Estimating the percentage of patients who might benefit from proton beam therapy instead of X-ray radiotherapy.

OBJECTIVES: High-energy Proton Beam Therapy (PBT) commenced in England in 2018 and NHS England commissions PBT for 1.5% of patients receiving radical radiotherapy. We sought expert opinion on the level of provision. METHODS: Invitations were sent to 41 colleagues working in PBT, most at one UK centre, to contribute by completing a spreadsheet. 39 responded: 23 (59%) completed the spreadsheet; 16 (41%) declined, arguing that clinical outcome data are lacking, but joined six additional site-specialist oncologists for two consensus meetings. The spreadsheet was pre-populated with incidence data from Cancer Research UK and radiotherapy use data from the National Cancer Registration and Analysis Service. 'Mechanisms of Benefit' of reduced growth impairment, reduced toxicity, dose escalation and reduced second cancer risk were examined. RESULTS: The most reliable figure for percentage of radical radiotherapy patients likely to benefit from PBT was that agreed by 95% of the 23 respondents at 4.3%, slightly larger than current provision. The median was 15% (range 4-92%) and consensus median 13%. The biggest estimated potential benefit was from reducing toxicity, median benefit to 15% (range 4-92%), followed by dose escalation median 3% (range 0 to 47%); consensus values were 12 and 3%. Reduced growth impairment and reduced second cancer risk were calculated to benefit 0.5% and 0.1%. CONCLUSIONS: The most secure estimate of percentage benefit was 4.3% but insufficient clinical outcome data exist for confident estimates. The study supports the NHS approach of using the evidence base and developing it through randomised trials, non-randomised studies and outcomes tracking. ADVANCES IN KNOWLEDGE: Less is known about the percentage of patients who may benefit from PBT than is generally acknowledged. Expert opinion varies widely. Insufficient clinical outcome data exist to provide robust estimates. Considerable further work is needed to address this, including international collaboration; much is already underway but will take time to provide mature data.

Optimizing MR-Guided Radiotherapy for Breast Cancer Patients.

Current research in radiotherapy (RT) for breast cancer is evaluating neoadjuvant as opposed to adjuvant partial breast irradiation (PBI) with the aim of reducing the volume of breast tissue irradiated and therefore the risk of late treatment-related toxicity. The development of magnetic resonance (MR)-guided RT, including dedicated MR-guided RT systems [hybrid machines combining an MR scanner with a linear accelerator (MR-linac) or 60Co sources], could potentially reduce the irradiated volume even further by improving tumour visibility before and during each RT treatment. In this position paper, we discuss MR guidance in relation to each step of the breast RT planning and treatment pathway, focusing on the application of MR-guided RT to neoadjuvant PBI.

Consensus on Contouring Primary Breast Tumors on MRI in the Setting of Neoadjuvant Partial Breast Irradiation in Trials.

PURPOSE: Our purpose was to present and evaluate expert consensus on contouring primary breast tumors on magnetic resonance imaging (MRI) in the setting of neoadjuvant partial breast irradiation in trials. METHODS AND MATERIALS: Expert consensus on contouring guidelines for target definition of primary breast tumors on contrast-enhanced MRI in trials was developed by an international team of experienced breast radiation oncologists and a dedicated breast radiologist during 3 meetings. At the first meeting, draft guidelines were developed through discussing and contouring 2 cases. At the second meeting 6 breast radiation oncologists delineated gross tumor volume (GTV) in 10 patients with early-stage breast cancer (cT1N0) according to draft guidelines. GTV was expanded isotropically (20 mm) to generate clinical target volume (CTV), excluding skin and chest wall. Delineations were reviewed for disagreement and guidelines were clarified accordingly. At the third meeting 5 radiation oncologists redelineated 6 cases using consensus-based guidelines. Interobserver variation of GTV and CTV was assessed using generalized conformity index (CI). CI was calculated as the sum of volumes each pair of observers agreed upon, divided by the sum of encompassing volumes for each pair of observers. RESULTS: For the 2 delineation sessions combined, mean GTV ranged between 0.19 and 2.44 cm3, CI for GTV ranged between 0.28 and 0.77, and CI for CTV between 0.77 and 0.94. The largest interobserver variation in GTV delineations was observed in cases with extended tumor spiculae, blood vessels near or markers within the tumor, or with increased enhancement of glandular breast tissue. Consensus-based guidelines stated to delineate all visible tumors on contrast enhanced-MRI scan 1 to 2 minutes after contrast injection and if a marker was inserted in the tumor to include this. CONCLUSIONS: Expert-based consensus on contouring primary breast tumors on MRI in trials has been reached. This resulted in low interobserver variation for CTV in the context of a uniform 20 mm GTV to CTV expansion margin.

The case for including bowel urgency in toxicity reporting after pelvic cancer treatment.

Bowel toxicity is a major complication of cancer treatment, and its accurate reporting is important for assessing outcomes. The NCI's Common Terminology Criteria for Adverse Events (CTCAE) is the preferred method for capturing adverse events after all cancer treatments, particularly within clinical trials. However, the CTCAE version 4 does not include urgency of defecation as an item, despite this being one of the most common and persistent adverse consequences of treatment of pelvic cancers. The importance of bowel urgency to patients is well documented, and this treatment effect has a negative impact on social function and quality of life. Bowel urgency is also important clinically because it may represent significant underlying problems. This article presents the case for including patient reported assessment of bowel urgency as an independent item in cancer treatment adverse event reporting.

Early prostate cancer--which treatment do men prefer and why?

STUDY TYPE: Preference (prospective cohort). LEVEL OF EVIDENCE: 1b. What's known on the subject? and What does the study add? In general the literature suggests that there is a need for improvement in aiding men diagnosed with early prostate cancer in their decision making about treatment options and that our understanding of this process is inadequate. There is limited data analyzing the reasons why these men decide between potentially curative or observational treatments and data evaluating patients' views before and after definitive therapy are scarce. This study begins the process of understanding the reasons underlying a patient's final treatment decision. Being a prospective study, it looks at the thought processes of these men before treatment during the time the decision is made. It also documents how satisfied patients are with their choice after their treatment and whether they would choose the same treatment again. OBJECTIVE: To identify the reasons for patients with localised prostate cancer choosing between treatments and the relationship of procedure type to patient satisfaction post-treatment. PATIENTS AND METHODS: 768 men with prostate cancer (stage T1/2, Gleason≤7, PSA<20 ug/L) chose between four treatments: radical prostatectomy, brachytherapy, conformal radiotherapy and active surveillance. Prior to choosing, patients were counselled by a urological surgeon, clinical (radiation) oncologist and uro-oncology specialist nurse. Pre-treatment reasons for choice were recorded. Post-treatment satisfaction was examined via postal questionnaire. RESULTS: Of the 768 patients, 305 (40%) chose surgery, 237 (31%) conformal beam radiotherapy, 165 (21%) brachytherapy and 61 (8%) active surveillance. Sixty percent of men who opted for radical prostatectomy were motivated by the need for physical removal of the cancer. Conformal radiotherapy was mainly chosen by patients who feared other treatments (n=63, 27%). Most men chose brachytherapy because it was more convenient for their lifestyle (n=64, 39%). Active surveillance was chosen by patients for more varied reasons. Post-treatment satisfaction was assessed in a subgroup who took part in the QOL aspect of this study. Of the respondents to the questionnaire, 212(87.6%) stated that they were satisfied/extremely satisfied with their choice and 171(92.9%) indicated they would choose the same treatment again. CONCLUSION: Men with early prostate cancer have clear reasons for making decisions about treatment. Overall, patients were satisfied with the treatment and indicated that despite different reasons for choosing treatment, they would make the same choice again.