Relationship between thermal dose and outcome in thermoradiotherapy treatments for superficial recurrences of breast cancer: data from a phase III trial Sherar, M.; Liu, F.F.; Pintilie, M.; Levin, W.; Hunt, J.; Hill, R.; Hand, J.; Vernon, C.; van Rhoon, G.; van der Zee, J.; González González, D.; van Dijk, J.D.P.; Whaley, J.; Machin, D. Published in:International Journal of Radiation Oncology Biology Physics DOI:10.1016/S0360-3016(97)00333-7 Link to publicationCitation for published version (APA): Sherar, M., Liu, F. F., Pintilie, M., Levin, W., Hunt, J., Hill, R., ... Machin, D. (1997). Relationship between thermal dose and outcome in thermoradiotherapy treatments for superficial recurrences of breast cancer: data from a phase III trial. International Journal of Radiation Oncology Biology Physics, 39, 371-380. https://doi.org/10.1016/S0360-3016(97)00333-7 General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Purpose: The objective of this study was to determine whether the thermal tmtments and other thermal Pactors correlate with outcome after combined carcinoma recurrences. Data were from the combined hyperthermia and radiation tmktment arms 0Pfour PhaseResuits: Five thermal parameters were tested, ail associated with the iow regions of the measur4 &@&tions. Max(TDmin) and Sum(TDmin) were associated with c rawrs representative of the low end of the measured temperature complete response rate, local disease-free survival, time to local failure and overail survival. 0 1997 Elsevier Science Inc.Hyperthermia, Randomized trial, Thermal dose, Outcome, Breast cancer, Recurrence. INTRODUCTIONWe recently reported that hypeitheimia is an effective adjunct to radiation in the treatment of chest wall recnrrences of breast carcinoma (1 I). This result is consistent with that of a recent trial of the effect of hypertherrnia on the response of malignant melanoma (19) and neck node metastases from head and neck cancer (27). However, other studies have shown no benefit in the addition of hyperthermia to radiation either for the treatment of chest wall recumnces of breast cancer using external heating (22,23), or for interstitial heating of miscellaneous tumors (9)

There is uncertainty regarding the risk posed by magnetic resonance imaging (MRI) examinations to pregnant patients. The most frequently used methods, such as single-shot fast spin echo (ssFSE), often require operation at the specific absorption rate (SAR) limits imposed by safety guidelines. With the introduction of higher-field systems, such limits will be even more significant for fetal imaging. An electromagnetic solver based on the time domain finite integration technique (FIT) was used to predict SAR in an anatomically realistic model of a pregnant patient (28 weeks' gestation) associated with the radiofrequency (RF) fields from birdcage body coils typical of 1.5 T and 3 T MRI systems (i.e., operating at approximately 64 and 127 MHz, respectively). The results suggest that 1) the highest local SAR is in the mother, with the fetus being exposed to a peak of approximately 40 -60% of that value at 64 MHz, increasing to approximately 50 -70% at 127 MHz; 2) compliance with U.S. MRI is increasingly being used to image both mother and fetus because it provides excellent delineation of the cerebral anatomy (1). It is particularly useful when ultrasound diagnostic imaging is inadequate, or when important information is needed that would otherwise require exposure to ionizing radiation (e.g., X-ray CT). Although there is no indication that the use of clinical MR procedures during pregnancy produces adverse effects, the safety of such procedures has not been proven (2,3), and there is currently a significant level of uncertainty regarding the risk posed by MRI examinations to pregnant patients (4). This situation is reflected in the differences among recent guidelines regarding exposure of pregnant patients (5-7).Studies using various animal models have shown that hyperthermia during pregnancy can be associated with resorption of the embryo, expulsion of the fetus at a nonviable stage of gestation, fetal death, central nervous system defects, and cardiovascular malformations (8). The threshold of effect in many species begins at about 1.5°C above normal core body temperature; however, accurate determinations of the thermal dose (in terms of temperature and duration) threshold for effect are sparse. In humans, neural tube and facial defects have also been found in children whose mothers had undergone prolonged or repeated periods of hyperthermia (Ն39°C for 24 hr or longer) during the first trimester of pregnancy (9). Increases in congenital abnormalities, abortions, and fetal vascular disruption have also been associated with the mother undergoing a febrile illness. Such effects have been observed following hyperthermal exposures beyond the first trimester (8). It has been suggested that adverse effects on embryonic or fetal development will be avoided if the temperature of the fetus does not exceed 38°C, and the body temperature of pregnant women does not rise by more than 0.5°C (7).Experimental findings regarding the effects of RF fields used for MR procedures and the pertinent safety aspects of pregnancy are equivo...

A method for focusing high intensity ultrasound through a rib cage that aims to minimize heating of the ribs whilst maintaining high intensities at the focus (or foci) is proposed and tested theoretically and experimentally. Two approaches, one based on geometric acoustics and the other accounting for diffraction effects associated with propagation through the rib cage, are investigated theoretically for idealized source conditions. It is shown that for an idealized radiator the diffraction approach provides a 23% gain in peak intensity and results in significantly less power losses on the ribs (1% versus 7.5% of the irradiated power) compared with the geometric one. A 2D 1-MHz phased array with 254 randomly distributed elements, tissue mimicking phantoms, and samples of porcine rib cages are used in experiments; the geometric approach is used to configure how the array is driven. Intensity distributions are measured in the plane of the ribs and in the focal plane using an infra-red camera. Theoretical and experimental results show that it is possible to provide adequate focusing through the ribs without overheating them for a single focus and several foci, including steering at ± 10–15 mm off and ± 20 mm along the array axis. Focus splitting due to the periodic spatial structure of ribs is demonstrated both in simulations and experiments; the parameters of splitting are quantified. The ability to produce thermal lesions with a split focal pattern in ex vivo porcine tissue placed beyond the rib phantom is also demonstrated. The results suggest that the method is potentially useful for clinical applications of HIFU for which the rib cage lies between the transducer(s) and the targeted tissue.