Background
International multicenter prospective study (IELSG-10). 53 patients with primary testicular diffuse large B-cell lymphoma (PT-DLBCL) from 8 European countries. Tested a standardized treatment protocol: R-CHOP × 6 + intrathecal MTX × 4 + contralateral testicular RT (30 Gy) + CNS prophylaxis. PT-DLBCL is characterized by high relapse rate in the contralateral testis and CNS.
Interventions and follow up
Arm A: R-CHOP × 6 + intrathecal MTX × 4 + contralateral testicular RT 30 Gy (n=53)
Arm B: N/A (single-arm prospective study)
Primary endpoint: Event-free survival and overall survival
mFollow up: 64 month
Arm B: N/A (single-arm prospective study)
Primary endpoint: Event-free survival and overall survival
mFollow up: 64 month
Results
5-yr EFS: 74%
5-yr OS: 85%
Contralateral testicular relapse: 0% (with RT); historical ~15–30% without RT
CNS relapse: 6% despite intrathecal prophylaxis
5-yr OS: 85%
Contralateral testicular relapse: 0% (with RT); historical ~15–30% without RT
CNS relapse: 6% despite intrathecal prophylaxis
Adverse events
Main adverse events: Contralateral testicular RT led to permanent azoospermia in the majority of patients (sperm banking recommended before RT). No other significant RT-related late effects at this follow-up. R-CHOP toxicities standard.
Conclusions
R-CHOP + intrathecal MTX + contralateral testicular RT achieves 5-yr OS of 85% in PT-DLBCL. Contralateral testicular RT eliminates the characteristic relapse pattern in the contralateral testis, and is a critical component of treatment. CNS relapse remains a challenge despite intrathecal prophylaxis.
Key Limitations
Key Limitations: Small single-arm study (n=53). CNS prophylaxis with intrathecal MTX appears insufficient to prevent CNS relapse (~6%); high-dose IV systemic MTX may be more effective. No randomized comparison with R-CHOP alone or without contralateral testicular RT.
Clinical Context
IELSG-10 established the current standard for PT-DLBCL: R-CHOP × 6 + contralateral testicular RT 25–30 Gy + CNS prophylaxis (systemic high-dose MTX preferred per updated guidelines). NCCN and ESMO guidelines incorporate these findings. Sperm banking must be discussed before contralateral testicular RT.
References
References: Vitolo U et al, JCO 2011 (IELSG-10)