Lone Gothard

Detection of defects in myocardial perfusion imaging in patients with early breast cancer treated with radiotherapy.

BACKGROUND AND PURPOSE To evaluate radiation-induced defects in myocardial perfusion imaging in early breast cancer patients treated with modern technique radiotherapy. PATIENTS AND METHODS Twenty-four patients with left-breast tumours and 12 control patients with right-breast tumours, relapse-free since treatment for primary disease, who had undergone radiotherapy at least 5 years previously and with no history of ischaemic heart disease prior to radiotherapy underwent study. In left-breast patients, at least 1 cm of heart was required to have been in the treatment field. Patients underwent cardiac assessment and single photon emission computerized tomography myocardial perfusion imaging. RESULTS Myocardial perfusion tracer uptake was abnormal in 17 (70.8%) left-breast and two (16.7%) right-breast patients (P = 0.002). Of the 17 abnormal scans in left-breast patients, abnormalities were confined to the cardiac apex in 16 patients, and perfusion defects were reversible (n = 7), fixed (n = 7) or mixed (n = 3). Reversible perfusion defects that were not confined to the cardiac apex were observed in two right-breast patients. Left ventricular ejection fraction was normal in all 33 patients in whom it was measured, and no myocardial perfusion abnormalities were judged to require treatment or follow-up. CONCLUSIONS In this selected study population modern technique radiotherapy to the left breast was associated with a significantly greater number of myocardial perfusion abnormalities than radiotherapy to the right breast. These abnormalities were both reversible and irreversible, suggesting that radiotherapy can lead to both myocardial damage and to epicardial coronary disease. With a minimum of 5 years follow-up since treatment, no abnormalities were considered to be clinically significant.

Non-randomised phase II trial of hyperbaric oxygen therapy in patients with chronic arm lymphoedema and tissue fibrosis after radiotherapy for early breast cancer

BACKGROUND Radiation-induced arm lymphoedema is a common and distressing complication of curative treatment for early breast cancer. Hyperbaric oxygen (HBO(2)) therapy promotes healing in bone rendered ischaemic by radiotherapy, and may help some soft-tissue injuries too, but is untested in arm lymphoedema. METHODS Twenty-one eligible research volunteers with a minimum 30% increase in arm volume in the years after axillary/supraclavicular radiotherapy (axillary surgery in 18/21 cases) were treated with HBO(2). The volunteers breathed 100% oxygen at 2.4 ATA for 100 min in a multiplace hyperbaric chamber on 30 occasions over a period of 6 weeks. The volume of the ipsilateral limb, measured opto-electronically by a perometer and expressed as a percentage of contralateral limb volume, was selected as the primary endpoint. A secondary endpoint was local lymph drainage expressed as fractional removal rate of radioisotopic tracer, measured using lymphoscintigraphy. RESULTS Three out of 19 evaluable patients experienced >20% reduction in arm volume at 12 months. Six out of 13 evaluable patients experienced a >25% improvement in (99)Tc-nanocolloid clearance rate from the ipsilateral forearm measured by quantitative lymphoscintigraphy at 12 months. Overall, there was a statistically significant, but clinically modest, reduction in ipsilateral arm volume at 12 months follow-up compared with baseline (P = 0.005). The mean percentage reduction in arm volume from baseline at 12 months was 7.51. Moderate or marked lessening of induration in the irradiated breast, pectoral fold and/or supraclavicular fossa was recorded clinically in 8/15 evaluable patients. Twelve out of 19 evaluable patients volunteered that their arms felt softer, and six reported improvements in shoulder mobility at 12 months. No significant improvements were noted in patient self-assessments of quality of life. CONCLUSION Interpretation is limited by the absence of a control group. However, measurement of limb volume by perometry is reportedly reliable, and lymphoscintigraphy is assumed to be operator-independent. Taking all data into account, there is sufficient evidence to justify a double-blind randomised controlled trial of hyperbaric oxygen in this group of patients.

Residual DNA and chromosomal damage in ex vivo irradiated blood lymphocytes correlated with late normal tissue response to breast radiotherapy

PURPOSE To test the association of DNA double-strand break (DSB) repair and chromosomal radiosensitivity in ex vivo irradiated blood lymphocytes with late-onset normal tissue responses following breast radiotherapy. METHODS Breast cancer patients with minimal (controls) or marked late radiotherapy changes (cases) were retrospectively selected. DSB were quantified by γH2AX/53BP1 immunofluorescence microscopy 0.5 and 24 h after exposure of unstimulated blood lymphocytes to 0.5 and 4 Gy X-rays, respectively. Chromosomal aberrations were scored in blood lymphocyte metaphases after 6 Gy X-rays. RESULTS Despite similar foci levels at 0.5 h in cases (n=7) and controls (n=7), foci levels 24 h after 4 Gy irradiation differed significantly between them (foci per cell were 12.8 in cases versus 10.2 in controls, p=0.004). Increased chromosomal radiosensitivity was also observed in cases (aberrations per cell were 5.84 in cases versus 3.79 in controls, p=0.001) with exchange and deletion type aberrations contributing equally to the difference between cases and controls. Residual foci correlated with formation of deletions (Spearmans R=0.589, p=0.027) but not exchanges (R=0.367, p=0.197) in blood lymphocytes from the same patients. CONCLUSIONS Higher levels of exchange type aberrations observed among radiosensitive breast cancer patients suggest a role for DSB misrepair, in addition to residual damage, as determinants of late normal tissue damage. Correlation of residual foci levels with deletion type aberration yields in the same cohort confirms their mechanistic linkage.

Lymphatic relapse in women with early breast cancer: a difficult management problem

The aim of this study was to review the ability to control symptoms of regional lymphatic relapse in women with early breast cancer. A retrospective study was made of 759 consecutive women presenting with stage 1 or 2 breast cancer treated by breast conserving surgery and radiotherapy between June 1984 and December 1994, 291 (38.3%) of whom were managed by a policy of observation on the lymphatic pathways. Patterns of lymphatic relapse, relapse management and morbidity caused by recurrent malignancy were reviewed from the case notes. The overall rate of relapse in the ipsilateral axilla and/or supraclavicular fossa was 76/759 (10%) at any time prior to death or last follow-up. 34 of 65 patients who relapsed in the axilla did so despite prior axillary surgery and/or radiotherapy. 41 of 76 patients with regional recurrence presented with symptoms, including lymphoedema, arm pain or sensory motor changes. These symptoms were poorly controlled by palliative surgery, radiotherapy or systemic therapy in 23 cases, including 12 who progressed to arm paralysis. Symptomatic control of patients with regional lymphatic relapse can be very difficult, even in women under regular surveillance in a multidisciplinary breast cancer clinic.

Randomised phase II trial of hyperbaric oxygen therapy in patients with chronic arm lymphoedema after radiotherapy for cancer.

BACKGROUND A non-randomised phase II study suggested a therapeutic effect of hyperbaric oxygen (HBO) therapy on arm lymphoedema following adjuvant radiotherapy for early breast cancer, justifying further investigation in a randomised trial. METHODS Fifty-eight patients with ≥ 15% increase in arm volume after supraclavicular ± axillary radiotherapy (axillary surgery in 52/58 patients) were randomised in a 2:1 ratio to HBO (n=38) or to best standard care (n=20). The HBO group breathed 100% oxygen at 2.4 atmospheres absolute for 100 min on 30 occasions over 6 weeks. Primary endpoint was ipsilateral limb volume expressed as a percentage of contralateral limb volume. Secondary endpoints included fractional removal rate of radioisotopic tracer from the arm, extracellular water content, patient self-assessments and UK SF-36 Health Survey Questionnaire. FINDINGS Of 53/58 (91.4%) patients with baseline assessments, 46 had 12-month assessments (86.8%). Median volume of ipsilateral limb (relative to contralateral) at baseline was 133.5% (IQR 126.0-152.3%) in the control group, and 135.5% (IQR 126.5-146.0%) in the treatment group. Twelve months after baseline the median (IQR) volume of the ipsilateral limb was 131.2% (IQR 122.7-151.5%) in the control group and 133.5% (IQR 122.3-144.9%) in the treatment group. Results for the secondary endpoints were similar between randomised groups. INTERPRETATION No evidence has been found of a beneficial effect of HBO in the treatment of arm lymphoedema following primary surgery and adjuvant radiotherapy for early breast cancer.

Evaluation of a method for grading late photographic change in breast appearance after radiotherapy for early breast cancer.

AIMS Serial photographs have been collected prospectively to evaluate the effect of radiotherapy on normal tissues in the breast. The aim of this study was to compare two methods of scoring radiation-induced changes. MATERIALS AND METHODS Five-year photographs of 400 patients randomised to receive either 42.9 or 39 Gy in 13 fractions to the whole breast after tumour excision of early breast cancer were compared with a post-surgery baseline and scored for change in breast appearance on a three-point graded scale. Two alternative methods of scoring using three observers were compared: (a) scores allocated independently, with independent resolution of discrepancies, and (b) scores allocated by consensus. RESULTS Treatment effects estimated from the consensus and independent scores were very similar (odds ratio 1.89, 95% confidence interval 1.21-2.96 vs 2.28, 95% confidence interval 1.50-3.47, respectively). Agreement between the scores obtained from each method was reasonable, and the repeatability of the consensus method was good. CONCLUSIONS The consensus method of scoring photographic change in breast appearance seems to be no less sensitive to randomised dose as the independent method of assessment, but is much quicker to administer. The consensus method has been used to score over 3000 sets of photographs in the National Cancer Research Institute Standardisation of Breast Radiotherapy trial.

The Relationship Between Homologous Recombination Repair and the Sensitivity of Human Epidermis to the Size of Daily Doses Over a 5-Week Course of Breast Radiotherapy

Purpose: A molecular understanding of tissue sensitivity to radiotherapy fraction size is missing. Here, we test the hypothesis that sensitivity to fraction size is influenced by the DNA repair system activated in response to DNA double-strand breaks (DSB). Human epidermis was used as a model in which proliferation and DNA repair were correlated over 5 weeks of radiotherapy. Experimental design: Radiotherapy (25 fractions of 2 Gy) was prescribed to the breast in 30 women with early breast cancer. Breast skin biopsies were collected 2 hours after the 1st and 25th fractions. Samples of contralateral breast skin served as controls. Sections were coimmunostained for Ki67, cyclin A, p21, RAD51, 53BP1, and β1-integrin. Results: After 5 weeks of radiotherapy, the mean basal Ki67 density increased from 5.72 to 15.46 cells per millimeter of basement membrane (P = 0.002), of which the majority were in S/G2 phase, as judged by cyclin A staining (P < 0.0003). The p21 index rose from 2.8% to 87.4% (P < 0.0001) after 25 fractions, indicating cell cycle arrest. By week 5, there was a 4-fold increase (P = 0.0003) in the proportion of Ki67-positive cells showing RAD51 foci, suggesting increasing activation of homologous recombination. Conclusions: Cell cycle arrest in S/G2 phase in the basal epidermis after a 5-week course of radiotherapy is associated with greater use of homologous recombination for repairing DSB. The high fidelity of homologous recombination, which is independent of DNA damage levels, may explain the low-fractionation sensitivity of tissues with high-proliferative indices, including self-renewing normal tissues and many cancers. Clin Cancer Res; 18(19); 5479–88. ©2012 AACR.

FDXR is a biomarker of radiation exposure in vivo

Previous investigations in gene expression changes in blood after radiation exposure have highlighted its potential to provide biomarkers of exposure. Here, FDXR transcriptional changes in blood were investigated in humans undergoing a range of external radiation exposure procedures covering several orders of magnitude (cardiac fluoroscopy, diagnostic computed tomography (CT)) and treatments (total body and local radiotherapy). Moreover, a method was developed to assess the dose to the blood using physical exposure parameters. FDXR expression was significantly up-regulated 24 hr after radiotherapy in most patients and continuously during the fractionated treatment. Significance was reached even after diagnostic CT 2 hours post-exposure. We further showed that no significant differences in expression were found between ex vivo and in vivo samples from the same patients. Moreover, potential confounding factors such as gender, infection status and anti-oxidants only affect moderately FDXR transcription. Finally, we provided a first in vivo dose-response showing dose-dependency even for very low doses or partial body exposure showing good correlation between physically and biologically assessed doses. In conclusion, we report the remarkable responsiveness of FDXR to ionising radiation at the transcriptional level which, when measured in the right time window, provides accurate in vivo dose estimates.

A randomized control trial evaluating fluorescent ink versus dark ink tattoos for breast radiotherapy

Objective: The purpose of this UK study was to evaluate interfraction reproducibility and body image score when using ultraviolet (UV) tattoos (not visible in ambient lighting) for external references during breast/chest wall radiotherapy and compare with conventional dark ink. Methods: In this non-blinded, single-centre, parallel group, randomized control trial, patients were allocated to receive either conventional dark ink or UV ink tattoos using computer-generated random blocks. Participant assignment was not masked. Systematic (∑) and random (σ) setup errors were determined using electronic portal images. Body image questionnaires were completed at pre-treatment, 1 month and 6 months to determine the impact of tattoo type on body image. The primary end point was to determine that UV tattoo random error (σsetup) was no less accurate than with conventional dark ink tattoos, i.e. <2.8 mm. Results: 46 patients were randomized to receive conventional dark or UV ink tattoos. 45 patients completed treatment (UV: n = 23, dark: n = 22). σsetup for the UV tattoo group was <2.8 mm in the u and v directions (p = 0.001 and p = 0.009, respectively). A larger proportion of patients reported improvement in body image score in the UV tattoo group compared with the dark ink group at 1 month [56% (13/23) vs 14% (3/22), respectively] and 6 months [52% (11/21) vs 38% (8/21), respectively]. Conclusion: UV tattoos were associated with interfraction setup reproducibility comparable with conventional dark ink. Patients reported a more favourable change in body image score up to 6 months following treatment. Advances in knowledge: This study is the first to evaluate UV tattoo external references in a randomized control trial.

Correlation between the radiation responses of fibroblasts cultured from individual patients and the risk of late reaction after breast radiotherapy

Late normal tissue toxicity varies widely between patients and limits breast radiotherapy dose. Here we aimed to determine its relationship to DNA damage responses of fibroblast cultures from individual patients. Thirty-five breast cancer patients, with minimal or marked breast changes after breast-conserving therapy consented to receive a 4 Gy test irradiation to a small skin field of the left buttock and have punch biopsies taken from irradiated and unirradiated skin. Early-passage fibroblast cultures were established by outgrowth and irradiated in vitro with 0 or 4 Gy. 53BP1 foci, p53 and p21/CDKN1A were detected by immunofluorescence microscopy. Residual 53BP1 foci counts 24 h after in vitro irradiation were significantly higher in fibroblasts from RT-sensitive versus RT-resistant patients. Furthermore, significantly larger fractions of p53- but not p21/CDKN1A-positive fibroblasts were found in cultures from RT-sensitive patients without in vitro irradiation, and 2 h and 6 d post-irradiation. Exploratory analysis showed a stronger p53 response 2 h after irradiation of fibroblasts established from patients with severe reaction. These results associate the radiation response of fibroblasts with late reaction of the breast after RT and suggest a correlation with severity.