Safety Of Radiotherapy In Patients Research Articles

PO-632-06 REAL-TIME EX-VIVO RADIOTHERAPY IMPACTS ON PACEMAKER FUNCTION ARE MINIMAL

There is a paucity of data regarding the safety of radiotherapy in patients with pacemakers and the impact of linear accelerator parameters is unclear. To assess the function of pacemakers when exposed to different linear accelerator parameters. Pacemakers (2 single, 1 dual chamber) were exposed to radiation at dose rates 0.2-11.8Gy/min. Dose rate was modulated by adjusting the distance from the beam edge, linear accelerator pulse repetition rate (rep rate) and distance from source. Noise amplitude, pacemaker output, and device behavior during irradiation were assessed in VVI or DDD modes. Each device was irradiated 28 times for 10 seconds. Noise amplitude on bipolar (Bi) channel increased with dose rate (r2=0.3611, p<0.0001, B) and on unipolar (Uni) channel decreased with rep rate (r2 = 0.09, p<0.01; C). On both channels noise amplitude decreased with distance from field edge (Bi r2 = 0.53, p<0.01; Uni r2 = 0.42, p<0.01; D). No over-sensed events occurred in response to radiation induced background noise. Low frequency signals on the Uni and Bi channels were observed with beam on and off (E), resulting in over-sensed events only when directly in the radiation beam and sensing Uni. When directly in the beam, oversensing of A pacing on the V sensing Uni channel was observed leading to pacing inhibition (F). Post-radiation exposure interrogation was unremarkable revealing no evidence of device malfunction. Pacemaker malfunctions when directly in photon radiation beam are related to oversensing and crosstalk phenomena preferentially affecting the unipolar sensing channel. There was no evidence of long-term device malfunction upon repeated interrogations despite multiple exposures.

Safety of radiotherapy in patients with Behcet’s disease: a case report and review of the literature

Exaggerated acute and late toxicities following radiotherapy have been reported in patients with pre-existing connective tissue diseases, such as systemic lupus and scleroderma. Behcet’s disease (BD) is a relapsing multisystem connective tissue disease characterized by vasculitis in the mucocutaneous, ocular, gastrointestinal, respiratory, neurologic, urogenital, articular, and cardiovascular systems. Data concerning the relationship between radiotherapy toxicity and BD are limited in the literature. Here, we report a case of lung cancer treated with radiotherapy (60 Gy) in a patient with BD. No severe radiation-induced toxicity was observed. Radiation-induced toxicity in patients with BD has also been discussed.

Validation of sentinel lymph biopsy in patients with early stage vulvar cancer: A prospective trial of 1552 women (GROINSS-V II/GOG270)

Objective: The sentinel lymph node (SLN) procedure in vulvar cancer has become standard of care since our first GROINSS-V study reported a groin recurrence rate of 2.3%. In GROINSS-V II/GOG270, a study that investigated the safety of radiotherapy in patients with metastases in their SLN, all SLN-negative patients were registered in order to confirm our previous findings. Here we present the analysis of the patients with a negative SLN.

Curative-intent radiotherapy in patients with oligometastatic lesions from colorectal cancer: A single-center study.

The purpose of the present study was to investigate the efficacy and safety of radiotherapy for patients with oligometastases from colorectal cancer (CRC).This was a retrospective cross-sectional study. Patients with liver and/or lung oligometastatic lesions from CRC treated with curative-intent radiotherapy in West China Hospital, Sichuan University, between 2009 and 2013 were included. Radiotherapy modality included 3-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and stereotactic body radiation therapy (SBRT); simultaneous chemotherapies along with radiotherapy of metastasis were allowed. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan–Meier method. Local control (LC) rates, toxicities, and factors of prognostic significance were also assessed.A total of 40 CRC patients with 57 liver and/or lung oligometastatic lesions were included. Most of the patients (95%) had received at least 1 line of previous systemic chemotherapy. Among them, 19 patients with 26 lesions received 3D-CRT with a median dose of 51.5 Gy in 16.1 fractions, 7 patients with 11 lesions received IMRT with a median dose of 49.3 Gy in 10.4 fractions, and 14 patients with 20 lesions received SBRT with a median dose of 56.4 Gy in 6.7 fractions, respectively. The median follow-up time was 34 months (range, 9–86 months). Median OS and PFS for patients were 30.0 months [95% confidence interval (95% CI), 21.3–38.7] and 11.0 months (95% CI, 9–13), respectively. One, 3, and 5 years’ LC rates for metastasis were 63.2%, 24.6%, and 16.9%, respectively. In subgroup analysis, patients with metachronous metastases had longer OS (median, 41.0 months; 95% CI, 33.3–48.7) than patients with synchronous lesions (median, 17.0 months; 95% CI, 7.4–26.6, P = .001). All patients tolerated the radiation treatment well, and there was no treatment-related death. Multivariate analysis showed that number of metastasis lesions and simultaneous liver and lung metastases were potential survival predictors.The study demonstrated that curative radiotherapy might be a tolerable and potential alternative for the treatment of patients with liver and/or lung oligometastases from CRC, and patients with metachronous lesions might have better survival than those with synchronous lesions when treated with curative-intent radiotherapy.

Irradiation of pacemakers and cardio-defibrillators in patients submitted to radiotherapy: a clinical experience.

A prospective analysis was carried out on a group of irradiated patients with pacemakers or implantable cardioverter-defibrillators to identify any relationship between the various types of devices and physical and dosimetric parameters. Cardiac toxicity of the treatment was also investigated. Forty-five irradiated patients, implanted with pacemakers or implantable cardioverter-defibrillators, were prospectively investigated from 1999 to 2007. An analysis of radiation damage to pacemakers, depending on the geometric and dosimetric characteristics of the radiation beams, was carried out. The electric and magnetic fields of linear accelerators (LINACs) were measured to evaluate any interference. The calculation of dose received by pacemakers was evaluated by dose-volume histograms. No dysfunction was observed in any pacemaker, nor were the substitution times negatively affected. We did not find problems with the devices due to the interaction with the electromagnetic fields. Dose-volume histograms calculated for patients treated in regions close to devices (head & neck, thorax) showed an average maximum dose equal to 2.5 Gy for the head & neck area and equal to 1.8 Gy for the thoracic area. Acute (3 cases) and late (2 cases) cardiac events were observed only in 5 patients who underwent chemoradiation treatment, but no dysfunction was observed in any pacemaker. Our study confirms the safety of radiotherapy for patients implanted with pacemakers or implantable cardioverter-defibrillators but suggests that chemoradiation represents a probable risk factor for cardiac toxicity. Furthermore, all cardiac events were observed in patients treated in the head and'neck or left thoracic areas. A standardized protocol is advisable in order to improve patient control during the radiotherapy treatment. It is mandatory to calculate the dose received at the pacemaker/heart, even in the case of palliative treatment.

Efficacy and Safety of Short Course Carbon-ion Radiotherapy for Patients with Preoperative Pancreatic Cancer

Efficacy and Safety of Short Course Carbon-ion Radiotherapy for Patients with Preoperative Pancreatic Cancer

Irradiation of Pacemakers and Cardio-Defibrillators in Patients Submitted to Radiotherapy: A Clinical Experience

A prospective analysis was carried out on a group of irradiated patients with pacemakers or implantable cardioverter-defibrillators to identify any relationship between the various types of devices and physical and dosimetric parameters. Cardiac toxicity of the treatment was also investigated. Forty-five irradiated patients, implanted with pacemakers or implantable cardioverter-defibrillators, were prospectively investigated from 1999 to 2007. An analysis of radiation damage to pacemakers, depending on the geometric and dosimetric characteristics of the radiation beams, was carried out. The electric and magnetic fields of linear accelerators (LINACs) were measured to evaluate any interference. The calculation of dose received by pacemakers was evaluated by dose-volume histograms. No dysfunction was observed in any pacemaker, nor were the substitution times negatively affected. We did not find problems with the devices due to the interaction with the electromagnetic fields. Dose-volume histograms calculated for patients treated in regions close to devices (head & neck, thorax) showed an average maximum dose equal to 2.5 Gy for the head & neck area and equal to 1.8 Gy for the thoracic area. Acute (3 cases) and late (2 cases) cardiac events were observed only in 5 patients who underwent chemoradiation treatment, but no dysfunction was observed in any pacemaker. Our study confirms the safety of radiotherapy for patients implanted with pacemakers or implantable cardioverter-defibrillators but suggests that chemoradiation represents a probable risk factor for cardiac toxicity. Furthermore, all cardiac events were observed in patients treated in the head and'neck or left thoracic areas. A standardized protocol is advisable in order to improve patient control during the radiotherapy treatment. It is mandatory to calculate the dose received at the pacemaker/heart, even in the case of palliative treatment.

Pregnancy and radiotherapy: Management options for minimising risk, case series and comprehensive literature review

This article reviews the efficacy and safety of radiotherapy in patients with cancer who are pregnant. Our review provided extended follow-up results in nine cases, presents a technical discussion on measures taken to minimise foetal radiation exposure and provides a comprehensive summary of the literature. Nine patients who received radiotherapy while pregnant are described. The clinical presentation and outcomes of these and 100 additional cases identified on a systematic literature review are presented. Comparisons of scattered radiation doses from three linear accelerators are presented. The average maternal follow-up in our series was 8.9 years with one patient having a recurrence of their astrocytoma. In terms of foetal outcome, there were one death in utero, one elective termination of pregnancy and one on which no data were available. Six children, on whom long-term follow-up (average 10.3 years) was obtainable, were in good health. Overall, there had been 109 cases of radiotherapy in pregnancy that met our search criteria with 13 adverse outcomes and a median follow-up of 37 months. Comparisons of three linear accelerators demonstrated significant differences in the amount of scattered radiation to the abdominal surface. In summary radiotherapy during pregnancy can be associated with a significant number of adverse outcomes. While it may be difficult for a patient not to attribute these effects to radiotherapy, it is also difficult to define the mechanisms by which radiotherapy would have caused them, if that were the case.