以下的文献介绍的是光动疗PDT。但有不少治疗细节可供将来DIY声动疗参考。我简单翻译其中几个关键部分。看来二氢卟吩是个不错的选择，关键是能否被光源或声源充分激发。
20 Issue 1 Page 21 - February 2004
doi:10.1111/j.1600-0781.2004.00078.x
Photodynamic therapy with chlorin e6 for skin metastases of melanoma
http://www.isla-laser.org/wp-con ... 21-26-Full-Text.pdf
针对皮肤转移的黑色素瘤采用二氢卟吩（chlorin e6）的光动疗（PDT）
Sergey V. Sheleg 1 , Edvard A. Zhavrid 1 , Tatsiana V. Khodina 1 , Georgy A.
Kochubeev 2 , Yury P. Istomin 1 , Vadim N. Chalov 1 , Ivan N. Zhuravkin 1
Background: Photodynamic therapy (PDT) has been successfully
applied in clinical settings to destroy neoplasms, but the efficacy of such
a treatment is dependent on the type of neoplasm and the
photosynthesizer used. Here, we perform a clinical assessment of PDT
for skin metastases of pigmented melanoma using chlorin e6.
Study design/Materials and methods: PDT with chlorin e6
photosensitizer was administered to 14 patients with skin metastases
from melanoma (10 females, four males, mean age 49.6 years). Chlorin
e6 at a dose of 5 mg/kg of patient's weight was intravenously injected.
The treatment course consisted of two courses of PDT exposure 1 h
after intravenous chlorin e6 injection and 24 h post-injection. The light
energy density for each skin tumor was 80 120 J/cm2 per treatment,
with a light power density of 250 300 mW/cm2.
方法： 给14个患者（10女4男）经静脉输入光敏剂二氢卟吩（chlorin e6）。剂量为5mg/公斤体重。一疗程光照两次，第一次是静脉输入后1小时，第二次是静脉输入后24小时。光能强度为80-120焦耳/平方厘米，功率强度为250-300 mW/平方厘米。（声动疗可参考功率强度）
Results: All skin melanoma metastases that received PDT showed
complete regression with no recurrence during the study period. The
complete response of all skin metastases from melanoma occurred in
eight cases after one PDT treatment. In the remaining six individuals,
tumors required multiple PDT courses prior to complete regression. No
cases of photodermatitis were registered. The Karnofsky performance
scale score of the patients with skin metastases from melanoma showed
no significant difference before and after PDT. No patients had
significant changes in blood cell counts that would indicate chlorin e6
systemic toxic effect. Blood chemistry and urinalysis did not show any
evidence of chlorin e6 renal and hepatic injury.
结果： 接受PDT之后，所有皮肤上转移的黑色素瘤完全消失（complete regression），在研究期间（24个月）无复发。经过1疗程PDT，8例呈完全应答。其余6例经多疗程后完全应答。患者血细胞数目均无大幅度的变化，即无指证二氢卟吩有系统性的毒性作用。通过血生化与尿分析，无证据显示二氢卟吩会导致肾和肝的损伤。
Conclusions: PDT with chlorin e6 for skin metastases from melanoma
is effective and well tolerated. Further clinical investigation of PDT with
chlorin e6 is warranted.
Photodynamic therapy (PDT) is essentially a new approach to the diagnosis and
treatment of patients with malignant tumors (1, 2). At present, 5-aminolaevulinic
acid (ALA) and some hematoporphyrin derivatives (HPDs, photofrin 2) are being
widely used as PDT photosensitizers (2 4). PDT is implemented by injecting
various photosensitizer dyes capable of selective accumulation in malignant
tumors, followed by exposure to laser radiation (in the range of active absorption)
that triggers the destruction of tumor cells in the presence of oxygen. The
employment of laser equipment and a special guided light has made it possible to
administer PDT in the treatment of pulmonary, esophageal, and gastric cancer (5
10). The advantages of PDT over conventional methods of malignant neoplasm
treatment are that it allows selectivity of tumor destruction and repeated courses of
treatment if necessary.
The efficacy of PDT was demonstrated in the treatment of basal cell carcinoma of
the skin and metastases to the skin from breast cancer (2, 11). However, PDT for
skin metastases from melanoma produced a clinical effect only in 20 30% of the
patients (12, 13). The researchers hypothesized that this deficit might be due to
the presence of a large amount of melanin pigment in tumor cells of pigmented
melanoma, which intensively absorb optical radiation, resulting in only a shallow
light penetration into the tumor tissue. This has led to recent efforts by researchers
in the search for new and more effective photosensitizers, chlorin derivatives in
particular (14, 15).
Chlorin e6 was synthesized at the Laboratory of Photochemistry, National
Academy of Sciences of the Republic of Belarus (16). PDT techniques were
developed in experiments on animals with inoculated tumors and necrobiotic
changes were demonstrated to occur in the tumor tissue exposed to PDT with
chlorin e6, followed by subsequent regression of the transplanted tumors in rats
(17 19).
During the course of phase I clinical trials of PDT with chlorin e6, we established
that effective treatment with PDT is achieved at a chlorin e6 dose of 5 mg/kg or
higher, with the maximum tolerance dose of the drug being 18 mg/kg (20). The
major side effects of chlorin e6 are rigor, pain in the photoradiation area during the
course of PDT procedure, and an increase in body temperature.
Methods
Chlorin e6 photosensitizer
Chlorin e6 medical preparation produced by Dialek, Ltd (Minsk, Belarus白俄罗斯) was used
in all trials. Chlorin e6 at a dose of 5 mg/kg of patient's weight was dissolved in
200 ml of 0.9% sodium chloride solution and intravenously injected during a 30-
min period. One hour and 24 h post-injection, laser therapy was administered at
tumor sites. After the photosensitizer administration, all the patients spent a week
in a shaded ward. Two weeks after the treatment, patients were discharged and
advised to wear dark glasses and avoid exposing the skin to bright sunshine.
二氢卟吩溶化于200ml的0.9%浓度的生理盐水，30分钟内注射入静脉。第一个星期呆在遮光的室内，两星期后外出带墨镜，避免强光照射。
Patients
For 24 months beginning in January of 2000, PDT was given to 14 patients with
skin metastases from melanoma (10 females, four males, age mean 49.6 years).
The Karnofsky performance scale (KPS) score of the patients was at least 80 at
the time of enrollment (21). Pathologic examinations of one or two excised
melanoma skin metastases were performed in all cases of multiple melanoma skin
metastases before starting PDT.
Thirteen patients presented with melanoma progression after previous multi-modal
treatment. All these patients had prolongation of skin metastases despite multiple
courses of chemotherapy. No distant metastases into internal organs were
observed. A female patient (case 13, Table 1) had an initial diagnosis of
melanoma of the pedal skin with multiple metastases to the pedal skin. Another
female patient (case 7, Table 1) had multiple (150) metastases to the skin of the
right inferior limb. Eight patients received one PDT course, three patients received
two courses, and three patients received between three and five PDT courses.
病例7的右下肢有150处转移。所有的患者均无内脏转移。都做过多疗程的化疗。8个患者做了一个疗程PDT。3个患者做了两个疗程，3个患者做了3-5个疗程。
The clinical details of the 14 patients with melanoma skin metastases are summarized
in Table 1. The Scientific and Ethic Committees of N.N. Alexandrov Research
Institute of Oncology and Medical Radiology approved the protocol in January
1997, and all patients gave informed consent.
Immediately after the PDT treatment, the exposed area became pale gray with
bright skin hyperemia surrounding it. Three days later, the tumor and up to 5 mm
of the adjacent skin grew dark violet. Ten to fifteen days after photo-irradiation, a
dry crust appeared in the area, which was rejected 1 1.5 months later. The wound
completely healed 2.5 3 months after the treatment (Fig. 1). After crust rejection,
in all cases we performed non-invasive imprint cytologic examinations from the
bottom of the wound. No melanoma cells were seen in 13 cases after posttreatment
examination. Only one patient (case 13) still showed the presence of
melanoma cells after two courses of PDT, with additional treatment leading to
complete regression. After the third PDT course, we did not find melanoma cells in
the wound.
Parameters of PDT with chlorin e6
To administer PDT treatments, we used an LD 680 2000 laser unit (BioSpec, Ltd,
Moscow, Russia) complete set including fiber-optic guides for external application
with a microlens. The LD 680 2000 laser unit is based on a semiconductor laser
diode (the wavelength of the generated laser radiation 670 nm), and is intended for
PDT using photosensitizers with absorption in the spectral range of 660 690 nm.
Before the PDT treatment, the light spot diameter was established so as to insure
sufficient exposure of the peripheral part of the tumor. To achieve this goal, the
size of the irradiated area should be at least 20% larger than the tumor size.
辐照区直径要较肿瘤大至少20%。
We treated the lesions from one point of photo-irradiation only if their size was not
more than 1 cm in diameter. In case of a large lesion (diameter of lesion more than
1 cm), we administered PDT treatment from several focal points. The treatment
course consisted of two PDT exposures 1 and 24 h after intravenous chlorin e6
injection. The light energy density for each skin tumor per treatment was 80
120 J/cm2, with a light power density of 250 300 mW/cm2.
Statistical methods
We used the method described by Glass et al. (22) to determine the tumor surface
area before and after PDT courses. The survival rate of all patients was also
evaluated as of January 1, 2003. Survival curves for the patients were estimated
by the Kaplan Meier technique (23).
Results
Clinical efficacy of PDT with chlorin e6
All skin melanoma metastases treated with PDT showed complete regression
during the study without recurrence during the follow-up period. Complete
response (complete disappearance of all treated tumors) after one course of PDT
was seen in eight cases. A female patient with pedal skin melanoma and multiple
metastases to the pedal skin (case 13) receiving light radiation on a 3 cm thick
tumor presented with only a partial response after the first PDT course, and that
required three more courses of treatment separated by 2-month intervals to treat
additional melanomas.
13号女患者在接受第一疗程后，3公分厚的肿瘤只有部分应答，接着又做了3个疗程，每两疗程之间间隔2个月。
Another female patient (case 3) received five courses (with
1.5-month intervals) of PDT because of excessive number of skin metastases of
melanoma (120 tumors).
由于有120个皮肤转移瘤，3号女患者接受了5个疗程，每两疗程之间间隔1.5个月。
All the irradiated lesions in this case were cured after one
course of photo-irradiation. A complete response was seen in both cases following
the administration of additional therapy, and no new skin melanoma metastases
were seen during the course of follow up. In the remaining patients, the treatment
of all individual lesions yielded complete regression after one course of PDT and
newly appearing lesions were treated after additional courses, but PDT therapy
was terminated due to the advanced progression of melanoma. Despite complete
tumor destruction in these individuals, too many new metastases were seen posttreatment
to consider continuing PDT on new tumors.
No new tumor growth occurred in the photo-irradiation area in the cases of
complete response in the follow-up period of 6 24 months. The median overall
survival time for the patients (since the time surgery was performed) was 883 days
(Fig. 2). Eleven patients died due to the progression of melanoma (pulmonary,
cerebral, and hepatic metastases).
Side effects of PDT with chlorin e6
Chlorin e6 administration caused rigor and temperature rise up to
38temp1.txttemp1.txt°C in two patients. No cases of severe pain during PDT were
registered, but eight patients complained of pain for 2 5 days after PDT. They
were administered MST-Continuous 60 mg per os daily, for 3 5 days. No cases of
photodermatitis were noted. An increase of granulocytes was seen in all cases
(average granulocyte counts 1 week before PDT were 2.8±0.2 1000/ l compared
with 13.5±0.5 1000/ l 1 week after PDT). Three weeks after treatment, the
neutrophil levels returned to a normal range. Additional blood chemistry and
urinalysis did not show any evidence of chlorin e6 renal and hepatic injury. The
evaluation of the KPS score in the patients with skin metastases from melanoma
showed no significant difference before and after PDT (Table 1).
Discussion
HPD) in particular, are being widely used in clinical applications. However, these
preparations have a number of disadvantages restraining application of the
method:
(1)
As the light energy absorption maximum of those photosensitizers falls at
about 630 nm, the light sources of this wavelength provide a low
penetrability of photo-irradiation, which make it impossible to employ PDT
for deep-seated tumors.
(2)
Slow excretion of HPDs from the skin significantly increases the
probability of photodermatitis.
(3)
Low selectivity of the photosensitizer accumulation in malignant
neoplasms reduces penetrance of the malignancy.
For this reason, a keen interest is being displayed in identifying new sensitizers
that localize more effectively in tumors, absorb more intensely at longer
wavelengths, and can be prepared with high purity. Much of this interest has been
directed towards chlorins (reduced porphyrins), whose typical absorption is strong
in red light (14).
Chlorin e6 belongs to the chlorin compounds, which contain a number of
photophysical properties superior to those of HPD and photofrin 2. It possesses a
higher photodynamic activity under in vitro and in vivo conditions (17 19). In
contrast to photofrin, chlorin e6 absorption peak is in the long-wave spectral area
(660 nm), and this results in improved light penetrability in biological tissues.
Despite the available experience in the clinical application of chlorin derivatives
(tetrahydroxyphenyl chlorin (mTHPC, Foscan), mono-L-aspartyl chlorin e6 (Npe6))
in PDT for malignant tumors (oral cancer, basal cell carcinoma, early carcinomas
of the upper aerodigestive tract, mesothelioma, etc.), no reports can be found in
the literature on their use in the treatment of skin metastases from melanoma (24
29). Koderhold et al. (30) reported about their experience with PDT in dermatology.
They cured 15 patients with skin tumors (12 with basalioma, one with
mesothelioma of scrotum, one with Queyrat's erythroplasia, and one with skin
metastases of melanoma) using PDT with Photosan III. All patients were treated by
a dye argon laser system. The light dose was 50 80 J/cm2. The patient with skin
metastases of melanoma gave no response.
We used a power density of 250 300 mW/cm2 on the basis of the experimental in
vivo data of Michailov et al. (31). The authors used a total light dose of 360 J/cm2,
which was delivered at the rates of 260, 320, 380, 440, and 500 mW/cm2.
Complete tumor response was obtained with mice in 40% of cases following
380 mW/cm2.
PDT of malignancies at a power density of 250 and greater mW/cm2 can cause
the local tumor hyperthermic effect. According to the data of Kimel et al. (32),
damage to the chick chorioallantoic membrane vasculature due to combined
PDT+hyperthermia was compared with the outcome of the individual modalities,
and a synergistic effect of about 40% was observed. Leunig et al. (33) in their
research of evaluation of photodynamic therapy-induced heating of melanoma in
vivo also concluded that a combination of PDT and hyperthermia might act in an
additive, synergistic manner. We suppose that this possible synergistic effect of
local hyperthermia during photo-irradiation may be of great importance for good
antitumor effect of PDT with chlorin e6 on melanoma skin metastases.
In the treatment of numerous malignant tumors of the skin, PDT procedures may
be repeated to achieve the desired effect. For instance, Robinson et al. (34)
described the treatment of two patients with Bowen's disease with an overall
number of tumors of more than 500. Five treatments provided complete cure (6-
month follow up). We had a case of PDT for a female patient with skin metastases
from pigmented melanoma, 150 metastases in total. The patient received five PDT
courses during a year and a half. No new skin metastases from melanoma were
detected in the patient within 2 years after the treatment.
It is noteworthy that our study is limited with only 14 cases because of the relatively
low incidence of isolated melanoma skin metastases without distant metastases
into internal organs. The median survival for patients with melanoma may vary
between 218 days and 1977 days (35, 36). The median survival of our patients
was 883 days. In this situation, it is difficult to determine the PDT influence on the
general survival of the patients, with only skin melanoma metastases as most of
the patients' mortality was attributable to metastatic tumors in other organs.
Akimov et al. (37) achieved the total response only in 56% cases after
chemotherapy (dacarbazine+cisplatin+BCNU+tamoxifen) in combination with laser
coagulation for disseminated skin melanoma (16 patients). Using only PDT, we
saw a complete response in eight cases of disseminated skin melanoma after one
PDT course and in another six cases after two to five PDT courses without severe
toxic side effects.
In conclusion, PDT with chlorin e6 for skin metastases from pigmented melanoma
is well tolerated and effective, especially in cases of isolated melanoma skin
metastases. Further clinical investigation of PDT with chlorin e6 is warranted to
define the place of PDT in the treatment of skin metastases of melanoma.
Acknowledgements
This study was supported by a grant from Belarus' Ministry of Health Care. We
thank all physicians of N.N. Alexandrov Research Institute of Oncology and
Medical Radiology, who participated in this study. Without their help, this research
could not have been conducted. We thank Mr. A. Zhitomirsky and Ms. J. Skapik for
editing this paper and Mr. S. Rubtsov for computer technical assistance. |
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