Dose escalation of external beam radiotherapy for high-risk prostate cancerdImpact of multiple high-risk factor

Objective:To retrospectively investigate the treatment outcomes of external beam radiotherapy with androgen deprivation therapy(ADT)in high-risk prostate cancer in three radiotherapy dose groups.Methods:Between 1998 and 2013,patients with high-risk prostate cancer underwent threedimensional conformal radiotherapy or intensity-modulated radiotherapy of 66 Gy,72 Gy,or 78 Gy with ADT.Prostate-specific antigen(PSA)relapse was defined using the Phoenix definition.PSA relapse-free survival(PRFS)was evaluated in each radiotherapy dose group.Moreover,high-risk patients were divided into H-1(patients with multiple high-risk factors)and H-2(patients with a single high-risk factor)as risk subgroups.Results:Two hundred and eighty-nine patients with a median follow-up period of 77.3 months were analyzed in this study.The median duration of ADT was 10.1 months.Age,Gleason score,T stage,and radiotherapy dose influenced PRFS with statistical significance both in univariate and multivariate analyses.The 4-year PRFS rates in Group-66 Gy,Group-72 Gy and Group-78 Gy were 72.7%,81.6%and 90.3%,respectively.PRFS rates in the H-1 subgroup differed with statistical significance with an increasing radiotherapy dose having a more favorable PRFS,while PRFS rates in H-2 subgroup did not differ with increase in radiotherapy dose.Conclusion:Dose escalation for high-risk prostate cancer in combination with ADT improved PRFS.PRFS for patients in the H-1 subgroup was poor,but dose escalation in those patients was beneficial,while dose escalation in the H-2 subgroup was not proven to be effective for improving PRFS.

Linear Accelerator Based External Beam Radiotherapy in Glomus Jugulare Tumour: A Retrospective Review from a Tertiary Cancer Hospital in Kenya

Objective: Tumours originating from jugular bulb, carotid bifurcation, Vagus nerve are collectively called Paragangliomas. They are slow growing, essentially benign tumours, but can be detrimental if untreated. There is limited evidence on the effectiveness of fractionated radiotherapy in the management ofs Glomus jugulare tumours. The aim of this study is to determine the efficacy of Linear accelerator based fractionated external beam radiotherapy on unilateral inoperable Glomus jugulare paragangliomas. Method: This is a retrospective analysis of all the 12 cases of inoperable, unilateral Glomus jugulare tumours treated during the period 2011-2016 at a tertiary cancer centre in Kenya. Minimum follow up duration was 3 years. Patient characteristics, disease staging, immediate complications and therapeutic efficacy were analysed from the case files. Results: The 12 patients diagnosed with inoperable Glomus jugulare tumours reported in this period were treated with external beam radiotherapy to a tumour dose of 54 Gy in 30 fractions over a period of 6 weeks using IMRT technique in 6 MV Linear accelerator. 2/3rd of the patients were females in 5th and 6th decade of life. Onset of first symptom to initiation of treatment was found to be 1.7 years. Headache, earache, and tinnitus were the main complaints. No major side effects were recorded during therapy. Mean length of the tumour in its maximum dimension at the time of diagnosis was 4.5 cm. At the end of one-year post therapy, a mean reduction of 6.5 mm in the tumour length was observed, (Range: 0 - 15 mm). Tumour size remained static for a year and thereafter a slow growth pattern of 1mm per year was observed. Conclusion: Fractionated external beam radiotherapy is an effective and non-invasive treatment for advanced, inoperable Glomus jugulare paragangliomas. Clinical stability through tumour control was observed. Though newer radiation techniques like Cyberknife, Proton therapy offer better tumour control, conventional external beam radiotherapy is an effective tool in disease containment in resource limited countries.

Radiation Oncology and Medical Devices( Part 1)

Modern radiation treatments have become fairly complex and involve in utilizing a variety of medical devices to achieve the goal of providing conformal radiation dose coverage to the tumor target(s)while maximizing the sparing of normal organ structures.Recently,different forms of linear accelerators/radioactive source based machines have been invented and developed with the aim of providing improved treatments and more treatment options.Besides linear accelerators(Linac)that have been undergoing constant improvement and advancement and can deliver fairly complicated dose distribution patterns,imaging systems,computer information and calculation systems have been more and more integrated into radiotherapy processes.To bring radiotherapy to a potentially higher level,many institutions have either acquired or started to consider particle therapy,especially proton therapy.The complexity of modern radiotherapy demands in-depth understanding of radiation physics and machine engineering as well as computer information systems.This paper is intended to provide an introductory description of radiation oncology and related procedures,and to provide an overview of the current status of medical devices in radiotherapy in the United States of America.This paper covers the radiation delivery systems,imaging systems,treatment planning systems,record and verify systems,and QA systems.

Radiation Oncology and Medical Devices(Part 2)

Radiation oncology is one of the three major treatment modalities to manage cancer patient cares,and is a discipline mainly driven by technology and medical devices.Modern radiation treatments have become fairly complex and involve in utilizing a variety of medical devices to achieve the goal of providing conformal radiation dose coverage to the tumor target(s)while maximizing the sparing of normal organ structures.Recently,different forms of linear accelerators/radioactive source based machines have been invented and developed with the aim of providing improved treatments and more treatment options.Besides linear accelerators(Linac)that have been undergoing constant improvement and advancement and can deliver fairly complicated dose distribution patterns,imaging systems,computer information and calculation systems have been more and more integrated into radiotherapy processes.To bring radiotherapy to a potentially higher level,many institutions have either acquired or started to consider particle therapy,especially proton therapy.The complexity of modern radiotherapy demands in-depth understanding of radiation physics and machine engineering as well as computer information systems.This paper is intended to provide an introductory description of radiation oncology and related procedures,and to provide an overview of the current status of medical devices in radiotherapy in the United States of America.This paper covers the radiation delivery systems,imaging systems,treatment planning systems,record and verify systems,and QA systems.