The emergence of advanced brachytherapy techniques for common malignancies

The Predictive Value of 8-Hydroxy-Deoxyguanosine (8-OHdG) Serum Concentrations in Irradiated Non-Small Cell Lung Carcinoma (NSCLC) Patients

Ionizing radiation is strongly linked to direct or indirect DNA damage, as with the production of reactive oxygen species (ROS), which in turn produce DNA damage products, such as 8-hydroxy-2-deoxyguanosine (8-OHdG). In this study, we aimed to investigate the formation of 8-OHdG after irradiation in patients with non-small cell cancer (NSCLC) and its use as a biomarker. Sixteen patients with squamous and thirty-six patients with non-squamous pathology were included. An enzyme-linked-immunosorbent assay (ELISA) was performed before and after radiation. A dose-dependent relationship was confirmed: 8-OHdG plasma concentrations, increased in the total of NSCLC patients and specifically with a linear correlation in non-squamous pathology; in squamous histology, after an initial increase, a significant decrease followed after 20 Gy dose of irradiation. The pretreatment total irradiated tumor volume (cm3) was positively correlated with 8-OHdG levels in patients with squamous histology. When plotting the 8-OHdG plasma concentration at a 10 Gy irradiation dose to the baseline, the AUC was 0.873 (95% CI 0.614-0.984), p < 0.0001, with an associated criterion value of >1378 as a cutoff (sensitivity 72.7%, specificity 100%). When normalizing this ratio to BSA, the associated criterion cutoff value was >708 (sensitivity of 100%, specificity 80%). Lastly, 8-OHdG levels were closely related with the development of radiation-induced toxicities.

8-Hydroxy-2'-Deoxyguanosine and 8-Nitroguanine Production and Detection in Blood Serum of Breast Cancer Patients in Response to Postoperative Complementary External Ionizing Irradiation of Normal Tissues

It is widely known that ionizing irradiation is strongly linked to the production of reactive oxygen (ROS) and nitrative species (RNS) through which DNA damage products like 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-nitroguanine (8-NG) are generated, respectively. In the present study, we aimed to investigate the formation of 8-OHdG and 8-NG upon irradiation and to further explore whether alterations in their concentration levels are related to the administered radiation doses and exposure time. Our research work was conducted in blood serum samples collected from 33 breast cancer patients who received adjuvant radiotherapy. The detection of 8-OHdG and 8-NG was assessed by enzyme-linked immunosorbent assay. Our results suggest that both, 8-OHdG and 8-NG, were formed during the radiation regimen. Significant correlations with radiation dose were also demonstrated by the dose-response curves of 8-OHdG and 8-NG, fitted by logarithmic distribution and polynomial regression, respectively. More precisely, 8-OHdG and 8-NG concentrations (ng/mL) were considerably increased when patients received ionizing radiation up to 30 Gy whereas irradiation over 30 Gy did not induce any further increases. The current study supports a) the production of 8-OHdG and 8-NG during radiotherapy and b) significant correlations between either 8-OHdG or 8-NG levels and radiation doses, indicating a radiation-dose-dependent relationship.

The combined therapeutic effects of 131iodine-labeled multifunctional copper sulfide-loaded microspheres in treating breast cancer

Compared to conventional cancer treatment, combination therapy based on well-designed nanoscale platforms may offer an opportunity to eliminate tumors and reduce recurrence and metastasis. In this study, we prepared multifunctional microspheres loading 131I-labeled hollow copper sulfide nanoparticles and paclitaxel (131I-HCuSNPs-MS-PTX) for imaging and therapeutics of W256/B breast tumors in rats. 18F-fluordeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging detected that the expansion of the tumor volume was delayed (P<0.05) following intra-tumoral (i.t.) injection with 131I-HCuSNPs-MS-PTX plus near-infrared (NIR) irradiation. The immunohistochemical analysis further confirmed the anti-tumor effect. The single photon emission computed tomography (SPECT)/photoacoustic imaging mediated by 131I-HCuSNPs-MS-PTX demonstrated that microspheres were mainly distributed in the tumors with a relatively low distribution in other organs. Our results revealed that 131I-HCuSNPs-MS-PTX offered combined photothermal, chemo- and radio-therapies, eliminating tumors at a relatively low dose, as well as allowing SPECT/CT and photoacoustic imaging monitoring of distribution of the injected agents non-invasively. The copper sulfide-loaded microspheres, 131I-HCuSNPs-MS-PTX, can serve as a versatile theranostic agent in an orthotopic breast cancer model.

Cost-Utility Analysis of Single-Fraction Versus Multiple-Fraction Radiotherapy in Patients with Painful Bone Metastases: An Iranian Patient's Perspective Study

OBJECTIVES

To evaluate two of the various treatment strategies of bone metastasis- single-fraction radiotherapy and multiple-fraction radiotherapy.

METHODS

A multistage Markov decision model was applied to assess the incremental costs per quality-adjusted life-year (QALY) gained of single fraction against multiple fractions. The model had a monthly cycle length over a lifetime horizon with 1000 hypothetical cohort samples. The EuroQol five-dimensional questionnaire was used to estimate the health-related quality of life in patients. To cope with parameters of uncertainty, we conducted a probabilistic sensitivity analysis using a Monte-Carlo simulation technique. Both cost and utility variables were discounted by 3% in the base model. Strategies were assessed considering a willingness-to-pay threshold of US $6578 per QALY gained.

RESULTS

The expected mean cost and quality-adjusted life-years were, respectively, US $447.28 and 5.95 months for patients receiving single-fraction radiotherapy and US $1269.66 and 7.87 months for those receiving multiple-fraction radiotherapy. The incremental cost-utility ratio was US $428.38 per QALY. Considering the Iranian gross domestic product per capita (US $6578) as the recommended willingness to pay for 1 QALY gained, the multiple-fraction method was found to be a cost-effective strategy.

CONCLUSIONS

Policymakers should advocate the multiple-fraction method instead of the single-fraction method in the treatment of patients with painful bone metastases.

Chemophototherapy: An Emerging Treatment Option for Solid Tumors

Near infrared (NIR) light penetrates human tissues with limited depth, thereby providing a method to safely deliver non-ionizing radiation to well-defined target tissue volumes. Light-based therapies including photodynamic therapy (PDT) and laser-induced thermal therapy have been validated clinically for curative and palliative treatment of solid tumors. However, these monotherapies can suffer from incomplete tumor killing and have not displaced existing ablative modalities. The combination of phototherapy and chemotherapy (chemophototherapy, CPT), when carefully planned, has been shown to be an effective tumor treatment option preclinically and clinically. Chemotherapy can enhance the efficacy of PDT by targeting surviving cancer cells or by inhibiting regrowth of damaged tumor blood vessels. Alternatively, PDT-mediated vascular permeabilization has been shown to enhance the deposition of nanoparticulate drugs into tumors for enhanced accumulation and efficacy. Integrated nanoparticles have been reported that combine photosensitizers and drugs into a single agent. More recently, light-activated nanoparticles have been developed that release their payload in response to light irradiation to achieve improved drug bioavailability with superior efficacy. CPT can potently eradicate tumors with precise spatial control, and further clinical testing is warranted.

Theranostic Nanoseeds for Efficacious Internal Radiation Therapy of Unresectable Solid Tumors

Malignant tumors are considered “unresectable” if they are adhere to vital structures or the surgery would cause irreversible damages to the patients. Though a variety of cytotoxic drugs and radiation therapies are currently available in clinical practice to treat such tumor masses, these therapeutic modalities are always associated with substantial side effects. Here, we report an injectable nanoparticle-based internal radiation source that potentially offers more efficacious treatment of unresectable solid tumors without significant adverse side effects. Using a highly efficient incorporation procedure, palladium-103, a brachytherapy radioisotope in clinical practice, was coated to monodispersed hollow gold nanoparticles with a diameter about 120 nm, to form ¹⁰³Pd@Au nanoseeds. The therapeutic efficacy of ¹⁰³Pd@Au nanoseeds were assessed when intratumorally injected into a prostate cancer xenograft model. Five weeks after a single-dose treatment, a significant tumor burden reduction (>80%) was observed without noticeable side effects on the liver, spleen and other organs. Impressively, >95% nanoseeds were retained inside the tumors as monitored by Single Photon Emission Computed Tomography (SPECT) with the gamma emissions of ¹⁰³Pd. These findings show that this nanoseed-based brachytherapy has the potential to provide a theranostic solution to unresectable solid tumors.

Ionizing radiation-induced DNA injury and damage detection in patients with breast cancer

Breast cancer is the most common malignancy in women. Radiotherapy is frequently used in patients with breast cancer, but some patients may be more susceptible to ionizing radiation, and increased exposure to radiation sources may be associated to radiation adverse events. This susceptibility may be related to deficiencies in DNA repair mechanisms that are activated after cell-radiation, which causes DNA damage, particularly DNA double strand breaks. Some of these genetic susceptibilities in DNA-repair mechanisms are implicated in the etiology of hereditary breast/ovarian cancer (pathologic mutations in the BRCA 1 and 2 genes), but other less penetrant variants in genes involved in sporadic breast cancer have been described. These same genetic susceptibilities may be involved in negative radiotherapeutic outcomes. For these reasons, it is necessary to implement methods for detecting patients who are susceptible to radiotherapy-related adverse events. This review discusses mechanisms of DNA damage and repair, genes related to these functions, and the diagnosis methods designed and under research for detection of breast cancer patients with increased radiosensitivity.

Multidisciplinary care for patients with breast cancer

The care of patients with breast cancer has become increasingly complex with advancements in diagnostic modalities, surgical approaches, and adjuvant treatments. A multidisciplinary approach to breast cancer care is essential to the successful integration of available therapies. This article addresses the key components of multidisciplinary breast cancer care, with a special emphasis on new and emerging approaches over the past 10 years in the fields of diagnostics, surgery, radiation, medical oncology, and plastic surgery.

Accelerated partial breast irradiation in early-stage breast cancer

Whole-breast irradiation, as part of breast-conservation therapy (BCT), has well-established results, good cosmesis, and low toxicity. Results from the BCT trials suggest that the risk for ipsilateral breast cancer recurrence resides within close proximity to the original tumor site. This leads investigators to consider the role of an accelerated and more tumor bed-focused course of radiotherapy. Accelerated partial-breast irradiation (APBI) involves treating a limited volume of breast tissue, with dose of irradiation per fraction increased and the treatment time course decreased. Four currently available methods of APBI are interstitial brachytherapy, intracavitary brachytherapy, intraoperative radiotherapy, and three-dimensional conformal external-beam radiotherapy. Patient selection is critical. This review article presents some preliminary clinical observations and limitations that suggest a potential role for APBI as a more user-friendly mode for delivering radiotherapy after lumpectomy for early breast cancer.