Hypofractionated re-irradiation of large-sized recurrent breast cancer with thermography-controlled, contact-free water-filtered infra-red-A hyperthermia: a retrospective study of 73 patients

Abstract

Purpose: Evaluation of the efficacy and toxicity of a new setup of thermographically controlled waterfiltered infra-red-A (wIRA) superficial hyperthermia (HT) combined with hypofractionated re-irradiation (re-RT) to treat large-sized breast cancer recurrences. Methods: Records of 73 heavily pre-irradiated patients with 103 treatment regions, treated from September 2009 to July 2015 were retrospectively analysed. Sixty-four patients with macroscopic disease were treated with 94 regions including 46 patients with lymphangiosis carcinomatosa. Hypofractionated RT consisted of 4 Gy once per week up to a total dose of 20 Gy delivered within 1-4 min after wIRA-HT. Heating of tumour nodules and diffusely spreading cancer lesions was performed under real-time thermographic temperature monitoring, maintaining the maximum skin temperature in the ROI between 42 C and 43 C, achieving intratumoural temperatures up to a depth of 2 cm between 39.5 C and 42 C. Seventeen patients received re-re-irradiation (re-re-RT) using the same HT/RT-treatment schedule. Results: Response rates in patients with macroscopic disease: 61% CR, 33% PR, 5% NC and 1% PD. Local control throughout life time after CR of macroscopic disease: 59%. All nine patients with microscopic disease had CR and local control throughout lifetime. Only grade 1 toxicities were observed. Conclusions: Application of thermographically controlled wIRA-HT combined with extremely low-dose re-irradiation provides good local control throughout lifetime of heavily pre-treated breast cancer recurrences. The twin wIRA radiator provides a sufficiently homogeneous heat deposition for the treatment of larger areas. The time lag between HT and re-RT is substantially reduced. The possibility of rere-RT opens new therapeutic options for the future. ARTICLE HISTORY

Biophysical and photobiological basics of water-filtered infrared-A hyperthermia of superficial tumors

“…At steady-state surface temperatures of 42 C, tissue temperatures !40 C were assessed up to a depth of approximately 15 mm, temperatures !39 C up to a depth of about 30 mm [12,13,49]. In cases of restricted convective transport or if fat tissue layers reduce conductive heat transport, tissue temperatures may Figure 9.…”

“…Mean temperature profile during wIRA exposure under steady-state conditions. Measured data in normal tissues [49] (open squares), tumor tissues [12] (open circles) and in recurrent breast cancers [13] (solid triangles). phantom was divided along a vertical plane into two halves, so that the depth of maximum temperature increase could be assessed.…”

“…Moreover, wIRA can reach blood vessels effectively within the range of the above mentioned penetration depths and, therefore, can transfer radiative energy into the circulating blood. Consequently, wIRA allows for the application of (a) prolonged therapeutically relevant exposure times using approximately two-times higher irradiances without causing pain [39] and severe skin toxicities [13] (200 mW/cm 2 versus <100 mW/cm 2 uHR, the so-called 'conventional IR-A'), and (a) faster and deeper heat extension within (tumor) tissues [38].…”

“…Using an upgraded, thermographically controlled 2-wIRAradiator system, Notter et al [13] have treated large-sized (broad, superficial) heavily pretreated breast cancer recurrences (and re-recurrences) with wIRA immediately followed by hypofractionated RT (5 Â 4 Gy, 1/week). Response rates in this retrospective study were 61% CR and 33% PR, respectively.…”

Planning, optimisation and evaluation of hyperthermia treatments

“…For example, locoregional hyperthermia using phased array systems with one or more rings of antennas surrounding the patient is applied to deep-seated tumours [6][7][8], whereas superficial hyperthermia is applied to tumours up to 4 cm depth from the skin [9][10][11][12][13]. Intraluminal or intracavitary heating can be applied when the tumour is accessible through an existing lumen or cavity [14,15].…”