Assessment of Micronuclei Frequency in the Peripheral Blood of Adult and Pediatric Patients Receiving Fractionated Total Body Irradiation.

The cytokinesis-block micronucleus (CBMN) assay is an established method for assessing chromosome damage in human peripheral blood lymphocytes resulting from exposure to genotoxic agents such as ionizing radiation. The objective of this study was to measure cytogenetic DNA damage and hematology parameters in vivo based on MN frequency in peripheral blood lymphocytes (PBLs) from adult and pediatric leukemia patients undergoing hematopoietic stem cell transplantation preceded by total body irradiation (TBI) as part of the conditioning regimen. CBMN assay cultures were prepared from fresh blood samples collected before and at 4 and 24 h after the start of TBI, corresponding to doses of 1.25 Gy and 3.75 Gy, respectively. For both age groups, there was a significant increase in MN yields with increasing dose (p < 0.05) and dose-dependent decrease in the nuclear division index (NDI; p < 0.0001). In the pre-radiotherapy samples, there was a significantly higher NDI measured in the pediatric cohort compared to the adult due to an increase in the percentage of tri- and quadri-nucleated cells scored. Complete blood counts with differential recorded before and after TBI at the 24-h time point showed a rapid increase in neutrophil (p = 0.0001) and decrease in lymphocyte (p = 0.0006) counts, resulting in a highly elevated neutrophil-to-lymphocyte ratio (NLR) of 14.45 ± 1.85 after 3.75 Gy TBI (pre-exposure = 4.62 ± 0.49), indicating a strong systemic inflammatory response. Correlation of the hematological cell subset counts with cytogenetic damage, indicated that only the lymphocyte subset survival fraction (after TBI compared with before TBI) showed a negative correlation with increasing MN frequency from 0 to 1.25 Gy (r = -0.931; p = 0.007). Further, the data presented here indicate that the combination of CBMN assay endpoints (MN frequency and NDI values) and hematology parameters could be used to assess cytogenetic damage and early hematopoietic injury in the peripheral blood of leukemia patients, 24 h after TBI exposure.

Assessment and Treatment Outcomes of Persistent Radiation-Induced Alopecia in Patients With Cancer.

Importance: Persistent radiation-induced alopecia (pRIA) and its management have not been systematically described. Objective: To characterize pRIA in patients with primary central nervous system (CNS) tumors or head and neck sarcoma. Design, Setting, and Participants: A retrospective cohort study of patients from January 1, 2011, to January 30, 2019, was conducted at 2 large tertiary care hospitals and comprehensive cancer centers. Seventy-one children and adults diagnosed with primary CNS tumors or head and neck sarcomas were evaluated for pRIA. Main Outcomes and Measures: The clinical and trichoscopic features, scalp radiation dose-response relationship, and response to topical minoxidil were assessed using standardized clinical photographs of the scalp, trichoscopic images, and radiotherapy treatment plans. Results: Of the 71 patients included (median [range] age, 27 [4-75] years; 51 female [72%]), 64 (90%) had a CNS tumor and 7 (10%) had head and neck sarcoma. Alopecia severity was grade 1 in 40 of 70 patients (56%), with localized (29 of 54 [54%]), diffuse (13 of 54 [24%]), or mixed (12 of 54 [22%]) patterns. The median (range) estimated scalp radiation dose was 39.6 (15.1-50.0) Gy; higher dose (odds ratio [OR], 1.15; 95% CI, 1.04-1.28) and proton irradiation (OR, 5.7; 95% CI, 1.05-30.8) were associated with greater alopecia severity (P < .001), and the dose at which 50% of patients were estimated to have severe (grade 2) alopecia was 36.1 Gy (95% CI, 33.7-39.6 Gy). Predominant trichoscopic features included white patches (16 of 28 [57%]); in 15 patients, hair-shaft caliber negatively correlated with scalp dose (correlation coefficient, -0.624; P = .01). The association between hair density and scalp radiation dose was not statistically significant (-0.381; P = .16). Twenty-eight of 34 patients (82%) responded to topical minoxidil, 5% (median follow-up, 61 [interquartile range, 21-105] weeks); 4 of 25 (16%) topical minoxidil recipients with clinical images improved in severity grade. Two patients responded to hair transplantation and 1 patient responded to plastic surgical reconstruction. Conclusions and Relevance: Persistent radiation-induced alopecia among patients with primary CNS tumors or head and neck sarcomas represents a dose-dependent phenomenon that has distinctive clinical and trichoscopic features. The findings of this study suggest that topical minoxidil and procedural interventions may have benefit in the treatment of pRIA.

Assessment of pulmonary outcomes, exercise capacity, and longitudinal changes in lung function in pediatric survivors of high-risk neuroblastoma.

BACKGROUND/OBJECTIVES: Survivors of high-risk neuroblastoma (NB) are exposed to multimodality therapies early in life and confront late therapy-related toxicities. This study assessed respiratory symptoms, exercise capacity, and longitudinal changes in pulmonary function tests (PFTs) among survivors. DESIGN/METHODS: Survivors of high-risk NB followed in the long-term follow-up clinic at Memorial Sloan Kettering Cancer Center were enrolled. Symptom and physical activity questionnaires were completed. Medical records were reviewed for treatments and comorbidities. Participants completed spirometry, plethysmography, diffusion capacity of the lung for carbon monoxide, 6-minute walk tests (6MWTs), and cardiopulmonary exercise testing. Questionnaires and PFTs were repeated at least one year after enrollment. RESULTS: Sixty-two survivors participated (median age at study: 10.92 years; median age at diagnosis: 2.75 years; median time since completion of therapy: 5.29 years). Thirty-two percent had chronic respiratory symptoms. Seventy-seven percent had PFT abnormalities, mostly mild to moderate severity. Thirty-three completed 6MWTs (median, 634.3 meters); eight completed cardiopulmonary exercise tests (mean VO2 max: 63% predicted); 23 completed a second PFT revealing declines over a median 2.97 years (mean percent predicted forced vital capacity: 79.9 to 70.0; mean forced expiratory volume in 1 second: 81.6 to 69.9). Risks for abnormalities included thoracic surgery, chest radiation therapy (RT), thoracic surgery plus chest RT, and hematopoietic stem cell transplant. CONCLUSIONS: In this cohort of survivors of high-risk NB, PFT abnormalities were common but mostly mild or moderate. Maximal exercise capacity may be affected by respiratory limitations and declines in lung function may occur over time. Continued pulmonary surveillance of this at-risk population is warranted.

Assessment of response to induction therapy and its influence on 5-year failure-free survival in group III rhabdomyosarcoma: the Intergroup Rhabdomyosarcoma Study-IV experience--a report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group.

PURPOSE: Initial response to induction chemotherapy predicts failure-free survival (FFS) in osteosarcoma and Ewing's sarcoma. For Intergroup Rhabdomyosarcoma Study (IRS) IV patients with group III rhabdomyosarcoma, we assessed whether reported response assessed by anatomic imaging at week 8 predicted FFS. PATIENTS AND METHODS: We studied 444 group III patients who received induction therapy, had response assessed at week 8 by anatomic imaging, and continued with protocol therapy. Induction chemotherapy was generally followed by radiation therapy (RT) starting after week 9. Response to induction therapy was determined at weeks 0 and 8. Local institutions coded response. RESULTS: Response rate for the entire cohort at week 8 was 77% (95% CI, 73% to 81%; complete response [CR], 21%; partial response [PR], 56%) but response had no influence on FFS (P = .57). Two hundred seventy-two patients received standard-timing RT at week 9 and thus only chemotherapy during induction. Response rate was 81% (95% CI, 76% to 86%; CR, 22%; PR, 59%). In these patients, response did not influence FFS except for those with alveolar histology. One hundred thirty-two other patients received chemotherapy and RT during induction (up-front RT). Response rate was 65% (95% CI, 57% to 73%; CR, 12%; PR, 53%), but response had no influence on FFS (P = .69). Forty patients received no RT at all (protocol violation) and response to induction therapy had no effect on FFS. CONCLUSION: In IRS-IV, response rate to induction therapy was 77% in group III patients, was independent of histology, and had no influence on FFS overall.