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An increasing number of patients with implantable cardiac rhythm devices undergo radiotherapy (RT) for cancer and are thereby exposed to the risk of device failure. Current safety recommendations seem to have limitations by not accounting for the risk of pacemakers and implantable cardioverter defibrillators malfunctioning at low radiation doses. Besides scant knowledge about optimal safety measures, only little is known about the exact prevalence of patients with devices undergoing RT. In this review, we provide a short overview of the principles of RT and present the current evidence on the predictors and mechanisms of device malfunctions during RT. We also summarize practical recommendations from recent publications and from the industry. Strongly associated with beam energy of photon RT, device malfunctions occur at ∼3% of RT courses, posing a substantial issue in clinical practice. Malfunctions described in the literature typically consist of transient software disturbances and only seldom manifest as a permanent damage of the device. Through close cooperation between cardiologists and oncologists, a tailored individualized approach might be necessary in this patient group in waiting time for updated international guidelines in the field.

Pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) may develop malfunction during external beam radiotherapy (RT). We aimed to describe clinical practice in PM/ICD patients undergoing RT and to assess the rate and predictors of device malfunctions.We reviewed medical records of all PM/ICD patients undergoing RT at four centers in Western Denmark during 2003-2012. Logistic regression was applied to identify predictors of PM/ICD malfunctions.Five hundred sixty patients were included. The annual rate of RT courses in PM/ICD patients increased by 199% from 1.45 treatments per 100,000 person-years in 2003 to 4.33 in 2012. Safety measures included supplementary evaluations of PM/ICD (38.3%), reprogramming (1.5%), relocation of the device (3.5%), and application of a magnet to the ICD during RT (10.8%). At device evaluations after the RT (n = 453), malfunctions were detected in 10 (2.5%) PMs and four (6.8%) ICDs. Electrical resets constituted 11 (78.6%) of the malfunctions, and no failures were life-threatening or warranted PM/ICD removal. Factors associated with device malfunctions in logistic regression analysis were beam energy ≥15 MV (odds ratio [OR] 5.73; 95% confidence interval [CI], 1.58-20.76) and location of tumor below the diaphragm (OR 4.31; 95% CI, 1.42-13.12). However, the effect of tumor location declined (OR 2.27; 95% CI, 0.65-7.95) after adjustment for beam energy.Although the rate of RT in PM/ICD patients is increasing, the damaging effects of RT on the devices seem to be usually transient. Our data suggest that high beam energy plays the pivotal role in inducing impairments in these devices.

BACKGROUND: In radiotherapy (RT) of urinary bladder cancer, the use of intensity-modulated RT (IMRT) opens for sparing of considerable intestinal volumes. The purpose of the present study was to investigate the acute and late toxicities following either conformal RT (CRT) or IMRT for bladder cancer, and to correlate the toxicities to dose-volume parameters.MATERIAL AND METHODS: The study included 116 consecutively treated patients with muscle-invasive bladder cancer who received either CRT (n = 66) or IMRT (n = 50) during 2007-2010. Acute side effects were retrospectively collected whereas late effects were assessed by a cross-sectional evaluation by telephone interview of 44 recurrence-free patients. Acute and late toxicities were scored according to the Common Terminology Criteria for Adverse Event (CTCAE) version 3.0.RESULTS: Acute diarrhoea grade ≥ 2 was more frequent in patients treated by CRT (56%) compared to IMRT (30%) (p = 0.008). Logistic regression analysis showed a correlation between acute diarrhoea and bowel cavity dose-volume parameters in the 10-50 Gy range. Severe late toxicity (grade ≥ 3) was recorded in 10% of the total cohort, with no statistical difference between the IMRT and CRT groups.CONCLUSION: Patients treated with IMRT for bladder cancer had significantly less acute diarrhoea compared to those treated with CRT, but there was no significant difference in late morbidity between the groups. The risk of acute diarrhoea was related to the volume of bowel irradiated.

With an ageing population an increasing number of patients with a pacemaker or implantable cardioverter defibrillator will present at radiotherapy units due to malignancy. Two separate questionnaires concerning routines of departments treating this population were sent to Danish implanting cardiology centers and to radiotherapy departments. Differences in the handling of these patients were found. Removal of the devices and monitoring of the patients is assessed on a highly individual basis. In the absence of updated official guidelines, departments treating these patients should produce local instructions.

Capecitabine is an oral prodrug to 5-fluorouracil (5-FU). The primary target of 5-FU is thymidylate synthase (TS). A mainstay of colorectal adenocarcinoma chemotherapy is inhibition of TS, which may be one of many determinant factors when predicting the outcome of chemotherapies based on fluoropyrimidine treatment. This retrospective study included 39 patients with advanced colorectal adenocarcinoma treated with capecitabine. Response was assessed by measuring the amount of tumour in the course of treatment. TS expression was evaluated by scoring the immunohistochemical (IHC) reaction and assessing the predominant IHC reaction pattern. This study showed significant correlation between the predominant IHC reaction pattern and response, but no correlation between IHC score and response. The predominant IHC reaction pattern may be a useful parameter in prediction of clinical outcome in patients treated with capecitabine.

Udgivelsesdato: 2010