Current status of brachytherapy for prostate cancer

Comparison of the Medical Uses and Cellular Effects of High and Low Linear Energy Transfer Radiation

Exposure to ionizing radiation can occur during medical treatments, from naturally occurring sources in the environment, or as the result of a nuclear accident or thermonuclear war. The severity of cellular damage from ionizing radiation exposure is dependent upon a number of factors including the absorbed radiation dose of the exposure (energy absorbed per unit mass of the exposure), dose rate, area and volume of tissue exposed, type of radiation (e.g., X-rays, high-energy gamma rays, protons, or neutrons) and linear energy transfer. While the dose, the dose rate, and dose distribution in tissue are aspects of a radiation exposure that can be varied experimentally or in medical treatments, the LET and eV are inherent characteristics of the type of radiation. High-LET radiation deposits a higher concentration of energy in a shorter distance when traversing tissue compared with low-LET radiation. The different biological effects of high and low LET with similar energies have been documented in vivo in animal models and in cultured cells. High-LET results in intense macromolecular damage and more cell death. Findings indicate that while both low- and high-LET radiation activate non-homologous end-joining DNA repair activity, efficient repair of high-LET radiation requires the homologous recombination repair pathway. Low- and high-LET radiation activate p53 transcription factor activity in most cells, but high LET activates NF-kB transcription factor at lower radiation doses than low-LET radiation. Here we review the development, uses, and current understanding of the cellular effects of low- and high-LET radiation exposure.

Recent Advances in Brachytherapy Using Radioactive Nanoparticles: An Alternative to Seed-Based Brachytherapy

Interstitial brachytherapy (BT) is generally used for the treatment of well-confined solid tumors. One example of this is in the treatment of prostate tumors by permanent placement of radioactive seeds within the prostate gland, where low doses of radiation are delivered for several months. However, successful implementation of this technique is hampered due to several posttreatment adverse effects or symptoms and operational and logistical complications associated with it. Recently, with the advancements in nanotechnology, radioactive nanoparticles (radio-NPs) functionalized with tumor-specific biomolecules, injected intratumorally, have been reported as an alternative to seed-based BT. Successful treatment of solid tumors using radio-NPs has been reported in several preclinical studies, on both mice and canine models. In this article, we review the recent advancements in the synthesis and use of radio-NPs as a substitute to seed-based BT. Here, we discuss the limitations of current seed-based BT and advantages of radio-NPs for BT applications. Recent progress on the types of radio-NPs, their features, synthesis methods, and delivery techniques are discussed. The last part of the review focuses on the currently used dosimetry protocols and studies on the dosimetry of nanobrachytherapy applications using radio-NPs. The current challenges and future research directions on the role of radio-NPs in BT treatments are also discussed.

MANAGEMENT OF PROSTATE CANCER IN ACCRA, GHANA

INTRODUCTION

Africans living with prostate cancer in Africa face problems of early diagnosis and appropriate treatment.

AIM

To study the clinical incidence of prostate cancer, risk factors, TNM stage, their management and outcomes.

METHODS

A prospective study of Prostate Cancer cases managed at Korle Bu Teaching Hospital and hospitals in Accra, diagnosed by history, abnormal PSA/DRE, physical examination and histologically confirmed by biopsy from 2004 to 2013 was carried out. The cases were TNM staged and managed by approved protocol.

RESULTS

There were 669 cases with a mean age 70±0.045SE years, median Gleason Score of 7, organ confined Prostate Cancer(PC) in 415(62%), locally advanced in 167(25%) and metastatic Prostate Cancer in 87(13%) cases. The cases were followed for median of 10 months to ≥ 84 months. Organ confined cases were managed by: Radical Prostatectomy (RP) 92 (13.8%) with a mortality of 0.3%; brachytherapy 70 (10.5%) with a mortality of 0.1% and External Beam Radiotherapy (EBRT) 155 (23%) with a mortality 0.7%. In all, 98 men constituting (14.1%) cases with a mean age of 75+0.25SE years, life expectancy <10 years were treated by hormonal therapy with a mortality of 1.7%. Twenty cases who were for active surveillance (GS6), PSA <10ng/ml, life expectancy <10 years later all opted for EBRT. Locally advanced cases 25% all had neoadjuvant hormonal therapy then Brachytherapy in 3 (0.4%) mortality 0.15% and EBRT in 64 (9.5%), mortality 0.59%. Hormonal therapy was given in 100 (15%) locally advanced cases, mortality 5%. Metastatic prostate cancer cases (13%) were managed by hormonal therapy, mortality 6%.

CONCLUSION

Improved facilities and dedicated skilled teams led to a significant rise in proportion of organ confined Prostate Cancer from 15.3% to 62% curable by Radical Prostatectomy, brachytherapy or EBRT with longer disease free survival.

Low temperature plasma: a novel focal therapy for localized prostate cancer?

Despite considerable advances in recent years for the focal treatment of localized prostate cancer, high recurrence rates and detrimental side effects are still a cause for concern. In this review, we compare current focal therapies to a potentially novel approach for the treatment of early onset prostate cancer: low temperature plasma. The rapidly evolving plasma technology has the potential to deliver a wide range of promising medical applications via the delivery of plasma-induced reactive oxygen and nitrogen species. Studies assessing the effect of low temperature plasma on cell lines and xenografts have demonstrated DNA damage leading to apoptosis and reduction in cell viability. However, there have been no studies on prostate cancer, which is an obvious candidate for this novel therapy. We present here the potential of low temperature plasma as a focal therapy for prostate cancer.