Does participation in clinical trials influence the implementation of new techniques? A look at changing techniques in breast radiotherapy in the UK

Breast clinical target volume: HU-based glandular CTVs and ESTRO CTVs in modern and historical radiotherapy treatment planning

PURPOSE

The current study aimed to compare contouring of glandular tissue only (gCTV) with the clinical target volume (CTV) as defined according to European Society for Radiotherapy and Oncology (ESTRO) guidelines (eCTV) and historically treated volumes (marked by wire and determined by palpation and anatomic landmarks) in breast cancer radiotherapy.

METHODS

A total of 56 consecutive breast cancer patients underwent treatment planning based solely on anatomic landmarks/wire markings ("wire based"). From these treatment plans, the 50% and 95% isodoses were transferred as structures and compared to the following CT-based volumes: eCTV; a Hounsfield unit (HU)-based automatic contouring of the gCTV; and standardized planning target volumes (PTVs) generated with 1‑cm safety margins (resulting in the ePTVs and gPTVs, respectively).

RESULTS

The 95% isodose volume of the wire-based plan was larger than the eCTV by 352.39 ± 176.06 cm³ but smaller than the ePTV by 157.58 ± 189.32 cm³. The 95% isodose was larger than the gCTV by 921.20 ± 419.78 cm³ and larger than the gPTV by 190.91 ± 233.49 cm³. Patients with larger breasts had significantly less glandular tissue than those with small breasts. There was a trend toward a lower percentage of glandular tissue in older patients.

CONCLUSION

Historical wire and anatomic landmarks-based treatment planning sufficiently covers the glandular tissue and the theoretical gPTV generated for the glandular tissue. Modern CT-based CTV and PTV definition according to ESTRO results in a larger treated volume than the historical wire-based techniques. HU-standardized glandular tissue contouring results in a significantly smaller CTV and might be an option for reducing the treatment volume and improving reproducibility of contouring between institutions.

Ten-Year Results of FAST: A Randomized Controlled Trial of 5-Fraction Whole-Breast Radiotherapy for Early Breast Cancer

PURPOSE

Previous studies of hypofractionated adjuvant whole-breast radiotherapy for early breast cancer established a 15- or 16-fraction (fr) regimen as standard. The FAST Trial (CRUKE/04/015) evaluated normal tissue effects (NTE) and disease outcomes after 5-fr regimens. Ten-year results are presented.

METHODS

Women ≥ 50 years of age with low-risk invasive breast carcinoma (pT1-2 pN0) were randomly assigned to 50 Gy/25 fr (5 weeks) or 30 or 28.5 Gy in 5 once-weekly fr of 6.0 or 5.7 Gy. The primary end point was change in photographic breast appearance at 2 and 5 years; secondary end points were physician assessments of NTE and local tumor control. Odds ratios (ORs) from longitudinal analyses compared regimens.

RESULTS

A total of 915 women were recruited from 18 UK centers (2004-2007). Five-year photographs were available for 615/862 (71%) eligible patients. ORs for change in photographic breast appearance were 1.64 (95% CI, 1.08 to 2.49; P = .019) for 30 Gy and 1.10 (95% CI, 0.70 to 1.71; P = .686) for 28.5 Gy versus 50 Gy. α/β estimate for photographic end point was 2.7 Gy (95% CI, 1.5 to 3.9 Gy), giving a 5-fr schedule of 28 Gy (95% CI, 26 to 30 Gy) estimated to be isoeffective with 50 Gy/25 fr. ORs for any moderate/marked physician-assessed breast NTE (shrinkage, induration, telangiectasia, edema) were 2.12 (95% CI, 1.55 to 2.89; P < .001) for 30 Gy and 1.22 (95% CI, 0.87 to 1.72; P = .248) for 28.5 Gy versus 50 Gy. With 9.9 years median follow-up, 11 ipsilateral breast cancer events (50 Gy: 3; 30 Gy: 4; 28.5 Gy: 4) and 96 deaths (50 Gy: 30; 30 Gy: 33; 28.5 Gy: 33) have occurred.

CONCLUSION

At 10 years, there was no significant difference in NTE rates after 28.5 Gy/5 fr compared with 50 Gy/25 fr, but NTE were higher after 30 Gy/5 fr. Results confirm the published 3-year findings that a once-weekly 5-fr schedule of whole-breast radiotherapy can be identified that appears to be radiobiologically comparable for NTE to a conventionally fractionated regimen.

Provision of Organ at Risk Contouring Guidance in UK Radiotherapy Clinical Trials

AIMS

Accurate delineation of organs at risk (OAR) is vital to the radiotherapy planning process. Inaccuracies in OAR delineation arising from imprecise anatomical definitions may affect plan optimisation and risk inappropriate dose delivery to normal tissues. The aim of this study was to review the provision of OAR contouring guidance in National Institute of Health Research Clinical Research Network (NIHR CRN) portfolio clinical trials.

MATERIALS AND METHODS

The National Radiotherapy Quality Trials Assurance (RTTQA) Group carried out a two-round Delphi assessment to determine which OAR descriptions provided optimal guidance.

RESULTS

Eighty-four clinical trials involving radiotherapy quality assurance were identified as either in recruitment or in setup within the NIHR CRN portfolio. Fifty-nine trials mandated OAR contouring. In total there were 412 OAR; 171 were uniquely named; 159 OAR had more than one name associated with a single structure, with the greatest nomenclature variation seen for the femoral head ± neck, the parotid gland, and bowel. The two-round Delphi assessment determined 42 OAR descriptions as providing optimal contouring guidance.

CONCLUSIONS

This study identified the need for OAR nomenclature and contouring guidance consistency across clinical trials. In response to this study and in conjunction with the Global Quality Assurance of Radiation Therapy Clinical Trials Harmonisation Group, the RTTQA Group is in collaboration with international partners to provide consensus recommendations for OAR delineation in clinical trials.

Assessment of contour variability in target volumes and organs at risk in lung cancer radiotherapy

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It aimed to examine if there’s any significant differences in TV & OAR contouring in lung trials QA.

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Statistically significant difference in trial protocol compliances of TV & OAR contouring existed.

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Trial protocol compliances of TV & OARs delineation can be identified through trial QA.

Aims

This study aimed to examine whether any significant differences existed in trial protocol compliance in target volumes (TV) and organs at risk (OARs) contouring amongst clinical oncologists specialised in lung cancer radiotherapy.

Materials/methods

Two lung radiotherapy trials that require all prospective investigators to submit pre-trial outlining quality assurance (QA) benchmark cases were selected. The contours from the benchmark cases were compared against a set of reference contours which were defined by the trial management group (TMG). In order to quantify the degree of variation in TV and OARs contouring, the matching index (MI), Dice coefficient (DICE), Jaccard index (JI), Van‘t Riet Index and geographical miss index (GMI) were calculated.

Results

A total of 198 structures contoured by 21 clinicians were collected from the outlining benchmark cases. There were 40 clinical target volumes (CTV), 32 spinal cord, 36 oesophagus, 36 heart and 54 lungs volumes included in the study. Analysis of the pre-trial benchmark cases revealed statistically significant differences (p ≤ 0.05) in trial protocol compliances between clinical oncologists’ target volume and organs at risk contours. Our results demonstrated that the lung contours had the highest level of conformity, followed by heart, CTV, spinal cord and oesophagus respectively.

Conclusions

This study showed that there was a statistically significant difference in trial protocol compliance for lung clinical oncologists’ TV and OARs contouring within the pre-trial QA benchmark cases. Trial protocol compliances of TV and OARs delineation can be identified through assessing outlining QA benchmark cases.

Driving developments in UK oesophageal radiotherapy through the SCOPE trials

BACKGROUND

The SCOPE trials (SCOPE 1, NeoSCOPE and SCOPE 2) have been the backbone of oesophageal RT trials in the UK. Many changes in oesophageal RT techniques have taken place in this time. The SCOPE trials have, in addition to adopting these new techniques, been influential in aiding centres with their implementation. We discuss the progress made through the SCOPE trials and include details of a questionnaire sent to participating centres. to establish the role that trial participation played in RT changes in their centre.

METHODS

Questionnaires were sent to 47 centres, 27 were returned.

RESULTS

100% of centres stated their departmental protocol for TVD was based on the relevant SCOPE trial protocol. 4DCT use has increased from 42 to 71%. Type B planning algorithms, mandated in the NeoSCOPE trial, were used in 79.9% pre NeoSCOPE and now in 83.3%. 12.5% of centres were using a stomach filling protocol pre NeoSCOPE, now risen to 50%. CBCT was mandated for IGRT in the NeoSCOPE trial. 66.7% used this routinely pre NeoSCOPE/SCOPE 2 which has risen to 87.5% in the survey.

CONCLUSION

The results of the questionnaires show how participation in national oesophageal RT trials has led to the adoption of newer RT techniques in UK centres, leading to better patient care.

Evaluation of DNA extraction kits and phylogenetic diversity of the porcine gastrointestinal tract based on Illumina sequencing of two hypervariable regions

A robust DNA extraction method is important to identify the majority of microorganisms present in environmental microbial communities and to enable a consistent comparison between different studies. Here, 15 manual and four automated commercial DNA extraction kits were evaluated for their efficiency to extract DNA from porcine feces and ileal digesta samples. DNA yield, integrity, and purity varied among the different methods. Terminal restriction fragment length polymorphism (T‐RFLP) and Illumina amplicon sequencing were used to characterize the diversity and composition of the microbial communities. We also compared phylogenetic profiles of two regions of the 16S rRNA gene, one of the most used region (V1–2) and the V5–6 region. A high correlation between community structures obtained by analyzing both regions was observed at genus and family level for ileum digesta and feces. Based on our findings, we want to recommend the FastDNA^™SPIN Kit for Soil (MP Biomedical) as a suitable kit for the analyses of porcine gastrointestinal tract samples.

Clinical impact of IMPORT HIGH trial (CRUK/06/003) on breast radiotherapy practices in the United Kingdom

OBJECTIVE

IMPORT HIGH is a multicentre randomized UK trial testing dose-escalated intensity-modulated radiotherapy (IMRT) after tumour excision in females with early breast cancer and higher than average local recurrence risk. A survey was carried out to investigate the impact of this trial on the adoption of advanced breast radiotherapy (RT) techniques in the UK.

METHODS

A questionnaire was sent to all 26 IMPORT HIGH recruiting RT centres to determine whether the trial has influenced non-trial breast RT techniques in terms of volume delineation, dosimetry, treatment delivery and verification. In order to compare the clinical practice of breast RT between IMPORT HIGH and non-IMPORT HIGH centres, parts of the Royal College of Radiologists (RCR) breast RT audit result were used in this study.

RESULTS

26/26 participating centres completed the questionnaire. After joining the trial, the number of centres routinely using tumour bed clips to guide whole-breast RT rose from 5 (19%) to 21 (81%). 20/26 (77%) centres now contour target volumes and organs at risk (OARs) in some or all patients compared with 14 (54%) before the trial. 14/26 (54%) centres offer inverse-planned IMRT for selected non-trial patients with breast cancer, and 10/14 (71%) have adopted the IMPORT HIGH trial protocol for target volume and OARs dose constraints. Only 2/26 (8%) centres used clip information routinely for breast treatment verification prior to IMPORT HIGH, a minority that has since risen to 7/26 (27%). Data on 1386 patients was included from the RCR audit. This suggested that more cases from IMPORT HIGH centres had surgical clips implanted (83 vs 67%), were treated using CT guided planning with full three-dimensional dose compensation (100 vs 75%), and were treated with photon boost RT (30 vs 8%).

CONCLUSION

The study suggests that participation in the IMPORT HIGH trial has played an important part in providing the guidance and support networks needed for the safe integration of advanced RT techniques, where appropriate, as a standard of care for breast cancer patients treated at participating cancer centres.

ADVANCES IN KNOWLEDGE

We investigated the impact of the IMPORT HIGH trial on the adoption of advanced breast RT techniques in the UK and the trial has influenced non-trial breast RT techniques in terms of volume delineation, dosimetry, treatment delivery and verification.

Inter-departmental dosimetry audits - development of methods and lessons learned

External dosimetry audits give confidence in the safe and accurate delivery of radiotherapy. In the United Kingdom, such audits have been performed for almost 30 years. From the start, they included clinically relevant conditions, as well as reference machine output. Recently, national audits have tested new or complex techniques, but these methods are then used in regional audits by a peer-to-peer approach. This local approach builds up the radiotherapy community, facilitates communication, and brings synergy to medical physics.