Membranous urethral length measurement on preoperative MRI to predict incontinence after radical prostatectomy: a literature review towards a proposal for measurement standardization

OBJECTIVES

To investigate the membranous urethral length (MUL) measurement and its interobserver agreement, and propose literature-based recommendations to standardize MUL measurement for increasing interobserver agreement. MUL measurements based on prostate MRI scans, for urinary incontinence risk assessment before radical prostatectomy (RP), may influence treatment decision-making in men with localised prostate cancer. Before implementation in clinical practise, MRI-based MUL measurements need standardization to improve observer agreement.

METHODS

Online libraries were searched up to August 5, 2022, on MUL measurements. Two reviewers performed article selection and critical appraisal. Papers reporting on preoperative MUL measurements and urinary continence correlation were selected. Extracted information included measuring procedures, MRI sequences, population mean/median values, and observer agreement.

RESULTS

Fifty papers were included. Studies that specified the MRI sequence used T2-weighted images and used either coronal images (n = 13), sagittal images (n = 18), or both (n = 12) for MUL measurements. 'Prostatic apex' was the most common description of the proximal membranous urethra landmark and 'level/entry of the urethra into the penile bulb' was the most common description of the distal landmark. Population mean (median) MUL value range was 10.4-17.1 mm (7.3-17.3 mm), suggesting either population or measurement differences. Detailed measurement technique descriptions for reproducibility were lacking. Recommendations on MRI-based MUL measurement were formulated by using anatomical landmarks and detailed descriptions and illustrations.

CONCLUSIONS

In order to improve on measurement variability, a literature-based measuring method of the MUL was proposed, supported by several illustrative case studies, in an attempt to standardize MRI-based MUL measurements for appropriate urinary incontinence risk preoperatively.

CLINICAL RELEVANCE STATEMENT

Implementation of MUL measurements into clinical practise for personalized post-prostatectomy continence prediction is hampered by lack of standardization and suboptimal interobserver agreement. Our proposed standardized MUL measurement aims to facilitate standardization and to improve the interobserver agreement.

KEY POINTS

• Variable approaches for membranous urethral length measurement are being used, without detailed description and with substantial differences in length of the membranous urethra, hampering standardization. • Limited interobserver agreement for membranous urethral length measurement was observed in several studies, while preoperative incontinence risk assessment necessitates high interobserver agreement. • Literature-based recommendations are proposed to standardize MRI-based membranous urethral length measurement for increasing interobserver agreement and improving preoperative incontinence risk assessment, using anatomical landmarks on sagittal T2-weighted images.

Patient-reported outcome measures compared to clinician reported outcomes regarding incontinence and erectile dysfunction in localized prostate carcinoma after robot assisted radical prostatectomy: Impact on management

PURPOSE/ BACKGROUND

Patient-reported outcome measures (PROMs) are widely used after robot assisted radical prostatectomy (RARP) in order to evaluate the impact/burden of the treatment. The most bothersome side effects of RARP are urine incontinence (UI) and erectile dysfunction (ED). During the follow up consultations, clinicians report these side effects in interviewing patients. Our study examined the discrepancy between the PROMs and clinician report outcomes (CROs) and hypothesized that the disagreement could have an impact on the management of UI and ED.

METHODS

Up to 1 year after RARP, UI and ED recovery of 312 men with localized and locally advanced prostate cancer were assessed using the International Consultation Incontinence Questionnaire Short-Form (ICIQ-SF) and the International Index of Erectile Function (IIEF-EF) and CROs by interview. Discrepancies between PROs and CROs were studied in light of treatment offered and management.

RESULTS

The ICIQ-SF Score matched with CROs in all sum score categories except in ICIQ sum score 6 to 12; here the UI was underreported by clinicians in 58% and 59% of patients at 8 and 12 months (P < 0.001). Furthermore, at 8 and 12 months postoperatively, clinicians underreported UI in 29% and 23% of patients with ICIQ score 13-18 (P < 0.001). The clinician significantly over-reported the recovery of erectile function ("normal erection") (P < 0.001), especially in men with IIEF-EF sum score 6 to 16. Independently of ICIQ-SF/IIEF-EF scores, discrepancy between PROs and CROs did not affect rate of health care offered to patients.

CONCLUSIONS

This is to our knowledge the first study that compared the PROs with clinician reported functional outcomes and the impact of discrepancies on the management of side effects of RARP in prostate cancer. Observed discrepancies between the PROs and CROs did not affect offered management and counseling of UI and ED.

Identifying Patients in Whom the Follow-Up Scheme after Robot-Assisted Radical Prostatectomy Could Be Optimized in the First Year after Surgery: Reducing Healthcare Burden

Background: The currently advised follow-up scheme of PSA testing after robot-assisted radical prostatectomy (RARP) is strict and might pose a burden to our healthcare system. We aimed to optimize the 1-year follow-up scheme for patients who undergo RARP. Methods: All patients with histologically-proven prostate cancer (PCa) who underwent RARP between 2018 and August 2022 in the Prostate Cancer Network in the Netherlands were retrospectively evaluated. We excluded patients who underwent salvage RARP and patients who had <1 year of PSA follow-up. Postoperative PSA values were collected. Biochemical persistence (BCP) was defined as PSA level >0.10 ng/mL at 0–4 months after RARP, whereas biochemical recurrence (BCR) was defined as PSA level >0.2 ng/mL at any time point after RARP. We aimed to identify a group of patients who had a very low risk of BCR at different time points after surgery. Results: Of all 1155 patients, BCP was observed in 151 (13%), of whom 79 (6.8%) had PSA ≥ 0.2 ng/mL. BCR further developed in 51 (4.7%) and 37 (3.4%) patients at 5–8 and 9–12 months after RARP, respectively. In 12 patients, BCR was found at 5–8 months after RARP in the absence of BCP. These patients represented 1.2% (12/1004) of the entire group. In other words, 98.8% (992/1004) of patients who had an unmeasurable PSA level at 0–4 months after RARP also had an unmeasurable PSA level 5–8 months after surgery. Limitations are the retrospective design and incomplete follow-up. Conclusions: Patients with an unmeasurable PSA level at 3–4 months after RARP may not need to be retested until 12 months of follow-up, as almost 100% of patients will not have the biochemically recurrent disease at 5–8 months of follow-up. This will reduce PSA testing substantially at the cost of hardly any missed patients with recurrent disease.

Communication, perception, and use of personalized side-effect risks in prostate cancer treatment-decision making: An observational and interview study

OBJECTIVE

We investigated how healthcare professionals (HPs) communicate personalized risks of treatment side-effects to patients with localized prostate cancer during consultations, and explored how these patients perceive and use such risks during treatment decision-making.

METHODS

Patient consultations with nurse practitioners and urologists discussing personalized risks of urinary incontinence after prostatectomy were audiotaped, transcribed, and coded. Patients (n = 27) were then interviewed to explore their perceptions and use of personalized side-effect risks.

RESULTS

HPs explained personalized risks by discussing risk factors, which was appreciated and recalled by patients. Personalized risks were typically communicated both numerically and verbally (70%). When using numbers, HPs always used percentages, but rarely used natural frequencies (14%). Uncertainty was disclosed in only 34% of consultations. One-third of patients used personalized risks in their treatment decision-making by either switching to another treatment or sticking to their initial preference.

CONCLUSIONS

Patients value and use personalized side-effect risks during treatment decision-making. Clearly explaining the relationship between risk factors and personalized risk estimates may help patients understand and recall those. Practice implications HPs should not only give patients specific and precise numerical risk information, but should also put effort in explaining how the personalized side-effect risks are determined.

Functional outcomes rather than complications predict poor health-related quality of life at 6 months after robot-assisted radical prostatectomy

The objective is to evaluate the effect of robot-assisted radical prostatectomy (RARP)-related postoperative complications on the 6-month postoperative health-related quality of life (HRQoL). A total of 1008 patients underwent a RARP with or without pelvic lymph node dissection (PLND) between 2012 and 2020 and were invited to complete questionnaires about HRQoL and functional outcomes (urinary incontinence (UI), erectile dysfunction (ED) and urinary complaints (UC)) before and 6 months after RARP. Patient characteristics and postoperative complications up to 90 days after surgery were prospectively recorded. Associations between complications and HRQoL/functional outcomes were assessed by multivariate linear regression analyses. In total, 528 patients (52.4%) were included in the analyses. Complications occurred in 165/528 (31.3%) patients, of which 30/165 (18.2%) had a Clavien-Dindo ≥ III complication. In multivariate regression analyses, postoperative complications were not significantly associated with postoperative HRQoL, UI and ED (p = 0.73, p = 0.72 and p = 0.95, respectively), but were significantly associated with a minor increase in UC (β = 1.7, p < 0.001). More specifically, infectious and urological complications were significantly associated with an increase in UC (β = 1.9, p < 0.001 and β = 0.9, p = 0.004, respectively). The presence of UTI, in particular, was significantly associated with this minor increase (β = 1.5, p = 0.002). Functional outcomes were all significantly associated with the HRQoL at 6 months postoperatively. No significant associations were found between postoperative complications and HRQoL at 6 months after RARP. However, worse functional outcomes were associated with a worse HRQoL at 6 months postoperatively. In addition, postoperative infectious and urological complications were significantly associated with a minor increase in UC.

Individual risk prediction of urinary incontinence after prostatectomy and impact on treatment choice in patients with localized prostate cancer

AIMS

Individualized information about the risk of incontinence after prostatectomy could help patients in shared decision-making.

METHODS

We compared a historical control cohort (n = 254; between June 2016 and 2017) that received standardized information about the risk of incontinence after robot-assisted radical prostatectomy (RARP) with a prospective patient cohort (n = 254; between June 2017 and May 2018) that received individualized information of the chance of recovery of incontinence within 6 months postoperatively based on the continence prediction tool (CPRED). We measured switch in treatment choice, health-related quality of life (QoL) in both cohorts and the accuracy of the CPRED tool.

RESULTS

Patients in the individualized information group with RARP as initial preference switched more often to another treatment than patients who received standardized information (16% vs. 5%; p = 0.001). Patients in the individualized information group with a high risk of incontinence and with RARP as initial preference switched more often to other treatments than patients in intermediate/low risk of incontinence (35% vs. 9.8%; p = 0.001). Patients with a low risk of incontinence choosing RARP after individualized information were less likely to use more than one diaper a day at any time postoperative (p = 0.001) compared to men with an intermediate/high incontinence risk. Overall QoL was worse in patients with incontinence than patients with continence 6 and 12 months after RARP (respectively; p < 0.0001 and p = 0.007).

CONCLUSION

Personalized information about the risk of incontinence after RARP makes more patients reconsidering their initial treatment preference. The CPRED correlated strongly with continence outcome after RARP and is a useful tool for shared decision-making.

The role of routine follow-up visits of prostate cancer survivors in addressing supportive care and information needs: a qualitative observational study

PURPOSE

To understand the role of routine follow-up visits in addressing prostate cancer survivors' supportive care and information needs.

METHODS

We audio-recorded follow-up visits of 32 prostate cancer survivors. Follow-up visits were analyzed according to the Verona Network of Sequence Analysis. We categorized survivors' cues, concerns, and questions into five supportive care domains and divided the responses by the healthcare professionals into providing versus reducing space that is to determine whether or not the response invites the patient to talk more about the expressed cue or concern.

RESULTS

Prostate cancer survivors mostly expressed cues, concerns, and questions (in the health system and information domain) about test results, potential impotence treatment, follow-up appointments, and (their) cancer treatment during follow-up visits. Survivors also expressed urinary complaints (physical and daily living domain) and worry about the recurrence of prostate cancer (psychological domain). Healthcare professionals were two times more likely to provide space on cues and concerns related to the physical and daily living domain than to psychological related issues.

CONCLUSION

Follow-up visits can serve to address prostate cancer survivors' supportive care and information needs, especially on the health system, information, and physical and daily living domain. Survivors also expressed problems in the psychological domain, although healthcare professionals scarcely provided space to these issues. We would like to encourage clinicians to use these results to personalize follow-up care. Also, these data can be used to develop tailored (eHealth) interventions to address supportive care and information needs and to develop new models of survivorship care delivery.

Sexual Satisfaction in Men Suffering From Erectile Dysfunction After Robot-Assisted Radical Prostatectomy for Prostate Cancer: An Observational Study

BACKGROUND

Preservation of erectile function is an important postoperative quality of life concern for patients after robot-assisted radical prostatectomy (RARP) for prostate cancer. Although erectile function may recover, many men continue to suffer from erectile dysfunction (ED).

AIM

This study aims to determine whether satisfaction with sexual life improves in patients with ED after RARP and which factors are associated with satisfaction during follow-up.

METHODS

A review was carried out of a prospectively maintained database of patients with prostate cancer who underwent a RARP between 2006 and 2019. The "International Index of Erectile Function" questionnaire was used to describe ED (range 5-25), overall satisfaction with sexual life and sexual desire (range for both: 2-10). Patients with ED due to RARP were compared with those without ED after RARP. Mixed effect model was used to test differences in satisfaction over time. Mann-Whitney U tests and multiple logistic regression were used to assess factors associated with being satisfied at 24 and 36 months.

OUTCOMES

The main outcomes of this study are the overall satisfaction with sexual life score over time and factors which influence sexual satisfaction.

RESULTS

Data of 2808 patients were reviewed. Patients whose erectile function was not known (n = 643) or who had ED at the baseline (n = 1281) were excluded. About 884 patients were included for analysis. They had an overall satisfaction score of 8.4. Patients with ED due to RARP had mean overall satisfaction scores of 4.8, 4.8, 4.9, and 4.6 at 6 mo, 12 mo, 24 mo, and 36 mo. These scores were significantly lower than those of patients without ED at every time point. In multiple regression analysis, higher overall satisfaction score at the baseline and higher sexual desire at 24 and 36 months' follow-up were associated with satisfaction with sexual life at 24 and 36 months' follow-up. No association was found for erectile function.

CLINICAL IMPLICATIONS

Interventions focusing on adjustment to the changes in sexual functioning might improve sexual satisfaction; especially for those men who continue to suffer from ED.

STRENGTHS & LIMITATIONS

Strengths of this study are the large number of patients, time of follow-up, and use of multiple validated questionnaires. Our results must be interpreted within the limits of retrospectively collected, observational data.

CONCLUSION

Satisfaction with sexual life in men with ED due to RARP may take a long time to improve. One could counsel patients that sexual satisfaction is based on individual baseline sexual satisfaction and the return of sexual desire after RARP. Albers LF, Tillier CN, van Muilekom HAM, et al. Sexual Satisfaction in Men Suffering From Erectile Dysfunction After Robot-Assisted Radical Prostatectomy for Prostate Cancer: An Observational Study. J Sex Med 2021;18:339-346.

Patient-reported Outcomes Following Treatment of Localised Prostate Cancer and Their Association with Regret About Treatment Choices

BACKGROUND

Well-documented reports of patients' experiences with different treatments are important for helping localised prostate cancer (LPC) patients choose among the available treatment options.

OBJECTIVE

To document differences in patient-reported outcomes (PROs) following radical prostatectomy (RP), external beam radiotherapy (EBRT), brachytherapy (BT), and active surveillance (AS), and to evaluate how these PROs and other factors are associated with treatment decision regret.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, observational, multicentre study of men diagnosed with LPC (stage cT1-2) during 2014-2016.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Patients completed validated PRO measures (Quality of Life Questionnaire Core 30 [QLQ-C30], Quality of Life Questionnaire prostate cancer-specific module [QLQ-PR25], Decision Regret Scale, and the Memorial Anxiety Scale for Prostate Cancer) before treatment and at 3, 6, and 12mo after treatment. Mixed-effect models were used to describe different PRO patterns.

RESULTS AND LIMITATIONS

The analytic cohort included 434 men (AS=32%; RP=45%; EBRT=12%; BT=10%). Follow-up response rates were above 90%. At 1-yr follow-up, (1) men who had received RP reported significantly (p<0.01) more urinary incontinence, sexual dysfunction, hormonal/masculinity-related symptoms, and less emotional distress; (2) those having received EBRT reported more sexual dysfunction, hormonal/masculinity-related symptoms, and physical distress; and (3) those having received BT reported more urinary obstruction and irritation symptoms, compared with patients under AS. Irrespective of the treatment modality, 23% of the patients reported clinically relevant treatment regret (99% confidence interval, 17-28%). Multivariate correlates of decision regret were hormonal/masculinity-related symptoms, educational level, and positive surgical margins.

CONCLUSIONS

Post-treatment physical and psychosocial functioning was significantly associated with specific treatment modalities and pretreatment functioning. Regret was relatively frequently reported by patients who experienced unwanted physical, psychosocial, and oncological outcomes. Greater efforts should be made to understand whether carefully educating patients about the possible consequences and effectiveness of treatments may help limit the feeling of treatment regret.

PATIENT SUMMARY

In men with localised prostate cancer, regret about the treatment choice was more common among those who experienced more treatment-related symptoms during the year after treatment.

[The accuracy of patients' perceptions of the risks associated with localised prostate cancer treatments]

OBJECTIVE

To assess the accuracy of patients' perceptions of the risks associated with localised prostate cancer treatments (radical prostatectomy [RP], radiotherapy [RT], and active surveillance [AS]), and to identify correlates of misperceptions.

PATIENTS AND METHODS

We used baseline data (questionnaires completed after treatment information was provided but before treatment) of 426 patients with newly diagnosed localised prostate cancer who participated (87% response rate) in a prospective, longitudinal, multicentre study. Patients' pretreatment perceptions of differences in adverse outcomes of treatments were compared to those based on the literature. We used univariate and multivariate linear regression to identify correlates of misperceptions.

RESULTS

About two-thirds (68%, n = 211) of the patients did not understand that the risk of disease recurrence is comparable between RP and RT. More than half of the patients did not comprehend that RP patients are at greater risk of urinary incontinence (65%, n = 202) and erectile dysfunction (61%, n = 190), and less at risk of bowel problems (53%, n = 211) compared to RT patients. Many patients overestimated the risk of requiring definitive treatment following AS (45%, n = 157) and did not understand that mortality rates following AS, RP, and RT are comparable (80%, n = 333). Consulting a radiotherapist or a clinical nurse specialist was positively associated with, and emotional distress was negatively associated with, better understanding of the risks (P < 0.05), although effect sizes were small.

CONCLUSION

Prior to choosing treatment, most patients with prostate cancer poorly understood the differences in treatment risks. Greater efforts should be made to better understand why these misperceptions occur and, most importantly, how they can be corrected.

Prevalence and correlates of mental health problems in prostate cancer survivors: A case-control study comparing survivors with general population peers

OBJECTIVE

The purpose of this study was to identify factors associated with mental health (MH) problems in prostate cancer (PC) survivors. Toward this end, we evaluated (1) differences in the prevalence of MH problems between PC survivors and age-matched men from the general population (GenPop) and (2) correlates of MH in PC survivors and the GenPop.

METHODS AND MATERIALS

In this observational case-control study, we age-matched PC survivors (n = 644, alive≥5y after diagnosis of a stage I-IV carcinoma) recruited from Dutch community hospitals (Patient Reported Outcomes Following Initial treatment and Long-term Evaluation of Survivorship registry) with GenPop peers (n = 644) selected from a population-based sample recruited in general practices (NIVEL). MH was operationalized using the 5-item Mental Health Inventory of the Short Form Health Survey (SF-36). Potential correlates of MH included sociodemographic characteristics, health-related quality of life scores, and clinical characteristics (PC survivors only). We used analysis of (co)variance and chi-square tests to address the 2 research questions.

RESULTS

We observed clinically relevant MH symptoms in 14% of the PC survivors and 6% of the GenPop controls (P<0.01, odds ratio = 2.45 [1.66-3.62]). The most important correlates of lower MH scores in the PC survivors were being widowed, a lower educational level, lower general health perceptions, more bodily pain and urinary bother, and less sexual satisfaction. The most important correlates of lower MH scores in the GenPop were as follows: lower general health perceptions, more role limitations because of physical problems, and more bodily pain.

CONCLUSIONS

Our results indicate that long-term PC survivors have poorer MH, as assessed by the 5-item Mental Health Inventory questionnaire, than men of a comparable age from the GenPop without a history of PC. Attention to potentially modifiable factors associated with MH problems in PC survivors, such as urinary function and its related bother, bodily pain, and sexual satisfaction, may help to prevent or limit MH problems in this survivor population.

The Effect of Salvage Radiotherapy and its Timing on the Health-related Quality of Life of Prostate Cancer Patients

BACKGROUND

The impact of salvage radiotherapy (SRT) and its timing on health-related quality of life (HRQoL) in prostate cancer patients is still unclear.

OBJECTIVE

To compare the HRQoL of patients who underwent SRT with that of patients who underwent radical prostatectomy (RP) only and to investigate whether SRT timing is associated with HRQoL.

DESIGN, SETTING, AND PARTICIPANTS

All SRT patients (n=241) and all RP-only patients (n=1005) were selected from a prospective database (2004-2015). The database contained HRQoL and prostate problem assessments up to 2 yr after last treatment.

OUTCOME MEASUREMENT AND STATISTICAL ANALYSIS

Mixed effects growth modelling adjusting for significant differences in patient characteristics and baseline HRQoL was used to analyze the association between: (1) "treatment" (RP-only vs SRT) and (2) "timing of SRT" with changes in HRQoL.

RESULTS AND LIMITATIONS

SRT patients showed significantly (p<0.05) poorer recovery from urinary, bowel, and erectile function after their last treatment (clinically meaningful difference for urinary and erectile function). Patients with a longer interval (≥ 7 mo) between RP and SRT reported significantly better sexual satisfaction after SRT (p=0.02), and a better urinary function recovery (p=0.03). Limitations of the study include the nonrandom design and the variability in timing of HRQoL measurements.

CONCLUSIONS

Up to 2 yr after treatment, SRT patients reported poorer HRQoL in several HRQoL domains compared with RP-only patients, but not in overall HRQoL. Delaying the start of SRT after RP may limit the incidence and duration of urinary and sexual problems. Nevertheless, decisions regarding SRT timing should also be based on the potential benefits in disease recurrence.

PATIENT SUMMARY

Patients who receive radiotherapy after surgery may experience poorer urinary, bowel, and erectile function compared with patients who undergo surgery only. Although more research is needed, delaying radiotherapy seems to limit its impact on urinary and sexual functioning.

Symptoms from treatment with sunitinib or sorafenib: a multicenter explorative cohort study to explore the influence of patient-reported outcomes on therapy decisions

PURPOSE

Optimal long-lasting treatment with sunitinib and sorafenib is limited by dose modifications (DMs) due to adverse events (AEs). These AEs may be underrecognized and their influence on health-related quality of life (HRQL) underestimated. Improved insight into the relationship between AEs and therapy decisions is needed. To improve decision making around managing symptoms and reduce DMs, this study was set up to explore the influence of patient-reported symptoms on therapy decisions.

METHODS

In this multicenter cohort study, patient characteristics, reasons for and different forms of used dose modifications, and AEs were prospectively obtained from cancer patients on sunitinib/sorafenib treatment. Used instruments to get insight into AEs were the patient-scored Utrecht Symptom Diary (USD) and the professional-scored Common Terminology Criteria for AEs version 3.0.

RESULTS

Median total treatment duration in 42 patients was 16 weeks. Median time till dose modification was 10 weeks. DMs occurred mostly due to multiple mild AEs. By using the USD, a higher prevalence of most AEs was found compared to the literature. Sixty percent of the patients experienced a decreased HRQL due to multiple AEs.

CONCLUSIONS

Because severe AEs due to sunitinib/sorafenib treatment seldom occur, it is more important to focus on treating and preventing multiple mild AEs with higher impact on HRQL, when trying to avoid dose modifications. Using patient self-reported measurement methods helps to early recognize symptoms and to differentiate among symptom intensities. This systematic approach might help to achieve the optimal dosing, which might improve PFS and OS.

Predictive factors for severe toxicity of sunitinib in unselected patients with advanced renal cell cancer

Sunitinib has been registered for the treatment of advanced renal cell cancer (RCC). As patient inclusion was highly selective in previous studies, experience with sunitinib in general oncological practice remains to be reported. We determined the efficacy and safety of sunitinib in patients with advanced RCC included in an expanded access programme. ECOG performance status >1, histology other than clear cell and presence of brain metastases were no exclusion criteria. Eighty-two patients were treated: 23% reached a partial response, 50% had stable disease, 20% progressed and six patients were not evaluable. Median progression-free survival (PFS) was 9 months and median overall survival (OS) was 15 months. Importantly, 47 patients (57%) needed a dose reduction, 35 (43%) because of treatment-related adverse events, 10 (12%) because of continuous dosing, and two because of both. Stomatitis, fatigue, hand-foot syndrome and a combination of grade 1-2 adverse events were the most frequent reasons for dose reduction. In 40 patients (49%), there was severe toxicity, defined as dose reduction or permanent discontinuation, which was highly correlated with low body surface area, high age and female gender. On the basis of age and gender, a model was developed that could predict the probability of severe toxicity.