How Long Does Contouring Really Take? Results of the Royal College of Radiologists Contouring Surveys

AIMS

The success and safety of modern radiotherapy relies on accurate contouring. Understanding the time taken to complete radiotherapy contours is critical to informing workforce planning and, in the context of a workforce shortfall, advocating for investment in technology and multi-professional skills mix. We aimed to quantify the time taken to delineate target volumes for radical radiotherapy.

MATERIALS AND METHODS

The Royal College of Radiologists circulated two electronic surveys via email to all clinical oncology consultants in the UK. The individual case survey requested anonymous data regarding the next five patients contoured for radical radiotherapy. The second survey collected data on respondents' usual practice in radiotherapy contouring.

RESULTS

The median time to contour one radiotherapy case was 85 minutes (IQR = 50-131 minutes). Marked variability between and within tumour sites was evident: paediatric cancers took the most time (median = 210 minutes, IQR = 87.5 minutes), followed by head and neck and gynaecological cancers (median = 120 minutes, IQR = 71 and 72.5 minutes respectively). Breast cancer contouring required the least time (median = 43 minutes, IQR = 60 minutes). Radiotherapy technique, inclusion of nodes and 4D CT planning were associated with longer contouring times. A non-medical professional was involved in contouring in 65% of cases, but clinical oncology consultants were involved in target volume delineation in 90% of cases, and OARs in 74%. Peer review took place in 46% of cases with 56% of consultants reporting no time for peer review in their job plan.

CONCLUSION

Contouring for radical radiotherapy is complex and time-consuming, and despite increasing involvement of non-medical professionals, clinical oncology consultants remain the primary practitioners. Peer review practice is variable and time is often a limiting factor. Many factors influence the time required for contouring, and departments should take these factors and the need for peer-review into account when developing job plans.

OS03.5.A Corelation between longitudinal t2 MRI radiomic primary texture feature values and radiation dose in non-tumoral regions of the brain in paediatric brain tumours

BACKGROUND

Paediatric brain tumour survivors may have treatment toxicity associated with signal change on follow-up MRI. Quantitative MRI texture features can potentially be used as surrogates of the underlying tissue changes following radiation therapy.

MATERIAL AND METHODS

Longitudinal retrospective study in 51 paediatric primary brain tumours treated with photon (N=30) and proton (N=21) radiotherapy (RT). T2 MRI scans at baseline and multiple time point from the date of surgery to 2 years following radiotherapy were selected for the textural analysis. Scans were bias corrected, registered with the CT dose maps and with baseline scan for each patient using 3Dslicer. Regions of interest (ROI) of fixed diameter were drawn in 11 predetermined non-tumoral regions of brain including in peri-tumoural region (PTV). ROIs were placed in homogenous white/grey matter. Radiation dose was calculated in each of these 11 ROIs and texture features were extracted using pyradiomics. Data were analysed using machine learning and statistical analysis. General linear multivariate model was used to corelate primary texture features over period of 24 months and radiation dose, time, effect of dose*time together at each ROI separately.

RESULTS

There were Brainstem 4, Cerebellar19, Hemispheric cerebral 7 and Supratentorial midline 10 tumours. Median age at diagnosis was 8.26 years (range: 0–20). Median RT treatment dose was 28.52Gy (0-60Gy). Multivariate analysis shows significant corelation (p < 0.001) between radiation dose and longitudinal primary texture features in all 11ROIs. Time showed corelation with feature values only in 3 ROIs and dose* time showed corelation in 5ROIs. Primary (statistical) feature values showing consistent correlation with dose in all 11 ROIs over 24 months are total energy, 10%, 90%, energy, entropy, mean, median, and minimum.

CONCLUSION

Radiomic texture analysis is a promising modality to understand dose related textural changes in the normal part of brain in paediatric brain tumour patients treated with radiation therapy. Radiomic changes need to be related to neurological outcomes in future research.

Abstract P6-18-32: Profiling the early haematological dynamics and treatment modifications with palbociclib when used as first line treatment for ER-positive, HER2-negative metastatic breast cancer

Background: Palbociclib plus endocrine therapy (ET) significantly increases progression free survival compared to ET alone. Within PALOMA2 neutropenia was the most common AE and reason for dose reductions. No real data exists regarding dose reductions (DRs), dose interruptions (DIs), toxicities and benefits of palbociclib. Objective: To describe the early haematological dynamics, DRs/DIs with 1st line palbociclib in the context of a routine UK clinical practice. Methods: A prospective record was maintained of all patients with ER-positive, HER2-negative metastatic BC registered on the Pfizer patient programme at the Clatterbridge Cancer Centre NHS Foundation Trust. The clinical records of all patients commenced on treatment between April and December 2017 were reviewed, and clinico-pathological information, haematological data & toxicity data recorded. Data lock was 31st March 2018. Results: 48 patients received at least one cycle of treatment. The median age was 58, 29% (14/48) premenopausal & 71% (34/48) postmenopausal. 43% (21/48) had bone only disease with 42% (20/48) having visceral disease. The median number of cycles delivered 8 (range 2-11). DRs: 18/48 (38%) patients had a total of 21 DRs; 14/18 (78%) had 1 DR to 100mg; 1/18 (5%) 1 DR to 75mg; & 3/18 (17%) 2 DRs to 75mg. Reasons for DRs: 13 neutropenia, 2 leukopenia, 1 thrombocytopenia, 2 fatigue, 1 poor appetite, 1 sore mouth & 1 non-specially unwell. DIs: occurred in 24/48 patients (50%). Details of DRs/DIs by cycle will be presented. 85% (41 of 48) patients remain on treatment with 59% (24/41) on 125mg; 34% (14/41) on 100mg & 7% (3/41) on 75mg. FBC were available for 41/48 (85%) cases & dynamics considered over the first 6 cycles using FBC at the time of planned treatment delivery. Hb Baseline all patients (AP):129 (121 – 138), patients; patients with no dose reductions (NDR) 127 (123 – 139) & patient dose reduction (DR): 130 (118 – 136). Hb changes to cycles 2, 4 and 6 AP: 122 (115 – 131), 121 (116 – 127) and 125 (116 – 134); NDR:122 (110 - 135), 125 (117 - 127) and 131 (116 – 135); DR: 115 (112 - 120), 120 (115 - 124) and 122 (115 – 129). WCC Baseline AP: 6.8 (5.6 – 7.7); NDR: 7.2 (6.3 – 7.7); DR: 6.7 (5.2 – 7.7). WCC changes to cycles 2, 4 and 6 AP: 3.7 (2.9 – 4.4), 3.7 (3.1 – 4.4) and 3.3 (3 – 3.9); NDR: 3.5 (2.9 – 4.1), 3.6 (3.2 – 4.3) and 3.6 (3.1 – 4.1); DR: 2.1 (1.7 – 2.5), 4.3 (3 – 4.6) and 3.3 (2.8 – 3.5). ANC Baseline AP: 4.0 (3.2 – 5.1); NDR: 4.4 (3.4 – 5.0); DR: 3.6 (2.9 – 5.2). ANC changes to cycles 2, 4 and 6 AP: 1.5 (1.2 – 2.1), 1.7 (1.3 – 2.0) and 1.4 (1.2 – 1.9) NDR: 1.5 (1.1 – 2.1), 1.7 (1.4 – 2.0) and 1.3 (1.2 – 2.0); DR: 0.8 (0.6 – 0.8), 1.7 (1.2 – 2.3) and 1.4 (1.3 – 1.6). Plts Baseline AP: 298 (226 – 339), NDR: 252 (211 – 336); DR: 299 (253 – 339). Plt changes to cycles 2, 4 and 6 AP: 252 (198 – 310), 221 (186 – 259) and 200 (169 – 243). NDR: 249 (185 – 334), 229 (171 – 267) and 205 (177 – 263);DR: 208 (199 – 210), 216 (199 – 243) and 194 (162 -210). Conclusion: These initial real world data are consistent with the PALOMA2 data. Baseline WCC & ANC show no significant difference between NDR and DR cases. Updated data will be presented as well as outcome data for first time.

Citation Format: Bhojwani A, Flint H, Hall B, Wong H, Innes H, Cliff J, Ahmed E, Malik Z, O'Hagan J, Tolan S, Hall A, Hyatt K, Errington D, Alam F, Robson P, Thorp N, O'Reilly S, Law A, Cicconi S, Jackson R, Palmieri C. Profiling the early haematological dynamics and treatment modifications with palbociclib when used as first line treatment for ER-positive, HER2-negative metastatic breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-32.

Abstract P6-17-27: Real world experience of the medical and surgical management of HER2 positive early breast cancer treated with neoadjuvant trastuzumab and pertuzumab via the NHS England cancer drug fund

Background: Studies of neoadjuvant (NA) dual HER2 blockade with trastuzumab (T) and pertuzumab (P) in combination with chemotherapy (CT) for early breast cancer (BC) have reported pathological complete response (pCR) rates of 39 to 62%. These studies also report manageable toxicity with diarrhoea reported in up to 73% of cases. To date no real-world studies have explored the efficacy and toxicity of this treatment. The objective of this study was to describe the medical and surgical management of women treated with neoadjuvant T-P in combination with CT (NAT-P-CT). As well as to determine the efficacy toxicity of NAT-P-CT in the context of a routine UK NHS clinical practice.

Methods: Patients with HER2+ BC treated neoadjuvantly with T-P accessed via the NHS England Cancer Drug Fund (CDF) at the Clatterbridge Cancer Centre NHS Foundation Trust between October 2016 and January 2018 were retrospectively identified. Clinico-pathological information, treatment data, nurse led toxicity review and echocardiographic were reviewed. Data lock was 19th June 2018.

Results: 78 female patients were identified with a median age of 50 years (IQR: 44.4-60.2). At diagnosis: median tumour size 30mm (23.0-47.5mm), 62% (48/78) were LN positive & 56% (44/78) ER+. CT regimens: 81% (63/78) FEC-DHP of these 30% (19/63) switched to weekly paclitaxel (wP). or nab-paclitaxel; 5% (4/78); AC/EC-DHP; 9% (8/78) TCHP with 13% (1/8) switched to wP. At time of analysis, 88% (69/78) had undergone definitive surgery. Surgical details: Breast: 52% (36/69) mastectomy & 48% (33/69) WLE, Axillary management: 51% (35/69) axillary dissection (Ax Dx) & 49% (34/69) sentinel node biopsy (4 performed prior to NA treatment). 91% (32/35) of those undergoing Ax Dx were LN+ at presentation, of these 59% (19/32) had no evidence of axillary involvement at surgery. pCR rate (ypT0/is, N0) was 46% (32/69) [pCR by HR: ER+ 43% (21/49) & ER- 55% (11/20]. pCR for 20 patients switched to wP was 60% (12/20). 7% (5/69) achieved pCR in the breast alone (in these LN status ITCx1, micrometsx3 & macrometsx1). Of the 54% (37/69) with residual breast tumour median size was 13mm (1-22mm). Toxicity Data: Ejection fraction (EF) did not decline beyond 10% of baseline in any patients. Diarrhoea (any grade) occurred in 74% of cases, and CTCAE grade 3-4 toxicity occurring in >2% of patients: diarrhoea, fatigue, and infection. Updated analysis regarding pCR rate and toxicity, as well as initial outcome data will be presented.

Conclusion: These results (1) confirm the efficacy of NA T-P in a real world population; (2) support the use of NA wP; (3) indicate significant proportion of patients axilla are downstaged & (4) reveal diarrhoea rates in keeping with the literature. Currently, NHS England rules do not allow wP to be used routinely in NA setting with T-P this should be reviewed in light of these data and those of the BERENICE study. Measures to identify patients who can avoid axillary dissection as well as to mitigate diarrhoea should be considered.

Citation Format: Hall B, Bhojwani A, Innes H, Ahmed E, Cliff J, Malik Z, O'Hagan J, Tolan S, Hall A, Hayat K, Errington D, Alam F, Thorp N, Flint H, Law A, Wong H, O'Reilly S, Jackson R, Cicconi S, Palmieri C. Real world experience of the medical and surgical management of HER2 positive early breast cancer treated with neoadjuvant trastuzumab and pertuzumab via the NHS England cancer drug fund [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-27.

Management of Ependymoma in Children, Adolescents and Young Adults

Paediatric ependymomas are rare, malignant tumours arising throughout the central nervous system, but most frequently (in children) the posterior fossa. The standard of care for localised disease is gross total resection and focal radiotherapy, resulting in overall survival rates of up to 85%. Despite improvements in survival, treatment remains challenging, with persistently high rates of (rarely curable) relapse alongside risks of significant tumour and treatment-related toxicity. Systemic therapy is currently used to delay radiotherapy in very young children and in the management of metastatic or recurrent disease. Its use in the adjuvant setting is the subject of ongoing studies. Current research efforts are aimed at eliciting a better understanding of molecular biology, correlating this with tumour behaviour and defining targets for potential new agents. Prognosis seems to be related to the extent of surgical resection and the age at presentation. This article reviews clinical aspects of ependymoma management in children and young people.

Abstract P5-15-07: Knowledge of oncotype Dx recurrence score increases confidence and concordance in adjuvant decisions of U.K. oncologists

Introduction

The addition of Oncotype Dx Recurrence Score (RS) to the assessment of patients with ER positive, HER2 negative, node negative breast cancer has led to a reduction in the use of adjuvant chemotherapy. However, crude measurement of this reduction masks a more complex scenario. Prior to the introduction of routine Oncotype DX testing by NHS England, we wished to explore in more detail the potential impact of the knowledge of the RS on the therapeutic discussion. This study analyses the impact of RS on the adjuvant therapy recommendations within a UK Cancer Centre. In particular, it examines how the degree of certainty the oncologist has about the best option changes with knowledge of RS and how this influences concordance of decision making between oncologists.

Methods

A panel of five breast oncologists reviewed 50 consecutive cases, collected from November 2012 until November 2014, across two hospitals. Oncologists allocated each case to one of four treatment categories: chemotherapy recommended (CRec), chemotherapy discussed with a bias towards recommended (CDis), chemotherapy discussed with a bias toward endocrine therapy alone (EDis) or endocrine therapy only advised (ERec). The cases were analysed blindly and in random order without and with RS . The degree to which knowledge of RS altered treatment recommendation was analyzed. Other outcomes included the proportion of patients who were scored ERec compared with any other outcome, the trend towards definitive recommendations, the impact of RS on concordant decision making and the degree to which outcome was stratified by RS result. Chi squared and Spearman's coefficient statistical tests were used in analysis.

Results

Knowledge of the RS altered the recommended treatment category in 66.7% of cases (p<0.001).

Alterations in treatment recommendations in response to Oncotype Recurrence Score in addition to pathological parameters CRec (n)CDis (n)EDis (n)ERec (n)Without RS2% (1)40% (20)52% (26)6% (3)With RS12% (6)16% (8)26% (13)46% (23)

Overall, RS correlated significantly with treatment recommendation. Oncologists were confident to recommend endocrine therapy alone in 46% of patients when RS was known compared with only 6% of patients without RS. Complete concordance between oncologists increased with the knowledge of RS from 14% to 64%.

Conclusion

Discussion of adjuvant chemotherapy with patients who have ER positive, HER2 negative, node negative breast cancer can be complex and, at times, confusing for the patient, leading to increased distress. This study shows that, in addition to the previously recognised reduction in overall use of chemotherapy, the knowledge of the RS increased the proportion of patients for whom the oncologist felt confident in making a firm treatment recommendation. An added benefit was to increase concordance between different oncologists compared to that achieved when relying on standard pathological features.

Citation Format: Kiernan T, Olsson-Brown AC, Innes H, Holcombe C, Thorp N, O'Hagan J, Wong H, Palmieri C, O'Reilly S. Knowledge of oncotype Dx recurrence score increases confidence and concordance in adjuvant decisions of U.K. oncologists. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-15-07.

Basic principles of paediatric radiotherapy

This article gives an introduction to the fundamentals of paediatric radiotherapy, describing the historical development of the speciality and its organisation in the UK, the clinical pathway (including issues around immobilisation) and an overview of indications for radiotherapy in the paediatric population. Late effects of radiotherapy, their mitigation and the role of the late effects clinic are summarised.

Lapatinib and trastuzumab in combination with an aromatase inhibitor for the first-line treatment of metastatic hormone receptor-positive breast cancer which over-expresses human epidermal growth factor 2 (HER2): a systematic review and economic analysis

BACKGROUND

Breast cancer is the uncontrolled, abnormal growth of malignant breast tissue affecting predominantly women. Metastatic breast cancer (mBC) is an advanced stage of the disease when the disease has spread beyond the original organ. Hormone receptor status and human epidermal growth factor 2 (HER2) status are two predictive factors that are taken into consideration when estimating the prognosis of patients with breast cancer.

OBJECTIVES

To review the clinical effectiveness and cost-effectiveness evidence base for lapatinib (LAP) in combination with an aromatase inhibitor (AI) and trastuzumab (TRA) in combination with an AI for the first-line treatment of patients who have hormone receptor-positive (HR+)/human epidermal growth factor 2-positive (HER2+) mBC.

DATA SOURCES

Relevant electronic databases and websites, including MEDLINE, EMBASE and the Cochrane Library, were searched until May 2010. Further data were derived from the manufacturers' submissions for LAP + AI and TRA + AI.

REVIEW METHODS

A systematic review of the clinical effectiveness and cost-effectiveness of LAP + AI and TRA + AI was undertaken. As it was deemed inappropriate to compare LAP + AI with TRA + AI, two separate assessments of cost-effectiveness versus AIs alone were undertaken.

RESULTS

Three trials were included in the systematic review [the patient populations of the efficacy and safety of lapatinib combined with letrozole (EGF30008) trial, the efficacy and safety of trastuzumab combined with anastrozole (TAnDEM) trial and the efficacy and safety of letrozole combined with trastuzumab (eLEcTRA) trial]. As a result of differences in the exclusion criteria and because one trial was halted prematurely, comparisons across trials were believed to be inappropriate and meta-analysis was not possible. Individually, however, the findings from the trials all suggest that LAP + AI or TRA + AI results in improved progression-free survival and/or time to progression when compared with AIs alone. The trials do not show a statistically significant benefit in terms of overall survival. Two separate economic analyses were conducted based on the completed trials; neither LAP + AI nor TRA + AI was found to be cost-effective when compared with AI monotherapy.

LIMITATIONS

Because of differences in the EGF30008 and the TAnDEM trials, the Assessment Group believes the indirect comparisons analyses conducted by the manufacturers are inappropriate and, for the same reason, chooses not to compare LAP + AI with TRA + AI in an economic evaluation.

CONCLUSIONS

LAP + AI and TRA + AI appear to be clinically more effective than AI monotherapy, but neither is cost-effective compared with AIs alone. It was not possible to compare LAP + AI with TRA + AI. Future research should include research into treating mBC in the HR+/HER2+ population who are not TRA (or LAP) naive and into comparing the clinical effectiveness of AIs as monotherapy in patients with HER2+ and human epidermal growth factor 2-negative breast cancer.

FUNDING

The National Institute for Health Research Technology Assessment programme.

The World Library of Toxicology, Chemical Safety, and Environmental Health (WLT)

The World Library of Toxicology, Chemical Safety, and Environmental Health, commonly referred to as the World Library of Toxicology (WLT), is a multilingual online portal of links to key global resources, representing a host of individual countries and multilateral organizations. The Site is designed as a network of, and gateway to, toxicological information and activities from around the world. It is built on a Wiki platform by a roster of Country Correspondents, with the aim of efficiently exchanging information and stimulating collaboration among colleagues, and building capacity, with the ultimate objective of serving as a tool to help improve global public health. The WLT was publicly launched on September 7, 2009, at the Seventh Congress of Toxicology in Developing Countries (CTDC-VII) in Sun City, South Africa.

Primary postoperative chemotherapy without radiotherapy for treatment of brain tumours other than ependymoma in children under 3 years: results of the first UKCCSG/SIOP CNS 9204 trial

BACKGROUND

Radiotherapy is an effective adjuvant treatment for brain tumours arising in very young children, but it has the potential to damage the child's developing nervous system at a crucial time - with a resultant reduction in IQ leading to cognitive impairment, associated endocrinopathy and risk of second malignancy. We aimed to assess the role of a primary chemotherapy strategy in avoiding or delaying radiotherapy in children younger than 3 years with malignant brain tumours other than ependymoma, the results of which have already been published.

METHODS

Ninety-seven children were enrolled between March 1993 and July 2003 and, following diagnostic review, comprised: medulloblastoma (n=31), astrocytoma (26), choroid plexus carcinoma [CPC] (15), CNS PNET (11), atypical teratoid/rhabdoid tumours [AT/RT] (6) and ineligible (6). Following maximal surgical resection, chemotherapy was delivered every 14 d for 1 year or until disease progression. Radiotherapy was withheld in the absence of progression.

FINDINGS

Over all diagnostic groups the cumulative progression rate was 80.9% at 5 years while the corresponding need-for-radiotherapy rate for progression was 54.6%, but both rates varied by tumour type. There was no clear relationship between chemotherapy dose intensity and outcome. Patients with medulloblastoma presented as a high-risk group, 83.9% having residual disease and/or metastases at diagnosis. For these patients, outcome was related to histology. The 5-year OS for desmoplastic/nodular medulloblastoma was 52.9% (95% confidence interval (CI): 27.6-73.0) and for classic medulloblastoma 33.3% (CI: 4.6-67.6); the 5-year EFS were 35.3% (CI: 14.5-57.0) and 33.3% (CI: 4.6-67.6), respectively. All children with large cell or anaplastic variants of medulloblastoma died within 2 years of diagnosis. The 5-year EFS for non-brainstem high-grade gliomas [HGGs] was 13.0% (CI: 2.2-33.4) and the OS was 30.9% (CI: 11.5-52.8). For CPC the 5-year OS was 26.67% (CI: 8.3-49.6) without RT. This treatment strategy was less effective for AT/RT with 3-year OS of 16.7% (CI: 0.8-51.7) and CNS PNET with 1-year OS of 9.1% (CI: 0.5-33.3).

INTERPRETATION

The outcome for very young children with brain tumours is dictated by degree of surgical resection and histological tumour type and underlying biology as an indicator of treatment sensitivity. Overall, the median age at radiotherapy was 3 years and radiotherapy was avoided in 45% of patients. Desmoplastic/nodular sub-type of medulloblastoma has a better prognosis than classic histology, despite traditional adverse clinical features of metastatic disease and incomplete surgical resection. A subgroup with HGG and CPC are long-term survivors without RT. This study highlights the differing therapeutic challenges presented by the malignant brain tumours of early childhood, the importance of surgical approaches and the need to explore individualised brain sparing approaches to the range of malignant brain tumours that present in early childhood.

Management strategies for recurrent ependymoma in the paediatric population

INTRODUCTION

The management of recurrent ependymoma within the paediatric population remains a therapeutic challenge. The options available are varied and patients may have already received prior radio- or chemotherapy. As yet, no consensus exists regarding their optimal treatment. We review the literature and present our contemporary management strategies for this interesting group of patients.

RESULTS AND DISCUSSION

Survival following recurrence is poor and those prognostic factors that predispose to recurrence include extent of surgical resection and the timing of administration of adjuvant therapy. The extent of resection at re-operation can confer a survival advantage, without a necessary increase in morbidity. Strategies aimed at improving surgical resection at first diagnosis include improving and centralising post-surgical radiological review, defining what are true residuals, and centralising surgical review of incompletely resected tumours. Re-irradiation can improve survival, and with the use of conformal radiation fields need not necessarily lead to neuropsychological damage. Cisplatin and etoposide remain the most effective chemotherapeutic agents to date and with an increase in the understanding of tumour biology this may improve further. Because of the complex nature of this group of patients, decisions regarding their management require the involvement of a paediatric neurosurgeon, paediatric neuro-oncologist and paediatric radiation oncologist.

Oil Film Thickness and Shape for a Ball Sliding in a Grooved Raceway

The behavior in the lubricated contact area of a driven ball sliding in a conforming glass groove, is studied. Interferometry is used to measure the oil film. Coupled ball surface velocity components are provided by angling the drive, while loads and speeds are varied in order to cover a range of conditions from undistorted surfaces to elastohydrodynamic lubrication. A general theory for lubrication with, no distortion and pressure-dependent viscosity, is developed and compared with experiment. Ball spin is found to have only a small effect on the oil film thickness.