8. FOLLOW UP
The aims for follow-up after treatment for UTUC are to comply with patient rehabilitation needs, to detect recurrent or new primary tumours within the urothelium, and to detect regional and distant metastases. Patient, tumour and treatment characteristics impact, when designing interval, length and modalities for follow-up in the individual patient. Bladder recurrence is not considered a distant recurrence. Unfortunately, the heterogeneity of available studies on disease-recurrence in UTUC is significant, and recommendations on follow-up have a low level of evidence at best.
After RNU for low-risk tumours, a negative cystoscopy at three months post-operatively, a subsequent cystoscopy 9 months later and yearly cystoscopies for 5 years based on follow-up data in low-risk Ta BC . Screening for metastases during follow-up is not mandatory, nor is CT urography mandatory in case of a tumour-free bladder due to a low risk of metachronous UTUC .
When RNU has been performed for high-risk tumours, stringent follow-up is mandatory to detect metachronous bladder tumours (probability increases over time ), local recurrence, and distant metastases. The risk of bladder recurrences and other-site recurrences decreases 4 years after RNU, suggesting that less vigorous annual cystoscopies and cross-sectional imaging including CT urographies thereafter may apply .
After kidney-sparing management for low-risk UTUC, and no upstaging or upgrading occured after the early second-look ureteroscopy after 6-8 weeks  or in the resection specimen after segmental ureteric resection, cystoscopy and CT-urography at 3 and 6 months, and then yearly for 5 years. The risk for bladder recurrences beyond 5 years is limited (6%) .
In patients treated with kidney-sparing for high-risk tumours, the indication (imperative vs. non-imperative) affects the surveillance regimen by the consequences of recurrent disease. Still, the ipsilateral UUT requires careful and long-term follow-up due to the high risk of disease recurrence [203,318,319] and progression following RNU, even beyond 5 years .
Surveillance regimens are based on cystoscopy and urinary cytology [15,315]. There are, however, several unanswered questions related to the optimal follow-up of patients treated for both low-risk and high-risk UTUC, of which some are:
- The added value of new urinary markers compared to cytology in voided urine samples .
- The effect of the Paris System on sensitivity and specificity of voided and selective urinary cytology during follow-up of UTUC, especially in high-risk tumours .
- If adjuvant upper tract instillations have been administered after endourologic kidney-sparing management, will that allow for less vigorous follow-up?
- The role of ureteroscopies of the ipsilateral upper urinary tract during follow-up after endourologic kidney-spring treatment vs. CT urography and voided urinary cytology.
Additionaly, it is not known how patients with Lynch syndrome, without and with UTUC, should be followed long-term given the inadequacy of surveillance based on urinalysis for nonvisible haematuria  and urine cytology , particularly in those individuals who are MSH2 mutation carriers  and those who already have developed a UTUC. Section 8.1 presents the summary of evidence and recommendations for follow-up of UTUC.
8.1. Summary of evidence and recommendations for the follow-up of UTUC
Summary of evidence
Follow-up is more frequent and more stringent in patients who have undergone kidney-sparing treatment compared to radical nephroureterectomy.
After radical nephroureterectomy
Perform cystoscopy at three months. If negative, perform subsequent cystoscopy 9 months later and then yearly, for 5 years.
Perform cystoscopy and urinary cytology at 3 months. If negative, repeat subsequent cystoscopy and cytology every 3 months for a period of 2 years, and every 6 months thereafter until 5 years, and then yearly.
Perform computed tomography (CT) urography and chest CT every 6 months for 2 years, and then yearly.
After kidney-sparing management
Perform cystoscopy and CT urography at 3 and 6 months, and then yearly for 5 years.
Perform ureteroscopy (URS) at 3 months if no second-look ureteroscopy was performed.
Perform URS and urinary cytology in situ at 3 and 6 months.