional hazard models were generated and propensity score-matched analysis was used. RESULTS: A total of 12,641 patients met the entry criteria: 6018 (47.6%) had stage IIIA disease and 6623 (52.4%) had stage IIIB disease. The median age at the time of diagnosis was 83.0 years (range, 80-91 years). A total of 7921 patients (62.7%) received no therapy. Black race (odds ratio [OR], 1.23; 95% confidence interval [95% CI], 1.06-1.43) and living in a lower educated census tract of residence (OR, 1.20; 95% CI, 1.03-1.40) were found to be associated with not receiving care, whereas treatment at an academic center (OR, 0.80; 95% CI, 0.70-0.92) was associated with receiving cancer-directed therapy. Receipt of no treatment (hazard ratio [HR], 2.69; 95% CI, 2.57-2.82) or definitive radiation alone (HR, 1.15; 95% CI, 1.07-1.24) compared with CRT was associated with worse OS. On propensity score matching, not receiving CRT was found to be associated with worse OS (HR, 1.58; 95% CI, 1.44-1.72). CONCLUSIONS: In this NCDB analysis, approximately 62.7% of patients aged ≥80 years with stage III NSCLC received no cancer-directed care. Black race and living in a lower educated census tract were associated with not receiving cancer-directed care. OS was found to be improved in patients receiving CRT. Cancer 2018;124:775-84. © 2018 American Cancer Society.

Whole lung irradiation in stage IV Wilms tumor patients: Thyroid dosimetry and outcomes.

PURPOSE: To report the thyroid dosimetry and long-term follow-up of childhood cancer survivors treated with whole lung irradiation (WLI) for Wilms tumor. METHODS: Twenty-eight patients with pulmonary metastases from Wilms tumor who underwent WLI from 2000 TO 2012 at a single institution were reviewed. Radiation dose to the thyroid gland in each case was calculated. Postradiation thyroid function test (TFT) results and management of thyroid function abnormalities were extracted from the medical records. RESULTS: Median age at treatment was 5 years (range: 1-9 years), and median follow-up time was 74.1 months (7.2-198.4). The male/female ratio was 1:1.8. Complete dosimetry data were available for 22 of the 28 patients receiving WLI. Mean thyroid volume was 3.3 cc (range: 1-6.8). The average mean and median mean dose to the thyroid was 6.7 and 7.1 Gy, respectively (range: 1.3-11.7 Gy). Average max dose to the thyroid was 12.4 Gy (range: 7.8-20.3 Gy). Two patients were found to have a thyroid stimulating hormone (TSH) above the normal range, managed with levothyroxine. Another patient was found to have an isolated elevation of TSH which normalized without treatment. A fourth patient was found to have an enlarged thyroid on examination with no palpable nodules or abnormal TFTs. CONCLUSIONS: Average mean dose to the thyroid gland was 6.7 Gy for this population of stage IV Wilms tumor patients. There was a low rate of thyroid dysfunction, but limited follow-up. Attention to blocking the thyroid gland as much as possible when designing radiation fields can potentially mitigate the risks of long-term thyroid effects.

Outcomes following proton therapy for pediatric ependymoma.

BACKGROUND: Proton therapy can reduce the low and intermediate radiation dose to uninvolved brain tissue in children with intracranial ependymomas, which may improve functional outcomes and reduce second malignancies in survivors. Accordingly, ependymoma has become the most common pediatric tumor treated with proton therapy, yet data on efficacy and toxicity are limited. MATERIAL AND METHODS: Between June 2007 and February 2017, 179 children (≤21 years old) with nonmetastatic grade II/III intracranial ependymoma received proton therapy at our institution. Median age, 3.5 years (range, 0.7-21); 58% were male. Most (66%) tumors were in the posterior fossa and classified as WHO grade III (67%). 27% underwent multiple operations to maximize the extent of resection; ultimately 85% had a gross total or near total tumor resection before radiotherapy. 33% received preradiation chemotherapy. Median radiation dose in children ≤3 years old, 54 Gy(RBE). Most (>90%) children over 3 years old received 59.4 Gy(RBE). Patient and treatment variables were assessed for correlation with disease control. RESULTS: Median follow-up, 3.2 years. 3-year local control, progression-free survival, and overall survival rates were 85%, 76%, and 90%, respectively. First site of progression was local, metastatic, or simultaneous in 14, 17 and 6 patients, respectively. On multivariate analysis, subtotal resection was associated with inferior local control (67% vs. 88%; p ≤ .01) and progression-free survival (59% vs. 79%; p < .05). Male sex was associated with inferior progression-free (67% vs. 87%; p< .05) and overall survival (84% vs. 99%; p < .01). The 3-year CTCAE grade 2 + brainstem toxicity rate was 5.5% (95% CI: 2.9-10.2), including 1 grade 5 toxicity. CONCLUSIONS: This series of proton therapy for pediatric intracranial ependymoma demonstrates disease control comparable to photon series without unexpected toxicity. Subtotal resection and male sex were associated with inferior disease control. Additional follow-up to quantify the expected reductions in late toxicity with proton therapy is ongoing.

Correlation of Acute and Late Brainstem Toxicities With Dose-Volume Data for Pediatric Patients With Posterior Fossa Malignancies.

PURPOSE: Radiation-induced brainstem toxicity after treatment of pediatric posterior fossa malignancies is incompletely understood, especially in the era of intensity modulated radiation therapy (IMRT). The rates of, and predictive factors for, brainstem toxicity after photon RT for posterior fossa tumors were examined. METHODS AND MATERIALS: After institutional review board approval, 60 pediatric patients treated at our institution for nonmetastatic infratentorial ependymoma and medulloblastoma with IMRT were included in the present analysis. Dosimetric variables, including the mean and maximum dose to the brainstem, the dose to 10% to 90% of the brainstem (in 10% increments), and the volume of the brainstem receiving 40, 45, 50, and 55 Gy were recorded for each patient. Acute (onset within 3 months) and late (>3 months of RT completion) RT-induced brainstem toxicities with clinical and radiographic correlates were scored using Common Terminology Criteria for Adverse Events, version 4.0. RESULTS: Patients aged 1.4 to 21.8 years underwent IMRT or volumetric arc therapy postoperatively to the posterior fossa or tumor bed. At a median clinical follow-up period of 2.8 years, 14 patients had developed symptomatic brainstem toxicity (crude incidence 23.3%). No correlation was found between the dosimetric variables examined and brainstem toxicity. Vascular injury or ischemia showed a strong trend toward predicting brainstem toxicity (P=.054). Patients with grade 3 to 5 brainstem toxicity had undergone treatment to significant volumes of the posterior fossa. CONCLUSION: The results of the present series demonstrate a low, but not negligible, risk of brainstem radiation necrosis for pediatric patients with posterior fossa malignancies treated with IMRT. No specific dose-volume correlations were identified; however, modern treatment volumes might help limit the incidence of severe toxicity. Additional work investigating inherent biologic sensitivity might also provide further insight into this clinical problem.

Impact of lymph node evaluation in adjuvant and neoadjuvant chemotherapy settings on survival outcomes in Wilms tumour: a review of 185 cases from a single institution.

It is unclear if lymph node sampling in Wilms tumour, though critical for staging purposes, affects survival outcomes. The value of lymph node sampling in patients treated with neoadjuvant chemotherapy (NAC) is even more uncertain. We reviewed our institutional data to determine the impact of lymph node sampling on survival, as well as its role in the context of NAC. A total of 185 patients with Wilms tumour treated at our institution were included in this analysis. The number of nodes sampled (≤7, or >7), lymph node status (unknown, negative, or positive), pathological stage, and use of neoadjuvant chemotherapy were analysed for survival outcomes. Covariates were evaluated with chi-square test or Fisher's exact test where appropriate. All analyses were performed using SAS 9.3 and R package version 2.15.2 with a significant level of 0.05. Median follow-up for all patients was 7.1 years. The number of lymph nodes sampled was significantly related to lymph node status (p<0.001). Lymph node involvement portended worse overall survival after controlling for stage and histology. Patients treated with NAC had higher rates of 'unknown' lymph node status (p<0.001) and worse overall survival than their counterparts (p=0.002); within this group, patients with 'unknown' lymph node status had significantly worse survival than those with negative or positive lymph node. Our data support the available evidence that sampling of more than seven lymph nodes is necessary for adequate staging of Wilms tumour. This is especially critical in patients treated with NAC, who had worse overall survival, likely due to understaging and undertreatment. These findings should be confirmed prospectively to provide proper guidelines to physicians caring for patients with Wilms tumour.

The Effect of Transition Clinics on Knowledge of Diagnosis and Perception of Risk in Young Adult Survivors of Childhood Cancer.

BACKGROUND: Improved treatment for pediatric cancers has ensured an evergrowing population of patients surviving into adulthood. The current study evaluated the impact of previous engagement in survivor care on patient knowledge and awareness of health risks as young adults. PROCEDURE: Young adult survivors of childhood cancers (N=93, M age=23.63 y) were recruited during their annual survivor clinic visit. Participants completed self-reported measures of demographics, treatment knowledge, perception of future health risks, participation in previous survivor care, and neurocognitive functioning. RESULTS: In total, 82% of patients (N=76/93) reported previously participating in survivorship care. These patients were more likely to have knowledge of their radiation treatment (P=0.034) and more likely to recognize risk for future health effects from their treatment (P=0.019). Income between $10,000 and $24,999 (odds ratio=0.168; 95% confidence interval, 0.046-0.616; P=0.031) was associated with decreased patient knowledge regarding diagnosis. Male sex (odds ratio=0.324; 95% confidence interval, 0.135-0.777; P=0.012) was associated with less knowledge of future health risks. Patients with self-reported difficulties on the CCSS-NCQ were more likely to regard their cancer treatment as a future health risk. CONCLUSION: Participation in survivor care plays an important role in imparting information to young adult survivors of pediatric cancer regarding their disease history and risk for future health problems.

Factors Influencing Pulmonary Toxicity in Children Undergoing Allogeneic Hematopoietic Stem Cell Transplantation in the Setting of Total Body Irradiation-Based Myeloablative Conditioning.

PURPOSE: This study evaluated factors associated with increased risk of pulmonary toxicity (PT) from any cause in pediatric patients after myeloablative conditioning, using total body irradiation (TBI), followed by allogeneic hematopoietic stem cell transplantation (HSCT). METHODS AND MATERIALS: The records of 129 consecutive pediatric patients (range: 1-21 years of age) who underwent TBI-based myeloablative conditioning for hematologic malignancies at our institution between January 2003 and May 2014 were reviewed. Although total TBI doses ranged from 10.5 to 14 Gy, lung doses were limited to 10 Gy with partial transmission blocks. TBI dose rates ranged from 5.6 cGy/min to 20.9 cGy/min. PT was classified using clinical symptoms, radiographic evidence, and ventilatory defects on pulmonary function tests. Noninfectious (idiopathic) pneumonia syndrome (IPS) was characterized by patients exhibiting PT while demonstrating no signs of infection throughout the follow-up period. RESULTS: PT from any cause developed in 70.5% of patients and was significantly associated with increased transplantation-related mortality (TRM) (P=.03) and decreased overall survival (OS) (P=.02). IPS developed in 23.3% of patients but was not associated with increased TRM (P=.6) or decreased OS (P=.5). Acute graft-versus-host disease (GVHD) significantly affected PT (P=.001) but did not significantly influence the development of IPS (P=.4). Infection was a leading cause of PT (75.8%). TBI dose rate significantly affected development of overall PT (P=.02) and was the sole factor to significantly influence the incidence of IPS (P=.002). TBI total dose, dose per fraction, disease type, transplantation chemotherapy, age of patient, sex, and donor type did not significantly impact overall PT or IPS. CONCLUSIONS: A high incidence of PT was noted in this large series of homogeneously treated pediatric patients undergoing TBI for allogeneic HSCT. TBI dose rates affected overall PT and strongly influenced IPS. TBI dose rate is a contributing factor influencing pulmonary toxicity and rates less than 15 cGy/min should be considered to decrease the risk of IPS.

Stereotactic body radiation therapy versus no treatment for early stage non-small cell lung cancer in medically inoperable elderly patients: A National Cancer Data Base analysis.

BACKGROUND: Stereotactic body radiation therapy (SBRT) has demonstrated high rates of local control with low morbidity and has now emerged as the standard of care for medically inoperable, early stage non-small cell lung cancer (NSCLC). However, the impact of lung SBRT on survival in the elderly population is less clear given competing comorbid conditions. An analysis of the National Cancer Data Base (NCDB) was undertaken to determine whether definitive SBRT improves survival relative to observation alone patients ages 70 years and older. METHODS: The NCDB, a retrospective national database that captures approximately 70% of all patients treated for cancer, was queried for patients aged 70 years or older with early stage (T1-T3N0M0) NSCLC from 2003 to 2006. Overall survival was compared between patients who received stereotactic body radiotherapy alone and those who received no treatment. An extended Cox proportional hazards model was applied to estimate the treatment effect of SBRT. RESULTS: In total, 3147 patients met the selection criteria for this analysis. SBRT was delivered to 258 patients (8.2%), and 2889 patients (91.8%) received no treatment. There was no significant difference in the distribution of Charlson/Deyo comorbidity index scores between the 2 groups (P = .076). Multivariable analysis revealed improved overall survival with SBRT compared with observation for the entire cohort (hazard ratio, 0.64; P < .001). CONCLUSIONS: SBRT is associated with improved survival in elderly patients with early stage NSCLC who have concurrent comorbid conditions compared with observation alone. The current data support the use of SBRT for the treatment of elderly patients with early stage NSCLC who have limiting comorbid conditions.

Neoadjuvant modified FOLFIRINOX and chemoradiation therapy for locally advanced pancreatic cancer improves resectability.

BACKGROUND AND OBJECTIVES: Though necessary for improved outcomes, surgical resection is often limited in patients with locally advanced pancreatic cancers (LAPCs). We evaluated the efficacy of the approach adopted by our institution of using modified FOLFIRINOX chemotherapy followed by radiation with concurrent gemcitabine or capecitabine for patients with LAPCs, in an effort to enhance resectability while improving the toxicity profile compared with similar treatment regimens. METHODS: We included 29 consecutive patients with LAPC treated at our institution with the above approach in this review. We evaluated rates of resection, locol control, and survival outcomes in this cohort. RESULTS: The median follow up for this series of patients was 15.2 months. Approximately half the patients were unresectable at presentation. After neoadjuvant therapy, 41.3% of all patients were able to undergo resection of their tumors and 83% achieved an R0 resection. One-year local control for the entire cohort was 85%; one-year progression-free and overall were 49.2% and 65.5%, respectively. High rates of metastatic disease were seen regardless of resectability. There were minimal toxicities in this cohort. CONCLUSIONS: Neoadjuvant therapy with induction modified FOLFIRINOX and chemoradiation presents a well-tolerated, promising treatment approach for patients with LAPC. High rates of metastatic disease highlight the need to optimize systemic and targeted agents for pancreatic adenocarcinoma.

Influence of Pulmonary Nodules on Chest Computed Tomography and Risk of Recurrence in Stage IV Wilms Tumor.

PURPOSE: Chest computed tomography (CT) is currently accepted as the main modality for initial disease staging and response assessment in Wilms tumor (WT). However, there is great variability in the number and size of lung metastases at the time of diagnosis and after induction chemotherapy. There is a lack of clinical evidence as to how this variability in tumor burden affects choice of therapy and disease outcome. This study sought to evaluate a previously proposed lung metastases risk stratification system based on CT findings and clinical outcomes in stage IV WT patients. METHODS AND MATERIALS: Thirty-five pediatric patients with a diagnosis of stage IV WT with evaluable pre- and postdiagnosis CT scans between 1997 and 2012 were included in the analysis. Patients were divided into low-, intermediate-, and high-risk categories based on the size and number of pulmonary metastases before and after 6 weeks of chemotherapy. Association of the lung risk groups with lung recurrence-free survival and overall survival at each time point was analyzed with relevant covariates. RESULTS: Risk group distribution both at diagnosis and after induction chemotherapy was not influenced by tumor histology. Initial risk grouping suggested an association with disease-free survival at 5 years (P=.074); however, the most significant correlation was with postinduction chemotherapy disease status (P=.027). In patients with an intermediate or high burden of disease after 6 weeks of chemotherapy, despite receiving whole-lung and boost irradiation, survival outcomes were poorer. CONCLUSIONS: Pulmonary tumor burden in stage IV WT on chest CT can predict disease outcome. Patients with intermediate- or low-risk disease, especially after induction therapy, have a higher risk for recurrence. After prospective validation, this method may become a valuable tool in adaptation of therapy to improve outcome.