Minimally invasive palliative tumor therapy guided by imaging techniques: the UCLA experience

The Rationale for "Laser-Induced Thermal Therapy (LITT) and Intratumoral Cisplatin" Approach for Cancer Treatment

Cisplatin is one of the most widely used anticancer drugs in the treatment of various types of solid human cancers, as well as germ cell tumors, sarcomas, and lymphomas. Strong evidence from research has demonstrated higher efficacy of a combination of cisplatin and derivatives, together with hyperthermia and light, in overcoming drug resistance and improving tumoricidal efficacy. It is well known that the antioncogenic potential of CDDP is markedly enhanced by hyperthermia compared to drug treatment alone. However, more recently, accelerators of high energy particles, such as synchrotrons, have been used to produce powerful and monochromatizable radiation to induce an Auger electron cascade in cis-platinum molecules. This is the concept that makes photoactivation of cis-platinum theoretically possible. Both heat and light increase cisplatin anticancer activity via multiple mechanisms, generating DNA lesions by interacting with purine bases in DNA followed by activation of several signal transduction pathways which finally lead to apoptosis. For the past twenty-seven years, our group has developed infrared photo-thermal activation of cisplatin for cancer treatment from bench to bedside. The future development of photoactivatable prodrugs of platinum-based agents injected intratumorally will increase selectivity, lower toxicity and increase efficacy of this important class of antitumor drugs, particularly when treating tumors accessible to laser-based fiber-optic devices, as in head and neck cancer. In this article, the mechanistic rationale of combined intratumor injections of cisplatin and laser-induced thermal therapy (CDDP-LITT) and the clinical application of such minimally invasive treatment for cancer are reviewed.

The role of surgery in the palliation of head and neck cancer

PURPOSE OF REVIEW

The public demands that 'all modes of treatment' should be offered to patients who present with head and neck cancer. Up to 40% of patients present with advanced stage disease, of whom some 10% have metastatic disease and are currently deemed incurable. This review summarizes the current role and philosophy of surgical interventions in the palliation of head and neck cancer.

RECENT FINDINGS

Patients who present with advanced or recurrent head and neck cancers over the past decade have been offered nonsurgical palliative treatments of radiotherapy with or without chemotherapy, with variable responses. The aims are to achieve tumour shrinkage and gain effective relief of symptoms, such as pain, breathing and swallowing. The use of surgery in the palliation of disease and its symptoms has declined significantly since the 1980s. Within the concept of multidisciplinary clinical working as the 'gold standard' for the provision of optimum care for the head and neck patient, the place for surgery should be discussed within the many options available currently.

SUMMARY

Patients who present with advanced, incurable or recurrent head and neck cancer should be made aware of their prognosis and the potential need and benefits of palliative care. The active involvement of patients and their carers, their desires and wishes should be the prime consideration for any interventions. Careful selection of suitable patients can achieve prolonged symptom relief safely and result in an improvement in their quality of living. The ultimate goal should incorporate not only quality of life but quality of dying.

Outcomes of laser thermal therapy for recurrent head and neck cancer

Objective: To review the outcomes of a phase II study using laser-induced thermal therapy (LITT) as a palliative treatment for 106 patients with recurrent head and neck tumors.

Study Design: Retrospective study.

Setting: Tertiary hospital in the United States.

Subjects and Methods: The primary endpoints were tumor response and survival. Prognostic values were assessed by the Kaplan-Meier method.

Results: The best results were seen in oral cavity tumors, in which mean survival was 29.1 months, as compared to neck tumors (mean 14.4 ± 6.9 months; range 7.5-20.7 months; with a 95% confidence interval). Further analysis showed that clinical factors such as gender, smoking, and alcohol use were not indicators of poor prognosis, whereas neck disease and tumor stage at first treatment were relevant factors.

Conclusion: In this study, 40 out of 106 patients treated by LITT remained alive at the end of our follow-up, and a complete response was seen in 24 (22.6%) patients. The highest response rate was seen in oral cavity tumors, which suggests that tumor location at this site may be a predictor of favorable outcome with LITT.

Ultrasound-guided laser-induced thermal therapy of malignant cervical adenopathy

OBJECTIVES

Laser-induced thermal therapy (LITT) for cancer is a technique whereby a source of energy (laser, radiofrequency, ultrasonic, cryoenergy, and so on) is directly applied into a tumor at various depths. Recent studies have demonstrated the efficiency of ultrasound (UTZ) and magnetic resonance imaging (MRI) for real- or "near" real-time tumor and vessel identification as well as monitoring and quantifying energy-induced tissue damage. The objective of this study is to report UCLA's experience using UTZ monitoring of Nd:YAG laser thermal ablation of malignant cervical adenopathy in a phase II study.

STUDY DESIGN

The authors conducted a retrospective study of patients treated at a tertiary medical center.

METHODS

Forty-seven patients with a total of 55 neck tumors were treated on an outpatient basis in the operating room using UTZ for image-guided laser interstitial thermal therapy. Laser energy was delivered through an SLT Nd:YAG laser powered at 30 W (power density: 2,200 J/cm).

RESULTS

Eleven patients had a complete response ranging from 5.5 to 90 months (mean, 22.1 months). Based on the findings of this study, it was possible to show that proximity to the carotid artery was the most relevant factor in projecting patient survival. Patients' individual treatment analysis and final outcome are further discussed.

CONCLUSIONS

LITT ablation of malignant cervical adenopathy was considered safe and feasible. No intraoperative complications occurred. Further development of this technique applying laser energy delivery to mathematical imaging models should lead to more effective tumor palliation as an alternative to surgery.

Intratumor injections of cisplatin and laser thermal therapy for palliative treatment of recurrent cancer

OBJECTIVE

The aim of this work was to report initial findings on the clinical application of intratumor injection of cisplatin in a gel (CDDP/gel) combined with laser-induced thermal therapy (LITT) for cancer treatment in a single patient with advanced stage disease.

BACKGROUND DATA

LITT with the neodymium:yttriumaluminum- garnet (Nd:YAG) laser via fiberoptics is a precise, minimally invasive alternative for thermoablation of unresectable or recurrent head and neck neoplasms, but recurrence is often seen at the treatment margins. Combining intratumor chemotherapy with interstitial laser should be most effective using drugs with thermally enhanced toxicity, such as cisplatin. The CDDP/gel therapeutic implant was expected to retain a higher concentration of cisplatin in the tumor margins for improved LITT treatment of the patient presented.

METHODS

In this case report, the cisplatin dose was 0.25 mL gel/cm(3) tumor volume (20 mg of CDDP) followed by LITT (Nd:YAG laser, 50 W, PD = 2,200 J/cm(2)) after the chemotherapy session.

RESULTS

The patient responded with local tumor eradication, and no signs of systemic toxicity were observed related to this therapy. However, the patient developed progressive metastatic disease in the lungs and died 2.5 months later.

CONCLUSIONS

This is a report of a patient with an accessible solid tumor who was treated with intratumor injection of CDDP/gel followed by LITT, which proved to be feasible. Based on preclinical evidence obtained at UCLA and the results of this study, we are encouraged to continue our refinement of LITT combined with chemotherapy for cancer treatment.

Magnetic resonance image-guided thermal ablations

Magnetic resonance imaging (MRI)-based monitoring has been shown in recent years to enhance the effectiveness of minimally or noninvasive thermal therapy techniques, such as laser, radiofrequency, microwave, ultrasound, and cryosurgery. MRI's unique soft-tissue contrast and ability to image in three dimensions and in any orientation make it extremely useful for treatment planning and probe localization. The temperature sensitivity of several intrinsic parameters enables MRI to visualize and quantify the progress of ongoing thermal treatment. MRI is sensitive to thermally induced tissue changes resulting from the therapies, giving the physician a method to determine the success or failure of the treatment. These methods of using MRI for planning, guiding, and monitoring thermal therapies are reviewed.

Palliative laser therapy for recurrent head and neck cancer: a Phase II clinical study

OBJECTIVES

Laser therapy is becoming a more precise, minimally invasive alternative for tumor ablation. Recent reports confirm successful palliation of pain and functional disabilities in patients with advanced deep carcinoma of the head and neck using interstitial laser phototherapy (ILT).

STUDY DESIGN, PATIENTS, AND METHODS

The current study describes an ongoing Phase II trial of neodymium/yttrium-aluminum-garnet (Nd:YAG) laser therapy for palliation of advanced head and neck cancer. A total of 40 advanced cancer patients have been entered into this protocol (25 men and 15 women).

RESULTS

Nineteen of these patients had no evidence of recurrence after ILT with an average follow-up of 11 months (range, 2 to 24 mo). Currently, 19 of these patients are alive, 14 with tumor remission and six with persistent disease. A total of 79 tumor sites received ILT with 43 (54.5%) completely ablated. Stratified by tumor site, ILT led to a complete response in 21 of 24 in the oral cavity, eight of 28 neck tumors, four of 10 in skin, and 10 of 17 in other sites. The procedure was well tolerated in most cases and was repeated at intervals in patients with residual disease or recurrences for a total of 118 laser treatments (average, 2.95 treatments per patient).

CONCLUSIONS

The results suggest that ILT can be performed safely and repeated as needed, and may be less costly than conventional surgery for head and neck cancer. However, additional follow-up is needed to obtain convincing evidence of long-term therapeutic benefits.

Laser photochemotherapy with anthracyclines on cultured human squamous carcinoma cells

A new treatment for cancer has been tested in vitro using light-sensitive anthracyclines followed by laser photoactivation, as described by several investigators. We previously reported 10-fold enhanced laser killing after 2 hours of incubation with daunomycin by cultured human carcinoma cells. This short-term uptake leads to drug localization in cytoplasmic and membrane sites prior to nuclear accumulation and topoisomerase inhibition. In the present study, daunomycin was incubated for 2 or 24 hours with P3 squamous carcinoma cells to directly compare cytoplasmic vs. nuclear drug targeting before and after KTP-532 laser activation. Monolayer cultures of the P3 cells sensitized with daunomycin for 2 hours, then chilled (4 degree C), and exposed to the KTP laser (532 nm, 94.2 J/cm2) had a 2- to 10-fold increased therapeutic response compared with drug or laser alone when measured by MTT tetrazolium assays. After 24 hours of incubation with daunomycin, the chemotherapeutic response of P3 tumor cells was amplified 2-fold by laser exposure. The results suggest that daunomycin and laser treatment can be combined for improved therapy of human cancer.

Dynamic MRI-guided interstitial laser therapy: a new technique for minimally invasive surgery

Interstitial laser therapy (ILT) is a promising therapeutic technique in which laser energy is delivered percutaneously to various depths in tissue. In this study, the authors compared high-speed magnetic resonance imaging (MRI) of ILT in tissues during treatment with post-treatment histopathologic specimens. The use of 5-second MRI scans allowed detection of thermal damage by the 1064-nm neodymium:yttrium-aluminum-garnet laser in ex vivo liver and brain tissues. These tissues were treated by ILT with 20 W of laser output for 5 to 30 seconds via a 600-microns fiberoptic inserted 1 cm into the specimens at a power density of 7 kW/cm2 at the tip of the bare fiber. Sequential MRI measurements of lesion areas made during and after treatment were compared to measurements of laser-induced tissue damage in histopathologic sections. Fast MRI scans and tissue histology both demonstrated increased lesion size with time of ILT. Serial images obtained during ILT detected thermal changes as areas of low signal intensity that exceeded the size of the post-treatment lesions as measured on either final MRI or histology. The thermal effects detectable by these high-speed MRI sequences can be used to monitor laser-induced tissue changes during therapy, thereby providing a valuable noninvasive method for the intraoperative assessment of heat distribution during ILT.

Interstitial laser photochemotherapy with new anthrapyrazole drugs for the treatment of xenograft tumors

Photodynamic therapy (PDT) with lasers and new dyes has gained popularity in recent years as a minimally invasive technique with high tumoricidal effects in vitro and in some cancer patients. However, because new laser dyes are not FDA approved at present, the clinical evaluation of PDT may be years away. During the past 6 years we have used laser alone for photothermal ablation in both preclinical studies and in a large number of patients with an observed 60% tumor response rate. The 40% treatment failure led us to explore the possibility of combined therapy with lasers and standard chemotherapeutic drugs. We have recently tested a promising preclinical alternative using implantation of a bare 600-microns KTP 532 laser fiberoptic in multiple tumor sites 30 min after intratumor injection of the anthrapyrazole DUP-941. As a control, this drug was injected in 3 sites of P3 human squamous cell tumor transplants in nude mice, which led to tumor stasis without regression. Similar 400-600 mm3 tumors exposed to laser illumination alone (0.8 W for 5 sec) at multiple sites resulted in tumor regrowth after 10 weeks in 80% of the animals. However, combining interstitial laser illumination with intratumor DUP-941 injections led to complete tumor regression in 85% of the mice. We propose that intratumor drug injection followed by interstitial laser fiberoptic treatment represents a potentially useful new method for tumor ablation in advanced cancer patients.

Laser photochemotherapy: a less invasive approach for treatment of cancer

The effectiveness of combining surgery with chemo- and radiation therapy in treatment of human cancer provides a useful model for further development of new multimodality approaches including laser photochemotherapy. Laser endoscopy often is a useful treatment for obstructive tumors in airways, but interstitial laser fiberoptics is becoming a more precise, minimally invasive alternative for ablation of unresectable or recurrent neoplasms. Combining intratumor chemotherapy with laser energy delivery via interstitial fiberoptics should be most effective using drugs activated by photothermal energy. A number of investigators have shown that anthracyclines and cis-platinum are likely candidates for light or heat activation in cancer cells. An advantage of anthracyclines is their dual role as antitumor drugs and as photosensitizers. Because they are effective chemotherapy agents without photoactivation, two approaches are possible to increase tumor responses. Maximum tolerated dose followed by photoillumination via laser fiberoptics can be used to obtain better tumor palliation. Improved treatment response to lower intratumor drug levels after laser activation also should reduce systemic toxicity. Preclinical studies and recent case reports from several groups suggest photochemotherapy with currently approved drugs and lasers may soon become an attractive alternative for treatment of recurrent tumors in cancer patients.