Dynamic T1-weighted magnetic resonance imaging of interstitial laser photocoagulation in the liver: Observations on in vivo temperature sensitivity

Fried, Marvin P.; Morrison, Paul R.; Hushek, Stephen G.; Kernahan, Gilberto A.; Jólesz, Ferenc A.

doi:10.1002/(sici)1096-9101(1996)18:4<410::aid-lsm11>3.0.co;2-7

Cited by 39 publications

(21 citation statements)

References 21 publications

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“…In clinical use, it will be important to check that no pneumothorax is developing during treatment. The thermal e#ects of Nd: YAG laser have been applied in lung volume reduction surgery to seal small airways in bullous areas [28]. PDT would not be expected to do this, so there may be a slightly lower risk of pneumothorax with ILP compared with PDT.…”

Section: Discussionmentioning

confidence: 99%

Interstitial Laser Photocoagulation and Interstitial Photodynamic Therapy of Normal Lung Parenchyma in the Pig

et al. 2001

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Interstitial laser photocoagulation (ILP) and interstitial photodynamic therapy (PDT) involve delivery of light to lesions in solid organs using thin fibres passed through needles inserted percutaneously under image guidance. In ILP, the laser energy heats the tissue, whereas in PDT it activates a previously administered photosensitising agent. This study looks at their potential for treating localised, small, peripheral lung cancers in patients unsuitable for surgery. Experiments were undertaken on nine normal pigs, up to four fibres being inserted into the lung parenchyma percutaneously under X-ray guidance (ILP: 2-3 W, 1000 q/fibre, from 805 nm diode laser, PDT, 100-200 J/fibre from 652 nm diode laser at 50-100 W, 3 days after 0.15 mg/kg mTHPC). Animals were killed from 3 days to 3 months later and the treated areas examined macroscopically and microscopically. Both techniques were well tolerated, producing well-defined, localised lesions, typically 3.5 x 2 x 2 cm using four fibres. Histology showed thermal coagulative necrosis after ILP and haemorrhagic necrosis after PDT. Early small haematomas and late cavitation were sometimes seen after ILP, but not after PDT. PDT lesions healed with preservation of larger arteries and bronchi in the treated area. A few small pneumothoraces were seen which resolved spontaneously, probably related to the chest wall puncture. It was concluded that ILP and PDT lesions of a size large enough to cover a small tumour can be made safely in the lung parenchyma, although healing was better after PDT. Pilot clinical studies with both techniques are now justified on carefully selected patients.

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Section: Discussionmentioning

confidence: 99%

Interstitial Laser Photocoagulation and Interstitial Photodynamic Therapy of Normal Lung Parenchyma in the Pig

et al. 2001

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“…However, both the T 1 and its temperature dependence differ between tissues. Nonlinear effects have been observed in particular when coagulation occurs (27)(28)(29). This is not surprising since exchange processes and effective tumbling rates of water may be influenced drastically.…”

Section: Temperature Mri Based On the T 1 Relaxation Time Of Water Prmentioning

confidence: 99%

Magnetic resonance temperature imaging for guidance of thermotherapy

Quesson

Zwart

Moonen

2000

J. Magn. Reson. Imaging

492

430

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“…[21][22][23]. As T1-weighted sequences are particularly dependent on the type and status of the tissue (24,25), they are mainly recommended in low-field systems because of their higher contrast. On the contrary, diffusion methods still suffer from technical and methodical limitations in clinical practice (26).…”

Section: Introductionmentioning

confidence: 99%

Noninvasive Magnetic Resonance Thermography of Recurrent Rectal Carcinoma in a 1.5 Tesla Hybrid System

Gellermann¹,

Wlodarczyk²,

Hildebrandt³

et al. 2005

Cancer Research

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To implement noninvasive thermometry, we installed a hybrid system consisting of a radiofrequency multiantenna applicator (SIGMA-Eye) for deep hyperthermia (BSD-2000/3D) integrated into the gantry of a 1.5 Tesla magnetic resonance (MR) tomograph Symphony. This system can record MR data during radiofrequency heating and is suitable for application and evaluation of methods for MR thermography. In 15 patients with preirradiated pelvic rectal recurrences, we acquired phase data sets (25 slices) every 10 to 15 minutes over the treatment time (60-90 minutes) using gradient echo sequences (echo time = 20 ms), transformed the phase differences to MR temperatures, and fused the color-coded MR-temperature distributions with anatomic T1-weighted MR data sets. We could generate one complete series of MR data sets per patient with satisfactory quality for further analysis. In fat, muscle, water bolus, prostate, bladder, and tumor, we delineated regions of interest (ROI), used the fat ROI for drift correction by transforming these regions to a phase shift zero, and evaluated the MR-temperature frequency distributions. Mean MR temperatures (T MR ), maximum T MR , full width half maximum (FWHM), and other descriptors of tumors and normal tissues were noninvasively derived and their dependencies outlined. In 8 of 15 patients, direct temperature measurements in reference points were available. We correlated the tumor MR temperatures with direct measurements, clinical response, and tumor features (volume and location), and found reasonable trends and correlations. Therefore, the mean T MR of the tumor might be useful as a variable to evaluate the quality and effectivity of heat treatments, and consequently as optimization variable. Feasibility of noninvasive MR thermography for regional hyperthermia has been shown and should be further investigated. (Cancer Res 2005; 65(13): 5872-80)

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Dynamic T1-weighted magnetic resonance imaging of interstitial laser photocoagulation in the liver: Observations on in vivo temperature sensitivity

Cited by 39 publications

References 21 publications

Interstitial Laser Photocoagulation and Interstitial Photodynamic Therapy of Normal Lung Parenchyma in the Pig

Interstitial Laser Photocoagulation and Interstitial Photodynamic Therapy of Normal Lung Parenchyma in the Pig

Magnetic resonance temperature imaging for guidance of thermotherapy

Noninvasive Magnetic Resonance Thermography of Recurrent Rectal Carcinoma in a 1.5 Tesla Hybrid System

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