Prostate Volume Changes during Extreme and Moderately Hypofractionated Magnetic Resonance Image-guided Radiotherapy

AIMS

Prostate morphological changes during external beam radiotherapy are poorly understood. Excellent soft-tissue visualisation offered by magnetic resonance image-guided radiotherapy (MRIgRT) provides an opportunity to better understand such changes. The aim of this study was to quantify prostate volume and dimension changes occurring during extreme and moderately hypofractionated schedules.

MATERIALS AND METHODS

Forty prostate cancer patients treated on the Unity 1.5 Tesla magnetic resonance linear accelerator (MRL) were retrospectively reviewed. The cohort comprised patients treated with 36.25 Gy in five fractions (n = 20) and 60 Gy in 20 fractions (n = 20). The volume of the delineated prostates on reference planning computed tomography (fused with MRI) and daily T2-weighted 2-min session images acquired on Unity were charted. Forty planning computed tomography and 500 MRL prostate volumes were evaluated. The mean absolute and relative change in prostate volume during radiotherapy was compared using a paired t-test (P value <0.01 considered significant to control for multiple comparisons). The maximum dimension of the delineated prostate was measured in three isocentric planes.

RESULTS

Significant prostate volume changes, relative to MRL imaging fraction 1 (MRL#1), were seen at all time points for the five-fraction group. The peak mean relative volume increase was 21% (P < 0.001), occurring at MRL#3 and MRL#4 after 14.5 and 21.75 Gy, respectively. Prostate expansion was greatest in the superior-inferior direction; the peak mean maximal extension was 5.9 mm. The maximal extension in the left-right and anterior-posterior directions measured 1.1 and 2.2 mm, respectively. For the 20-fraction group, prostate volume increased relative to MRL#1, for all treatment time points. The mean relative volume increase was 11% (P < 0.001) at MRL#5 after 12 Gy, it then fluctuated between 8 and 13%. From MRL#5 to MRL#20, the volume increase was significant (P < 0.01) for 12 of 16 time points calculated. The peak mean maximal extension in the superior-inferior direction was 3.1 mm. The maximal extension in the left-right and anterior-posterior directions measured 1.7 and 3.7 mm, respectively.

CONCLUSION

Significant prostate volume and dimension changes occur during extreme and moderately hypofractionated radiotherapy. The extent of change was greater during extreme hypofractionation. MRIgRT offers the opportunity to reveal, quantify and correct for this deformation.

Evaluation of a urology specialist therapeutic radiographer implemented radiotherapy pathway for prostate cancer patients

INTRODUCTION

The role of the Urology Specialist Therapeutic Radiographer (USTR) was introduced to support a busy NHS uro-oncology practice. Key objectives were to improve patient preparedness for and experience of radiotherapy, focussed on prostate cancer. Pre-radiotherapy information seminars were developed, and on-treatment patient review managed by the USTRs. To evaluate the revamped patient pathway and direct further improvements, a patient experience survey was designed.

METHODS

An 18-point patient questionnaire was produced. The questionnaire captured patient experience and preparedness; pre, during and at completion of treatment. The patient population comprised men receiving radiotherapy for primary prostate cancer within one UK Trust.

RESULTS

Two-hundred and fifty-one responses were received. Seventy-three percent of patients felt completely prepared for radiotherapy, higher in those who attended a seminar (77%) compared to those who did not (61%). Eighty-nine and eighty-six percent of respondents were completely satisfied with verbal and written information received prior to commencing radiotherapy respectively. Seventy-three percent of responders would have found additional resources helpful. With respect to on-treatment clinics; eighty-five percent were seen on time or within 20 minutes, eighty-three percent felt fully involved in decisions regarding their care and ninety-one percent reported complete satisfaction with the knowledge of the health care professional reviewing them. The follow-up process was completely understood by eighty-eight percent and overall patient experience rated excellent by eighty-five percent of responders.

CONCLUSION

The revamped pathway implemented by USTRs has achieved high levels of satisfaction at all stages of the prostate patient's radiotherapy. By diversifying the format of information giving, the USTRs hope to further meet the information needs of patients.

IMPLICATIONS FOR PRACTICE

Validation of a prostate cancer radiotherapy pathway which employs USTRs and utilises a patient preparation seminar. This model could support the introduction of Specialist Therapeutic Radiographers in other Trusts and treatment sites.

National survey of fiducial marker insertion for prostate image guided radiotherapy

INTRODUCTION

In the United Kingdom fiducial marker IGRT is the second most common verification method employed in radical prostate radiotherapy yet little evidence exists to support centres introducing or developing this practice. We developed a survey to elicit current fiducial marker practices adopted in the UK, to recommend standardisation of practice.

METHODS

A 16 question survey was distributed across UK Radiotherapy centres via promotion at the British Uro-Oncology Group Conference, 2016. Included were questions relating to workforce planning, patient preparation, insertion procedure and verification methods. The survey was open from September 2016 to January 2017.

RESULTS

Results from 15 centres routinely inserting fiducial markers for prostate IGRT are presented. Eleven professional groups insert fiducial markers across the UK. Fourteen centres insert fiducial markers trans-rectally; one trans-perineally. Centres adopting a trans-rectal approach administer prophylactic ciprofloxacin as a single agent or combined with gentamicin or metronidazole; poor agreement between regimes presented. One centre has introduced targeted antibiotic prophylaxis. Five brands of fiducial markers are utilised nationally. Fourteen centres standardly insert three single fiducial markers, two common configurations emerged. Coupled fiducial markers are routinely implanted by one centre. All centres delay at least one week between fiducial marker insertion and planning CT; seven centres wait two weeks. The most common fiducial verification method is two-dimensional, paired kilo Voltage imaging.

CONCLUSION

Variation in fiducial marker practice across the UK is considerable. Standardisation is required to support centres and healthcare professionals developing this service. Seven recommendations, to unify practice, have been proposed based on survey results and literature.

Inter-rater reliability of distal ureteral diameter ratio compared to grade of VUR

INTRODUCTION AND OBJECTIVE

Management of vesicoureteral reflux (VUR) remains controversial, and reflux grade constitutes an important prognostic factor. Recent work has suggested that distal ureteral diameter ratio (UDR) is a predictive factor relative to clinical outcome independent of grade. Previous studies have noted significant inter-rater variability with grading of VUR. The present study compared inter-rater reliability of reflux grade and UDR in children with primary VUR.

STUDY DESIGN

Four pediatric urologists independently reviewed, in a blinded fashion, voiding cystourethrograms. For each renal unit, grade was assigned according to the standardized international scale. The UDR was calculated by dividing the largest ureteral diameter within the false pelvis by the distance between L1-L3 vertebral bodies. Correlation within each rater was determined using Pearson's correlation coefficient. Reliability of VUR grade and UDR were calculated using two-way ANOVA model inter-rater agreement.

RESULTS

Four independent raters reliably measured VUR grade (ICC = 0.87, 95% CI = 0.78-0.93) and UDR (ICC = 0.95, 95% CI = 0.92-0.97). While UDR and grade were equally reliable measures, UDR had a tighter confidence interval. For each rater, grade and UDR were well correlated (r = 0.73-0.84; P < 0.0001). For higher-grade reflux, grade was more variable than UDR (Summary Figure). Using empirical thresholds, the increased variability of grade compared with UDR may lead to significant differences in clinical decision-making among physicians (P = 0.022).

DISCUSSION

Known discordance with grading reflux emphasizes the need for a more objective VUR measurement, as clinicians and parents often opt for clinical intervention based on both clinical course and the likelihood of spontaneous resolution. While ICC for UDR and grade were not significantly different, the confidence intervals for grade were wider due to greater variability among grade measurements. This suggests that using UDR measurements may lead to more accurate characterization of VUR and ultimately more consistent clinical decision-making across providers.

CONCLUSIONS

Ureteral diameter ratio has good inter-rater reliability among pediatric urologists, with less clinically relevant variability than VUR grade. Ureteral diameter ratio is a more objective and reliable measure than grade, and may be more useful in clinical decision-making.

Utility of the distal ureteral diameter on VCUG for grading VUR

INTRODUCTION

For children with VUR the grade of vesicoureteral reflux (VUR) remains one of the most predictive factors relative to outcome. However, the subjective nature of the currently accepted international reflux grading system (IRGS) leads to inter-observer variation. The potential of a direct measurement of the distal ureter on the voiding cystourethrogram (VCUG) normalized to the L1-L3 vertebral body distance (ureteral diameter ratio - UDR) to augment the ability of IRGS to predict the ultimate clinical outcome has previously been reported in a group of 79 children.

OBJECTIVE

The goal of this current review was to expand the previous review and analysis in order to assess the predictive ability of the UDR with respect to earlier clinical outcome and to compare this ability to the grade of VUR while controlling for other variables.

STUDY DESIGN

This retrospective review of the VCUG of 157 children with primary VUR included 124 girls and 33 boys with a mean age of 2.7 years (7 days-13.5 years). In addition to the UDR, other variables that were analyzed included: age, gender, VUR grade, laterality, history of febrile urinary tract infection (UTI) or multiple UTIs prior to diagnosis, and bladder-bowel dysfunction (BBD). Cox regression analysis was utilized and a generalized logit model for 2-year outcome was also fitted to compare the effect of UDR and VUR grade using Wald Chi-squared analysis.

RESULTS

The 2-year outcome after the VCUG was defined as: persistent VUR (47%), spontaneous VUR resolution (15%), or operative intervention (38%). Reasons for operative intervention included: breakthrough UTI (1/3), decreased relative renal function associated with renal scarring (1/3), and failure to resolve, along with parental preference (1/3). Increasing UDR was significantly associated with increased grade and a decreased chance of spontaneous resolution. It was unlikely for a child with Grade 4, 3, or 2 VUR to have spontaneous resolution if their UDR was above 0.25, 0.3, or 0.35, respectively. In addition, higher grades of VUR, older age, and bilateral VUR were significantly associated with failure to spontaneously resolve VUR. As seen in Figure, children with grades 2 and 3 VUR less than 2 years of age had a better chance of spontaneous resolution with a larger UDR than children 2 years of age or older. When adjusting for age, grade, laterality and multiple UTIs as covariates, each unit increase of UDR of 0.1 was significantly associated with either persistent VUR (OR = 1.73, 95% CI = 1.02-2.95, P = 0.043) or the need for surgical intervention (OR = 2.40, 95% CI = 1.39-4.17, P = 0.002) compared to spontaneous resolution. When testing the effect of UDR and grade of reflux in the same model, UDR was noted to have a larger effect on predicting failure to spontaneously resolve VUR than grade (Wald Chi-Squared 13.6; P = 0.001 vs 3.62; P = 0.46, respectively).

DISCUSSION

The UDR is a readily available objective measurement on the VCUG that has demonstrated ability to enhance the International Reflux Grading System. Limitations of the current review include operative intervention in 12% of the children for failure to improve or resolve VUR. This surgical intervention inhibits determination of spontaneous resolution rates. The findings in this study reflect those in a series of children from a single institution and, therefore, may be impacted by clinical practice bias and geographic variations. Subsequent multi-institutional studies could further define the potential of UDR as either an independent or additive predictive factor for grading VUR that will further permit individualized patient management.

CONCLUSION

In this single institution series, UDR was highly correlated with VUR grade; however, UDR proved more predictive of spontaneous resolution, persistence, or operative intervention than grade.

Gonadotropin and ovarian hormone dynamics in luteal phase defects

Blood samples were obtained during early follicular, periovulatory, and luteal phases in four women with out-of-phase endometrial biopsy specimens and four normal controls. In the study cycle, follicular development was evaluated and a late luteal phase endometrial biopsy was performed in each subject. Area under the luteal phase progesterone curve positively correlated with degree of maturity of the endometrial biopsy. Peak serum estradiol, maximum follicular diameter, and both immunoactivity and bioactivity of the preovulatory luteinizing hormone and follicle-stimulating hormone surges were similar in the luteal phase defect cycles as compared with normal cycles. Likewise luteinizing hormone bioactivity in the luteal phase of the luteal phase defect cycles was similar to that of normals. These data show that the immunoactivity and bioactivity of periovulatory and luteal phase gonadotropins may be normal in luteal phase defect cycles.

Pain relief in hysterosalpingography. A comparison of analgesics

Hysterosalpingography provides important information in the evaluation of infertility but is generally considered an uncomfortable and painful procedure. We evaluated various analgesics for decreasing or eliminating the discomfort from this procedure. Two types of analgesia were required to give maximum pain relief during and after the examination in the 180 patients evaluated. The best results were achieved with a combination of naproxen sodium, 550 mg, given orally two hours before the examination, and 20% benzocaine, applied to the cervix.

The effect of aging on hypothalamic function in oophorectomized women

To detect age-related changes intrinsic to hypothalamic-pituitary function, we studied plasma gonadotropin levels in 12 oophorectomized women ages 27 to 64 years who were not undergoing hormone replacement therapy. Blood drawn from an indwelling catheter every 10 minutes for 5 hours was assayed for follicle-stimulating hormone, luteinizing hormone, estradiol, and prolactin concentrations. All estradiol levels were less than 20 pg/ml and prolactin values were normal. Mean gonadotropin concentrations, pulse frequency, and pulse amplitude were no different in women aged 27 to 49 years as compared with subjects 52 to 64 years old. When grouped according to gynecologic age (years since puberty) or years after oophorectomy, luteinizing hormone and follicle-stimulating hormone mean concentrations, mean pulse frequency, and mean pulse amplitude were comparable to those grouped according to chronologic age. On the basis of our findings, lack of response from postmenopausal ovaries to endogenous gonadotropin stimulation is a result of primary age-related change in the ovary, not in the hypothalamus.