The impact of the time interval between radiation and hyperthermia on clinical outcome in patients with locally advanced cervical cancer

The benefit of hyperthermia combined with radiotherapy is well-acknowledged for patients with locally advanced cervical cancer (LACC) (1-3). However, recently a discussion evolved on the optimal time interval between radiotherapy and hyperthermia. Kroesen et al. (4) recently reported a retrospective analysis of factors influencing clinical results of treatment with radiotherapy and hyperthermia in a large cohort of locally advanced cervical cancer patients (LACC) at ErasmusMC in Rotterdam. They concluded that there is no detrimental effect of prolonged intervals on clinical outcome within a time frame of 4 h between radiotherapy and hyperthermia. Kroesen et al. thereby explicitly dismissed the findings of Van Leeuwen et al. (5) in a smaller cohort of LACC patients treated at the Academic Medical Center (AMC) of the University of Amsterdam. In that study longer time intervals and lower tumor temperatures were both found to have a highly negative effect on in-field tumor control (time interval: P = 0.021, in multivariable analysis p = 0.007) and overall survival (idem: P = 0.015, in multivariable analysis p = 0.012), where it is important to note that the median time intervals between radiotherapy and hyperthermia were ∼60 and ∼90 min for the short and long time interval subgroups of patients, respectively.