Modulation of Radiation Biomarkers in a Randomized Phase II Study of 131I-MIBG With or Without Radiation Sensitizers for Relapsed or Refractory Neuroblastoma.

PURPOSE: 131I-metaiodobenzylguanidine (131I-MIBG) has demonstrated efficacy as a single agent in neuroblastoma. Recent trials have focused on 131I-MIBG combination strategies, though little is known about the effect of putative radiosensitizers on biological markers of radiation exposure. METHODS AND MATERIALS: NANT2011-01 evaluated 131I-MIBG therapy alone (arm A) or in combination with vincristine/irinotecan (arm B) or vorinostat (arm C) for patients with relapsed or refractory neuroblastoma. Blood samples were collected before and after 131I-MIBG infusion to determine levels of radiation-associated biomarkers (transcript and protein). The association of biomarker with treatment arm, clinical response, and treatment toxicity was analyzed. RESULTS: The cohort included 99 patients who had at least 1 biomarker available for analysis. Significant modulation in most biomarkers between baseline, 72, and 96 hours following 131I-MIBG was observed. Patients in arm C had the lowest degree of modulation in FLT3 ligand protein. Lower baseline BCL2 transcript levels were associated with higher overall response. Patients with greater increases in FLT3 ligand at 96 hours after 131I-MIBG therapy were significantly more likely to have grade 4 thrombocytopenia. Peripheral blood gene expression of the BCL2 family of apoptotic markers (BCL2L1 and BAX transcripts) was significantly associated with grade 4 hematologic toxicity. RNA sequencing demonstrated little overlap in the top modulated peripheral blood transcripts between randomized arms. CONCLUSIONS: Peripheral blood biomarkers relevant to radiation exposure demonstrate significant modulation after 131I-MIBG and concomitant radiation sensitizers affect extent of modulation. Biomarkers related to hematopoietic damage and apoptosis were associated with hematologic toxicity.

Evaluation of Epigenetic and Radiomodifying Effects during Radiotherapy Treatments in Zebrafish.

Radiotherapy is still a long way from personalizing cancer treatment plans, and its effectiveness depends on the radiosensitivity of tumor cells. Indeed, therapies that are efficient and successful for some patients may be relatively ineffective for others. Based on this, radiobiological research is focusing on the ability of some reagents to make cancer cells more responsive to ionizing radiation, as well as to protect the surrounding healthy tissues from possible side effects. In this scenario, zebrafish emerged as an effective model system to test for radiation modifiers that can potentially be used for radiotherapeutic purposes in humans. The adoption of this experimental organism is fully justified and supported by the high similarity between fish and humans in both their genome sequences and the effects provoked in them by ionizing radiation. This review aims to provide the literature state of the art of zebrafish in vivo model for radiobiological studies, particularly focusing on the epigenetic and radiomodifying effects produced during fish embryos' and larvae's exposure to radiotherapy treatments.

Concurrent Nab-paclitaxel and Radiotherapy: Novel Radiosensitization for Borderline Resectable or Unresectable Pancreatic Cancer.

PURPOSE: This study evaluates the toxicity and tumor response with concurrent nab-paclitaxel chemoradiotherapy (CRT) compared with standard (5-fluorouracil or gemcitabine) CRT. MATERIALS AND METHODS: Fifty patients with borderline resectable or unresectable pancreatic adenocarcinoma from 2014 to 2017 were divided into 2 groups: concurrent nab-paclitaxel (100 to 125 mg/m2 weekly) CRT (median: 2.1 Gy fraction size and 52.5 Gy total) or standard CRT (median: 1.8 Gy fraction size, 54.5 Gy total). The primary endpoint was toxicity, and secondary endpoints were local failure and conversion to resectability. Comparisons were made using rank-sum or Fisher exact test and multivariable competing risk regression for the cumulative incidence of local failure. RESULTS: There were 28 patients in the nab-paclitaxel CRT group and 22 in the standard CRT group; 88% had the unresectable disease. The median follow-up was 18 months. The median duration of chemotherapy before concurrent CRT was 1.9 and 2.3 months in the nab-paclitaxel and standard CRT groups (P=0.337), and radiotherapy dose was 52.5 Gy (range, 52.5 to 59.4 Gy) and 54.5 Gy (range, 45.0 to 59.4 Gy), respectively. There were no statistically significant grade ≥2 toxicities. The nab-paclitaxel CRT group experienced a nonstatistically significant lower incidence of local failure (hazard ratio=0.91, 95% confidence interval: 0.27-3.03, P=0.536). More patients in the nab-paclitaxel CRT group proceeded to surgery (9/28 compared with 3/22 in the standard CRT, P=0.186); of which 6 (25%) in the nab-paclitaxel CRT and 2 (10%) in the standard CRT groups were initially unresectable. CONCLUSIONS: Nab-paclitaxel CRT had similar toxicity compared with standard CRT in the treatment of borderline resectable or unresectable pancreatic cancer. Its use was associated with an arithmetically lower cumulative incidence of local failure and an arithmetically higher conversion to resectability, both of which were not statistically significant.

Why Concurrent CDDP and Radiotherapy Has Synergistic Antitumor Effects: A Review of In Vitro Experimental and Clinical-Based Studies.

Chemo-radiotherapy, which combines chemotherapy with radiotherapy, has been clinically practiced since the 1970s, and various anticancer drugs have been shown to have a synergistic effect when used in combination with radiotherapy. In particular, cisplatin (CDDP), which is often the cornerstone of multi-drug combination cancer therapies, is highly versatile and frequently used in combination with radiotherapy for the treatment of many cancers. Therefore, the mechanisms underlying the synergistic effect of CDDP and radiotherapy have been widely investigated, although no definitive conclusions have been reached. We present a review of the combined use of CDDP and radiotherapy, including the latest findings, and propose a mechanism that could explain their synergistic effects. Our hypothesis involves the concepts of overlap and complementation. "Overlap" refers to the overlapping reactions of CDDP and radiation-induced excessive oxidative loading, which lead to accumulating damage to cell components, mostly within the cytoplasm. "Complementation" refers to the complementary functions of CDDP and radiation that lead to DNA damage, primarily in the nucleus. In fact, the two concepts are inseparable, but conceptualizing them separately will help us understand the mechanism underlying the synergism between radiation therapy and other anticancer drugs, and help us to design future radiosensitizers.

Hearing Loss Risk in Pediatric Patients Treated with Cranial Irradiation and Cisplatin-Based Chemotherapy.

PURPOSE: Cranial radiation therapy (RT) and cisplatin-based chemotherapy are essential to treating many pediatric cancers but cause significant ototoxicity. The objective of this study is to determine the relationship between the RT dose and the risk of subsequent hearing loss in pediatric patients treated with cisplatin. METHODS AND MATERIALS: This retrospective study of cisplatin-treated pediatric patients examined ototoxicity from cranial RT. Ototoxicity was graded for each ear according to the International Society of Pediatric Oncology (SIOP) consensus ototoxicity scale. The RT dose to the cochlea was calculated using the mean, median, maximum, and minimum dose received to determine the most predictive parameter for hearing loss. Multivariable logistic regression models then examined risk factors for hearing loss. RESULTS: In 96 children (161 ears) treated with RT + cisplatin, the minimum cochlear RT dose was most predictive of hearing loss. A higher cochlear RT dose was associated with increased hearing loss (odds ratio per 10 Gy dose increase = 1.64; P = .043), with an added risk in those receiving an autologous bone marrow transplantation (hazard ratio = 10.47; P < .001). CONCLUSIONS: This research supports further testing of the minimum cochlear RT dose as a more predictive dose parameter for risk of ototoxicity. The cochlear RT dose was additive to the risk of hearing loss from underlying cisplatin-based chemotherapy. Exposure to autologous bone marrow transplantation was the strongest predictor of developing hearing loss, placing these children at particularly high risk for hearing loss across all cochlear doses. Future prospective studies are crucial to further inform RT dose thresholds and minimize the risk of hearing loss in childhood cancer survivors.

Decrease in treatment intensity predicts worse outcome in patients with locally advanced head and neck squamous cell carcinoma undergoing radiochemotherapy.

PURPOSE: Radiochemotherapy (RCT) is an effective standard therapy for locally advanced head and neck squamous cell carcinoma (LA-HNSCC). Nonetheless, toxicity is common, with patients often requiring dose modifications. METHODS: To investigate associations of RCT toxicities according to CTCAE version 5.0 and subsequent therapy modifications with short- and long-term treatment outcomes, we studied all 193 patients with HNSCC who received RCT (70 Gy + platinum agent) at an academic center between 03/2010 and 04/2018. RESULTS: During RCT, 77 (41%, 95% CI 34-49) patients developed at least one ≥ grade 3 toxicity, including seven grade 4 and 3 fatal grade 5 toxicities. The most frequent any-grade toxicities were xerostomia (n = 187), stomatitis (n = 181), dermatitis (n = 174), and leucopenia (n = 98). Eleven patients (6%) had their radiotherapy schedule modified (mean radiotherapy dose reduction = 12 Gy), and 120 patients (64%) had chemotherapy modifications (permanent discontinuation: n = 67, pause: n = 34, dose reduction: n = 7, change to other chemotherapy: n = 10). Objective response rates to RCT were 55% and 88% in patients with and without radiotherapy modifications (p = 0.003), and 84% and 88% in patients with and without chemotherapy modifications (p = 0.468), respectively. Five-year progression-free survival estimates were 20% and 50% in patients with and without radiotherapy modifications (p = < 0.001), and 53% and 40% in patients with and without chemotherapy modifications (p = 0.88), respectively. CONCLUSIONS: Reductions of radiotherapy dose were associated with impaired long-term outcomes, whereas reductions in chemotherapy intensity were not. This suggests that toxicities during RCT should be primarily managed by modifying chemotherapy rather than radiotherapy.

Localized Delivery of Cisplatin to Cervical Cancer Improves Its Therapeutic Efficacy and Minimizes Its Side Effect Profile.

PURPOSE: Cervical cancer represents the fourth most frequent malignancy in the world among women, and mortality has remained stable for the past 4 decades. Intravenous cisplatin with concurrent radiation therapy is the standard-of-care for patients with local and regional cervical cancer. However, cisplatin induces serious dose-limiting systemic toxicities and recurrence frequently occurs. In this study, we aimed to develop an intracervical drug delivery system that allows cisplatin release directly into the tumor and minimize systemic side effects. METHODS AND MATERIALS: Twenty patient biopsies and 5 cell lines treated with cisplatin were analyzed for platinum content using inductively coupled plasma mass spectrometry. Polymeric implants loaded with cisplatin were developed and evaluated for degradation and drug release. The effect of local or systemic cisplatin delivery on drug biodistribution as well as tumor burden were evaluated in vivo, in combination with radiation therapy. RESULTS: Platinum levels in patient biopsies were 6-fold lower than the levels needed for efficacy and radiosensitization in vitro. Cisplatin local delivery implant remarkably improved drug specificity to the tumor and significantly decreased accumulation in the blood, kidney, and other distant normal organs, compared with traditional systemic delivery. The localized treatment further resulted in complete inhibition of tumor growth. CONCLUSIONS: The current standard-of-care systemic administration of cisplatin provides a subtherapeutic dose. We developed a polymeric drug delivery system that delivered high doses of cisplatin directly into the cervical tumor, while lowering drug accumulation and consequent side effects in normal tissues. Moving forward, these data will be used as the basis of a future first-in-human clinical trial to test the efficacy of localized cisplatin as adjuvant or neoadjuvant chemotherapy in local and regional cervical cancer.

Erlotinib Versus Etoposide/Cisplatin With Radiation Therapy in Unresectable Stage III Epidermal Growth Factor Receptor Mutation-Positive Non-Small Cell Lung Cancer: A Multicenter, Randomized, Open-Label, Phase 2 Trial.

PURPOSE: This study aimed to compare erlotinib (E) and etoposide/cisplatin (EP) with concurrent radiation therapy (RT) for patients with stage IIIA/B unresectable advanced non-small cell lung cancer with activating epidermal growth factor receptor mutation (EGFRm+). METHODS AND PATIENTS: This was a multicenter, randomized, open-label, phase 2 trial conducted across 19 institutions in China (December 2012 to January 2016). Enrolled patients were randomized (1:1) to E + RT (oral erlotinib 150 mg/d for 2 years or until disease progression or intolerable toxicity and RT 200 cGy/d, 5 d/wk for 6 weeks from the first day of erlotinib) or EP + RT (etoposide 50 mg/m2 intravenously on days 1-5 and 29-33; cisplatin 50 mg/m2 intravenously on days 1, 8, 29 and 36; and RT as for E + RT). The primary endpoint was progression-free survival (PFS). Secondary endpoints included objective response rate and safety. RESULTS: Two hundred fifty-two patients were screened, and 20 patients with EGFRm+ in each group received the allocated E + RT or EP + RT treatment. Patient characteristics were well balanced between groups. Compared with EP + RT, median PFS with E + RT was significantly longer (24.5 vs 9.0 months [hazard ratio, 0.104; 95% confidence interval, 0.028-0.389; P < .001]). Objective response rate in the E + RT and EP + RT groups was 70% and 61.9%, respectively (P = .744). The incidence of adverse events (any grade) was similar between E + RT and EP + RT groups (88.9% and 84.2%). CONCLUSIONS: The primary endpoint of PFS was met, and the data showed that E + RT might provide PFS improvement compared with EP + RT, with similar tolerability. However, definitive statements regarding the efficacy of concurrent E + RT in patients with unresectable stage III non-small cell lung cancer with activating EGFRm+ cannot be made, and slow patient accrual will likely make it infeasible to conduct a phase 3 study.

Clinical Outcomes and Safety of Patients Treated with NAb-Paclitaxel Plus Gemcitabine in Metastatic Pancreatic Cancer: The NAPA Study.

BACKGROUND: The phase III MPACT trial demonstrated the superiority of gemcitabine (Gem) combined with Nab-paclitaxel (Nab-P) versus gemcitabine alone in previously untreated patients with metastatic pancreatic ductal adenocarcinoma (PDAC). The purpose of this study was to evaluate the effect of Gem/Nab-P in routine clinical practice. METHODS: From January 2015 to December 2018, patients with metastatic PDAC receiving firstline treatment with a combination of gemcitabine and Nab-paclitaxel were included in a multicentre retrospective observational study. Exploratory analyses of efficacy, and prognostic and predictive markers, were performed. RESULTS: The cohort comprised 115 patients (median age 65 [range 50-84] years) with good performance status (ECOG PS 0-1). The median overall survival (OS) was 11 months (95% CI; 9-13) and the median progression-free survival (PFS) was 6 months (95% CI 5-7). Partial response and stable disease were achieved in 44 and 30 patients, respectively, yielding an overall disease control rate (DCR) of 64.3%. Grade 3-4 hematological toxicity frequency was 22.61% for neutropenia, 5.22% for anemia, and 3.48% for thrombocytopenia. Grade 3 asthenia was recorded in 2.61% of patients. No grade 4 non-hematological events were reported. Dose reduction was necessary in 51.3% of the patients. CONCLUSION: Our results confirm the efficacy and safety of a first-line regimen comprising gemcitabine and Nab-paclitaxel in metastatic PDAC in a real-life population.

AsiDNA Is a Radiosensitizer with no Added Toxicity in Medulloblastoma Pediatric Models.

PURPOSE: Medulloblastoma is an important cause of mortality and morbidity in pediatric oncology. Here, we investigated whether the DNA repair inhibitor, AsiDNA, could help address a significant unmet clinical need in medulloblastoma care, by improving radiotherapy efficacy without increasing radiation-associated toxicity. EXPERIMENTAL DESIGN: To evaluate the brain permeability of AsiDNA upon systemic delivery, we intraperitoneally injected a fluorescence form of AsiDNA in models harboring brain tumors and in models still in development. Studies evaluated toxicity associated with combination of AsiDNA with radiation in the treatment of young developing animals at subacute levels, related to growth and development, and at chronic levels, related to brain organization and cognitive skills. Efficacy of the combination of AsiDNA with radiation was tested in two different preclinical xenografted models of high-risk medulloblastoma and in a panel of medulloblastoma cell lines from different molecular subgroups and TP53 status. Role of TP53 on the AsiDNA-mediated radiosensitization was analyzed by RNA-sequencing, DNA repair recruitment, and cell death assays. RESULTS: Capable of penetrating young brain tissues, AsiDNA showed no added toxicity to radiation. Combination of AsiDNA with radiotherapy improved the survival of animal models more efficiently than increasing radiation doses. Medulloblastoma radiosensitization by AsiDNA was not restricted to a specific molecular group or status of TP53. Molecular mechanisms of AsiDNA, previously observed in adult malignancies, were conserved in pediatric models and resembled dose increase when combined with irradiation. CONCLUSIONS: Our results suggest that AsiDNA is an attractive candidate to improve radiotherapy in medulloblastoma, with no indication of additional toxicity in developing brain tissues.

Low-Dose Hsp90 Inhibitor Selectively Radiosensitizes HNSCC and Pancreatic Xenografts.

PURPOSE: Treatment approaches using Hsp90 inhibitors at their maximum tolerated doses (MTDs) have not produced selective tumor toxicity. Inhibition of Hsp90 activity causes degradation of client proteins including those involved in recognizing and repairing DNA lesions. We hypothesized that if DNA repair proteins were degraded by concentrations of an Hsp90 inhibitor below those required to cause nonspecific cytotoxicity, significant tumor-selective radiosensitization might be achieved. EXPERIMENTAL DESIGN: Tandem mass tagged-mass spectrometry was performed to determine the effect of a subcytotoxic concentration of the Hsp90 inhibitor, AT13387 (onalespib), on global protein abundance. The effect of AT13387 on in vitro radiosensitization was assessed using a clonogenic assay. Pharmacokinetics profiling was performed in mice bearing xenografts. Finally, the effect of low-dose AT13387 on the radiosensitization of three tumor models was assessed. RESULTS: A subcytotoxic concentration of AT13387 reduced levels of DNA repair proteins, without affecting the majority of Hsp90 clients. The pharmacokinetics study using one-third of the MTD showed 40-fold higher levels of AT13387 in tumors compared with plasma. This low dose enhanced Hsp70 expression in peripheral blood mononuclear cells (PBMCs), which is a biomarker of Hsp90 inhibition. Low dose monotherapy was ineffective, but when combined with radiotherapy, produced significant tumor growth inhibition. CONCLUSIONS: This study shows that a significant therapeutic ratio can be achieved by a low dose of Hsp90 inhibitor in combination with radiotherapy. Hsp90 inhibition, even at a low dose, can be monitored by measuring Hsp70 expression in PBMCs in human studies.

Chemotherapy in the definitive management of oral cancers: Where do we stand today?

The treatment of locally advanced oral cavity cancer is often multimodal, involving surgical resection, radiotherapy (RT), and chemotherapy. Systemic therapy is the mainstay of treatment for recurrent/metastatic disease. While the concurrent use of cisplatin with post-operative RT is well established in patients with high risk features of extranodal extension and/or positive surgical margins following resection, the role of chemotherapy in other curative settings is not clear. Studies reporting success of induction chemotherapy or definitive chemoradiotherapy in absence of primary resection include all anatomic sites of head and neck cancer, and oral cavity cancer subset is rarely reported as a separate analysis, thus limiting the interpretation of results. This article will focus on the use of systemic therapy for locoregionally advanced oral cavity cancer.

The Histone Deacetylase Inhibitor Romidepsin Spares Normal Tissues While Acting as an Effective Radiosensitizer in Bladder Tumors in Vivo.

PURPOSE: Muscle-invasive bladder cancer has a 40% to 60% 5-year survival rate with radical treatment by surgical removal of the bladder or radiation therapy-based bladder preservation techniques, including concurrent chemoradiation. Elderly patients cannot tolerate current chemoradiation therapy regimens and often receive only radiation therapy, which is less effective. We urgently need effective chemotherapy agents for use with radiation therapy combinations that are nontoxic to normal tissues and tolerated by elderly patients. METHODS AND MATERIALS: We have identified histone deacetylase (HDAC) inhibitors as promising agents to study. Pan-HDAC inhibition, using panobinostat, is a good strategy for radiosensitization, but more selective agents may be more useful radiosensitizers in a clinical setting, resulting in fewer systemic side effects. Herein, we study the HDAC class I-selective agent romidepsin, which we predict to have fewer off-target effects than panobinostat while maintaining an effective level of tumor radiosensitization. RESULTS: In vitro effects of romidepsin were assessed by clonogenic assay and showed that romidepsin was effective in the nanomolar range in different bladder cancer cells and radiosensitized these cells. The radiosensitizing effect of romidepsin was confirmed in vivo using superficial xenografts. The drug/irradiation combination treatment resulted in significant tumor growth delay but did not increase the severity of acute (3.75 days) intestinal normal tissue toxicity or late toxicity at 29 weeks. Moreover, we showed that romidepsin treatment impaired both homologous recombination and nonhomologous end joining DNA repair pathways, suggesting that the disruption of DNA repair pathways caused by romidepsin is a key mechanism for its radiosensitizing effect in bladder cancer cells. CONCLUSIONS: This study demonstrates that romidepsin is an effective radiosensitizer in vitro and in vivo and does not increase the acute and late toxicity after ionizing radiation. Romidepsin is already in clinical use for the cutaneous T-cell lymphoma, but a phase 1 clinical trial of romidepsin as a radiosensitizer could be considered in muscle-invasive bladder cancer.

High-dose intensity-modulated chemoradiotherapy in vulvar squamous cell carcinoma: Outcome and toxicity.

INTRODUCTION: To evaluate clinical outcomes, pattern of failure, and toxicity after high-dose intensity-modulated radiation therapy (IMRT) for advanced vulvar cancer. METHODS: In this IRB approved retrospective study, the charts of women with histologically confirmed, non-metastatic vulvar cancer consecutively treated at our institution from 2012 to 2018 were reviewed to identify patients that received high-dose IMRT with curative intent. The treatment compliance, toxicities, and patterns of failure were investigated. Actuarial local, regional and distant recurrence and survival were estimated using Kaplan-Meier method and compared using log rank test. RESULTS: Twenty-six patients were identified, 23 were unresectable, and 3 refused surgery. Fifteen patients (58%) had inguinal node metastases; 10(38%) had pelvic node metastases. Elective surgical staging of groins was performed in 9-patients. Median tumor dose was 65.4Gy. Concurrent platinum-based chemotherapy was administered in 22(84.6%) patients. Complete response (CR) was achieved in 21/26 (80.7%) patients. Five patients had persistent disease following treatment and one sustained recurrence 5-months following radiotherapy. All persistent or recurrent disease occurred inside the irradiated volume. Median follow-up was 19 months (3-52 months). Actuarial 1-year local, regional and distant controls were 72.4%, 85.4%, and 86%, respectively. One and 2-year overall survivals were 91% and 62%, respectively. Complete response at 3-months was a strong predictor for overall survival (1-yr OS 73% vs 27%, HR 7.1 (95% CI 1.2-44); p = 0.01). Lymph node metastases adversely affected overall survival (2-yr OS 49% vs. 83%, p = 0.09). Grade 3-4 late urinary and soft-tissue toxicity was seen in 5 patients. Tumor doses >66 Gy (p = 0.03) and prior pelvic radiotherapy (p = 0.002) predicted grade 3-4 toxicity. CONCLUSION: High-dose IMRT for vulvar cancer achieves high rates of local control with acceptable dose dependent long-term toxicity.

[Use of nanoparticles as radiosensitizing agents in radiotherapy: State of play]. / Utilisation de nanoparticules comme agent radiosensibilisant en radiothérapie : où en est-on ?

Nanomedicine has undergone significant development since the 2000s and it is only very recently that two metallic nanoparticles have emerged in clinical trials. The mechanism of these radiosensitizing agents is based on the presence of atoms with a high atomic number (Z) allowing a higher dose deposition into the tumor during irradiation. The first nanoparticle used in humans is NBTXR3, composed of hafnium (Z=79), with intratumor injection for the treatment of sarcoma. Another gadolinium-based nanoparticle (Z=64), AGuIX, has been used for intravenous injection in the treatment of brain metastases. The preliminary results are promising in terms of feasibility, safety and efficacy, as evidenced by the significant number of ongoing clinical trials. The upcoming challenges for the development of nanoparticles will be the targeting of cancer cells, their biodistribution into the body, their eventual toxicity and their industrial production. In the coming years, modalities of administration and optimal combinations with radiotherapy should be defined in connection with fundamental research.

Radiosensitization of orthotopic GIC-driven glioblastoma by doxycycline causes skin damage.

Doxycycline (DXC) is a tetracycline antibiotic which has been proposed as a breast cancer radiosensitizer by specifically reducing the expression of the DNA repair enzyme DNA PK in breast cancer initiating cells. Since DXC presents favorable pharmacokinetics properties including the capacity to cross the blood-brain barrier, it has been hypothesized that it could radiosensitize brain tumors as well. We have investigated the radiosensitizing capacity of DXC towards human glioma initiating cells (GIC)-driven orthotopic glioblastomas (GB) in NOD/SCID mice that faithfully mimic the growth properties of the clinical tumors of origin. DXC at 10 mg/Kg body weight was subcutaneously delivered daily, 5 days/week for 4 weeks. At the same time, radiotherapeutic fractions of 0.25 Gy to the head were delivered every 3-4 days (twice/week) for 15 weeks. No survival advantage was observed in DXC-treated mice as compared to vehicle-treated mice by this radiosensitizing protocol. On the contrary, skin damage with hair loss and deep ulcers were observed after 4 weeks in DXC-treated mice leading to discontinuation of drug treatment. These results do not support the use of DXC as a radiosensitizer for brain tumors and indicate skin damage as an important side effect of DXC.

Radio-sensitization efficacy of gold nanoparticles in inhalational nanomedicine and the adverse effect of nano-detachment due to coating inactivation.

Gold nanoparticles (GNPs) are an emerging area of interest in radiation therapy due to their unique radio-sensitizing properties. In the literature, the enhancing capability of GNPs is usually quantified using the metric dose enhancement ratio (DER). Traditionally, the focus of the vast majority of studies has always been on intravenous administration of GNPs. However, recent work showed the potential of using GNP inhalation, rather than intravenous injection, to enhance the dose to the lung. Yet, some of these studies are employing simplistic analytical methods to calculate DER and, thus far, there are no detailed computations of the enhancement profiles therein. Moreover, the coating on the GNP surface can be adversely affected by the large gradient of the radiation dose in the immediate vicinity of GNPs, leading to the rupture of ligands and detachment of GNPs from the surface of the membrane, and hence the loss of its efficacy. In this study, a next-generation deterministic code was used to resolve the DER profile at the interface between the septum, air, and surface of GNPs when they are attached and detached. The results show that the large values of DER in conjunction with the developed hot spots are very effective in lung treatment; on the other hand, coating rupture can lead to significant reduction in DER that may reach 64%. Thus, GNPs can be beneficial in inhalational medicine to treat lung cancer, provided that more comprehensive studies on the characteristics of the coating are addressed to maximize the radio-therapeutic benefit of GNPs.

A prospective study to compare the measured glomerular filtration rate compared to estimated glomerular filtration rate in patients undergoing definitive chemoradiation, with platinum agents for various malignancies.

CONTEXT: Renal function assessment is of paramount importance before using the platinum agents especially cisplatin. Glomerular filtration rate (GFR) estimation by diethyl-triamine-penta-acetic acid (DTPA) scan (measured GFR [mGFR]) is considered gold standard. AIMS: The aim of this study is to know if we can replace the mGFR with the GFR estimation with Cockcroft-Gault formula (eGFR) in patients undergoing chemoradiation. SETTINGS AND DESIGN: This is a prospective, descriptive study. SUBJECTS AND METHODS: Patients who are planned for definitive chemoradiation will be eligible for the study. Renal function will be measured DTPA scan and Cockcroft-Gault (CG) formula. Subgroup analysis based on the weight, age, and sex will be done. STATISTICAL ANALYSIS USED: Demographic and renal function parameters were analyzed using summary measures. To test the significance of the difference between mGFR and cGFR, a paired t-test will be used; to look for an association between various estimates of renal function, the Pearson's correlation coefficient will be calculated using a two-tailed test. RESULTS: Median mGFR of patients was 82.7 (range: 65-125 ml/min, standard deviation [SD] =14.0 ml/min) while the median eGFR as per the CG formula was 83.9 ml/min (range: 37-137 ml/min, SD = 24.4 ml/min). The median mGFR was only 1.2 ml/min lesser when measures by the CG formula with no significance difference between them (P = 0.66, 95% confidence interval: -4.5-6.3). CONCLUSIONS: We concluded that in resource-limited setting eGFR using CG formula can replace mGFR, especially in patients with age <60 years. Although weight did not showed a significant difference by two methods, a study with large sample is needed to confirm the result.