Optimization of multimodal treatment protocols led to an increase in OS rates for high risk BP-RMS to more than 80% (Mandeville 2019; Saltzman and Cost 2018). Neoadjuvant chemotherapy is the backbone of all therapeutic strategies. A crucial aspect of multimodal treatment is the type of RT. Focusing on the potential toxicities of radiotherapy (bladder fibrosis, bowel injury, pelvic bone deformities, hypogonadism), attempts to reduce the dose to surrounding tissues are important (Cotter et al. 2011). Based on the favorable results of BT in vulval/vaginal RMS since the early 1970s in France (Flamant et al. 1990), a first report proved the advantages of this technique in combination with BPS in patients with BP-RMS (Martelli et al. 2009). The main advantage of BT is reduced irradiated volumes with a corresponding lower risk of late toxicity (Naghavi et al. 2017). Since then it has been generally accepted that BT, as well as proton therapy, is superior to photon radiotherapy in terms of
Table 3
Review of oncological and urological outcome. EP endoscopic polypectomy, ERT external radiotherapy, HDR high-dose-rate; LDR low-dose-rate; PDR pulse-dose-rate; RT Radiotherapy, PB proton beam, *7 pts. aged >6 years were evaluated concerning continence, 14 pts. aged > 4 were evaluated concerning erections **Dribbling, incontinence, hydronephrosis, enuresis before the age of 10 years considered “normal”; ***of 11 pts. > 6 years; **** of 18 pts. > 6 years, ‡ pubertal / adolescent pts., ‡‡ normal erections observed by parents in 5 of 20 pts.
Study
|
No (male),
Urological evaluated
|
Surgery, No
|
Radiation, No (dosage)
|
Median follow-up
[months]
|
Median age at FU
|
Survival and relapse
|
Normal voiding function
|
Normal
Erectile function/
Hormonal replacement
|
Outcome measurements, No
|
Recent Study
|
40 (36), 37
|
BPS, 38
|
HDR-BT, 32
(30-36 Gy)
|
37
|
6 years
|
96% OS
70% EFS
9 relapses
1 death
|
83% ****
|
92%
2.7%
|
Bladder capacity, 37
Residual urinary volume, 30
Uroflowmetry, 26
Urodynamics, 21
|
Stenman
2022
|
10 (7), 10
|
BPS, 5
|
HDR-BT, 10
(39-42 Gy)
|
62
|
No data
|
100% OS
90% EFS
|
100%
|
100%
4.3%
|
Bladder capacity, 8
Uroflowmetry, 8
Residual urinary volume, 8
Urodynamics, 1
Questionnaire, 8
|
Lobo 2022
|
13 (10), 13
|
BPS, 2
EP, 4
|
HDR-BT, 13
(27.5 Gy)
|
42
|
6 years
|
No deaths
No relapse
|
62%
|
No data
|
Bladder capacity, 13
Uroflowmetry, 13
Urodynamics, 2
|
Indelicato
2019
|
31
|
BPS, 8
|
PB, 31,
(36-50.4 Gy)
|
48
|
No data
|
84% OS
80% EFS
|
89%
|
No data
|
Anamnestic, 31
|
Chargari 2017
|
32 (26), 7/14*
|
BPS, 29
|
LDR/PDR-BT, 32
(60 Gy)
|
20
|
>6
|
91% OS
84% EFS
|
71%
|
100%
|
Anamnestic, 7; 14*
|
Frees 2016
|
13 (13), 13
|
BPS, 13
|
RT or BT, 3
(no data)
|
152
|
20 year
|
No data
|
No data
|
24%
|
Questionnaire, 13
|
Martelli 2016
|
27 (27), 22
|
BPS, 27
|
LDR-BT, 27
(60 Gy (20 Gy + 45 Gy ERT))
|
120
|
13 years
|
3 deaths
|
55%
|
100% ‡
|
Urodynamics, 11
Questionnaire, 22
|
Martelli
2009
|
26 (26), 22
|
BPS, 26
|
LDR-BT, 26
(60 Gy)
|
48
|
|
2 deaths
|
82% **
|
100% ‡
25% ‡‡
|
Anamnestic, 22
Urodynamics, 1
|
Arndt
2004
|
55
|
BPS, 55
|
XRT, 55,
41-59.4 Gy
|
No data
|
No data
|
82% OS
77% EFS
|
65% ***
|
No data
|
Urodynamics, 1
Questionnaires, 23
|
doses to the surrounding tissues (Heinzelmann et al. 2011). The oncological outcome is convincing; in a large prospective cohort, the combination of BPS with BT facilitated a 5y-EFS and -OS rate of 84%, respectively 91% (Chargari et al. 2017; Schmidt et al. 2020; Zakem et al. 2022). In the recent update of our findings, we had to add one relapse-related death. Because of the special circumstances with initial denial of local therapy, it can be assumed that this death could have been avoided. Simultaneously, this case emphasizes the importance of timely local therapy. Other studies with longer postoperative follow-up times but smaller study cohorts reported 100% EFS rates after BT in BP-RMS patients (Lobo et al. 2022; Stenman et al. 2022).
A direct comparison of oncological outcomes is compromised, with either no information about the IRS stage being given (Lobo et al. 2022) or information about tumor diameters being incomplete (Stenman et al. 2022). This emphasizes the importance of accurately describing key oncologic data, even when the focus is on functional outcomes. Only one study provided a full description of oncological details, with a group size comparable to our cohort (Martelli et al. 2016) and an oncological outcome comparable to ours. In contrast to our approach, these authors used LDR-BT.
The most common complication in our patients was postoperative leakage of the reconstructed urethra or bladder, reflecting the results of other groups. Three cases of radiation urethritis in our group found no corresponding cases in follow-up studies of other groups, but urethral stricture as a late complication has been described (Martelli et al. 2016).
In the adult section, urinary incontinence rates vary from 0-19% (Leapman et al. 2016). In pediatric patients, objective urological outcomes are more difficult to gather due to age; micturition protocols, voiding frequencies or measurements of maximum voided volumes are
difficult to obtain in the diaper age. Furthermore, families, surgeons and oncologists, have primarily focused on oncological outcomes. Additionally, very often, only short-term follow-up is performed by the centers of local therapy, and many patients are further followed-up by their oncologists close to home. For this reason, some authors refer to questionnaires to assess the results after longer follow-up periods (Arndt et al. 2004; Frees et al. 2016; Stenman et al. 2022), or even only describe anamnestic findings (Chargari et al. 2017; Indelicato et al. 2020) (table 3).
As during oncological follow-up, regular MRI in narcosis is performed, BC can be easily calculated in a relaxed child noninvasively. With this method, it was possible to objectify BC related to EBCA and correlate it to the postoperative period. Our data showed an increase in bladder capacity during the first 9 months after BPS+BT and a slight decrease during the following 15 months. At a median follow-up of 2.5 years and a median age of 5.8 years, our patients had a bladder capacity of 74% of EBCA without a significant difference between the groups. Only one article described BC after BT, these authors found a median BC of 75% EBCA at a median age of 6 years in 2 cases after partial cystectomy with BT compared to 96% EBCA after endoscopic polypectomy with BT (Lobo et al. 2022).
Furthermore, the assessment of compliance in this age group, if urodynamic tests are performed at all, is limited by the lack of normal values. A reduced compliance value denotes an increase in bladder wall stiffness and is a risk factor for upper tract damage. In our cohort, compliance values were mostly well below 10 ml/cmH2O. However, with regard to EBACom, the majority of the measured values were within the normal range and improvement due to anticholinergic drugs could be made visible. In other studies, urodynamic testing was rarely performed and urodynamic findings were not provided in detail (Arndt et al. 2004; Lobo et al. 2022; Martelli et al. 2009; Stenman et al. 2022), except in one study (Martelli et al. 2016).
In adults after BT without ED before therapy, ED is described in up to 21% of adults after BT. There was no significant difference between HDR- and LDR-BT in long-time sequelae in the elderly (Johansson et al. 2021). In the early follow-up of pediatric patients, EF can only be obtained by parental observation, which entails a certain bias. Interestingly, a study of adult long-term survivors of pediatric BP-RMS described ED in 100% after radical surgery with adjuvant radio-/ or brachytherapy and in 70% after radical surgery only. This is the only study on adults with questionnaires but also deals with low number of patients who were treated with surgery and radio-/brachytherapy (Frees et al. 2016). Other studies reported approximately 100% normal EF in low numbers of adolescent or adult patients, controversially (Chargari et al. 2017; Martelli et al. 2016; Martelli et al. 2009; Stenman et al. 2022). With the awareness of possible later impairment of EF, we learned that well-informed parents were able to observe the EF of their sons fairly well. However, this may only be a hint of later outcomes in this respect. In the herein reported patient cohort, three patients had ED, representing 10% of the BPS+BT group. Testosterone deficiency has been reported in adults with prostate cancer after radiation therapy even without androgen deprivation therapy. In adult patients after permanent interstitial BT for localized prostate cancer, initially decreased testosterone levels recovered at 18 months after BT (Taniguchi et al. 2019). Cases of hypogonadism in adolescents after BT in childhood have been described rarely (Stenman et al. 2022). In our cohort, one boy needs hormonal replacement therapy. As most of our patients were still in a prepubertal age, further follow‑up studies will be conducted.
In summary, this recent study is the first with a detailed analysis of functional urological outcomes according to age groups after BPS and HDR-BT and the largest series with available urodynamic studies. The reported rates of normal bladder function after multimodal bladder preserving therapies is differing in literature from 55% to 100% (Arndt et al. 2004; Lobo et al. 2022; Chargari et al. 2017; Frees et al. 2016; Indelicato et al. 2020; Martelli et al. 2016; Martelli et al. 2009; Stenman et al. 2022). Our cohort with 83% normal bladder function is well in range with these. Many studies, including small patient cohorts (Lobo et al. 2022), are restricted by their ambiguous definition of normal bladder function (Arndt et al. 2004) and do not always describe surgical details since the primary focus is still on the oncological outcome. Current research also suggests, that problems of the lower urinary tract and/or ED may increase with a longer median follow-up (Frees et al. 2016; Castagnetti, Herbst, and Esposito 2019). Our study included 40 patients with BPS, 32 of whom received additional BT. Similar to other studies, our observation period was still too short to allow truly representative conclusions to be drawn, as more than half of the children were younger than 6 years at their last follow-up. Another limitation of our study is its retrospective nature.
In conclusion, short-term observations of urologic outcomes in patients with BP-RMS are encouraging, and long-term analyses are desirable. The urological outcome should be monitored as closely as the oncologic outcome to reflect a realistic overall impression in patients with BP-RMS.