[Radiation-induced neuropathies: collateral damage of improved cancer prognosis]. / Neuropathies post-radiques: un dommage collatéral chez les patients cancéreux long-survivants.

INTRODUCTION: Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system. STATE OF THE ART: Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation. PERSPECTIVES AND CONCLUSION: The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and inflammation. A phase III trial evaluating the association of pentoxifylline, tocopherol and clodronate (PENTOCLO, NCT01291433) in radiation-induced neuropathies is now recruiting.

Is radiation-induced arteriopathy in long-term breast cancer survivors an underdiagnosed situation?: Critical and pragmatic review of available literature.

PURPOSE: Although considered exceptional, radiation-induced arteriopathy in long-term breast cancer survivors involves three main arterial domains in the irradiated volume, namely axillary-subclavian, coronary, and carotid. Stenosis of medium-large arteries is caused by "accelerated" atherosclerosis, particularly beyond 10 years after long-forgotten radiotherapy. The present review aims at summarizing what is known about arteriopathy, as well as the state of the art in terms of diagnosis and therapeutic management. DIAGNOSIS: Pauci-symptomatic over years, the usual clinical presentation of arteriopathy involves arm pain with coldness due to subacute or critical ischemia (arterial occlusion), wrongly attributed to an exclusive neurological disorder, and more rarely transient ischemic accident or angina. Evaluation of the supra-aortic trunks by computed tomography and/or magnetic resonance angiography visualizes artery lesions, while Doppler ultrasonography in expert hands assesses diagnosis and downstream functional impact. In severe cases, more invasive angiography directly visualizes long irregular arterial stenosis (full-field radiotherapy), allowing accurate prognosis and treatment. MANAGEMENT: Requires early diagnosis to enable initiation of medical treatment that increases blood flow (aspirin) as soon as moderate stenosis is detected, combined with correction of vascular risk factors. In intermediate cases, these therapeutic measures are completed by revascularization strategies using transluminal angioplasty-stenting (wall thickness). Antifibrotic treatment is useful in advanced cases with combined radiation injuries. CONCLUSION: In follow-up of long-term breast cancer survivors with node irradiation, myocardial infarction is treated even if radiotherapy is forgotten, while recognition and diagnosis of chronic arm ischemia due to subclavian artery stenosis needs to be improved for appropriate therapeutic management.

[Post-operative fibrosis: pathophysiological aspects and therapeutical perspectives]. / Fibrose postopératoire : aspects physiopathologiques et perspectives thérapeutiques.

Postoperative fibrosis (POF) is a rare, localized, and irreversible delayed effect of surgery, described in numerous tissues and organs. Is this fibrotic process amenable to therapeutic intervention? A synthesis of various clinical and histopathological aspects, and of cellular and molecular process regulation is described. In summary, there exists a prefibrotic chronic inflammatory phase, a constituted and cellular phase, and lastly a matricial densification and remodelling phase. The respective phases and the roles played over time by the main protagonists, namely myofibroblasts, extracellular matrix and growth factor (TGFbeta1) are clarified. Understanding the mechanism of POF leads logically to treatments derived from our knowledge of the treatment of radiation-induced fibrosis: anti-inflammatory drugs help in the prefibrotic phase, pentoxifylline-tocopherol combination (PE) in the organized fibrotic phase, and pentoclo (PE-clodronate) in the late fibronecrotic phase. Randomized trials are necessary to validate the preliminary results of phase II trials.

Striking regression of chronic radiotherapy damage in a clinical trial of combined pentoxifylline and tocopherol.

PURPOSE: Radiation-induced fibrosis (RIF) remains the most morbid complication of radiotherapy because of the absence of spontaneous regression and the difficulty of patient management. RIF treatment with combined pentoxifylline (PTX) and tocopherol (Vit E) was prompted by recent advances in cellular and molecular biology that have improved researchers' understanding of radiation-induced late-injury mechanisms and by the excellent results from our previous human and animal studies. PATIENTS AND METHODS: Forty-three patients (mean [+/- SD] age, 59 +/- 10 years) presenting with 50 symptomatic RIF areas involving the skin and underlying tissues were treated from April 1995 to September 1997. Patients had had radiotherapy for head and neck or breast cancer a mean period of 8.5 +/- 6.5 years previously. RIF developed in the first year after irradiation and gradually worsened, without spontaneous regression. The mean measurable surface area of RIF ([S]) at the time of this study ([S(0)]) was 42 +/- 34 cm(2). The initial Subjective Objective Medical management and Analytic (SOMA) injury evaluation score was 13.2 +/- 5.9 and included evidence of edema, plexitis, restricted movement, and local inflammatory signs. A combination of PTX (800 mg/d) and Vit E (1,000 IU/d) was administered orally for at least 6 months. RESULTS: Treatment was well tolerated. All assessable injuries exhibited continuous clinical regression and functional improvement. Mean RIF surface area and SOMA scores improved significantly (P <.0001) at 3 months ([S(3)], -39%; [SOMA(3)], -22%), 6 months ([S(6)], -53%; [SOMA(6)], -35%), and 12 months ([S(12)], -66%; [SOMA(12)], -48%), and mean linear dimensions ([D]) diminished from the start of the study ([D(0)], 6.5 +/- 2.5 cm) to the end of treatment 12 months later ([D(12)], 4 +/- 2 cm). At the time of the treatment, we did not attempt to achieve the maximum effect, and the study was continued. CONCLUSION: The PTX-Vit E combination reversed human chronic radiotherapy damage and, because no other treatment is presently available for RIF, should be considered as a therapeutic measure.

Combined radiation and chemotherapy for invasive transitional-cell carcinoma of the bladder: a prospective study.

PURPOSE: To improve the results obtained by cystectomy alone and to determine the possibilities of conservative treatment in invasive bladder cancer, we designed a prospective study using a combination of fluorouracil (5-FU) plus cisplatin and concomitant radiation therapy, followed by either cystectomy or additional chemoradiotherapy. PATIENTS AND METHODS: Fifty-four patients with stage T2 to T4 operable untreated invasive bladder cancer were entered onto the study. Treatment was begun in all patients by transurethral resection (TUR) and followed by the 5-FU-cisplatin combination with concomitant bifractionated split-course radiation therapy. A control cystoscopy was performed 6 weeks after completion of the neoadjuvant program. Patients with persistent tumor underwent cystectomy. Complete responders were treated by either additional chemoradiotherapy (group A) or cystectomy (group B). RESULTS: At control cystoscopy, 40 of 54 patients (74%) had a histologically documented complete response. Four responders developed recurrent pelvic disease after a mean follow-up time of 27 +/- 12 months (three in group A and one in group B). Metastatic disease, which developed in 16 patients, occurred more frequently in the nonresponders (71%) than in responders (15%). The disease-free survival rate at 3 years was 62%; it was significantly better in responders (77%) than in nonresponders (23%). There was no difference in survival between groups A and B. CONCLUSION: This neoadjuvant chemoradiotherapy combination, easy to implement and well tolerated even in elderly patients, provides a high complete response rate. It may prove to be effective in inoperable patients and may be proposed as conservative treatment in patients with a complete response to the initial course of chemoradiation.

[Uterus after irradiation]. / Utérus après irradiation.

Today, the good prognosis of girl's cancers raises the question of her future fertility. Several studies have focused on preservation of ovarian function, but the uterus, irradiated in childhood, is a crucial component to bear in mind because the somatic damages, in terms of endometrial and myometrial atrophy, scar fibrosis and hypovascularization, are negative factors for the establishment and maintenance of a pregnancy and for a convenient labour. Consequences for procreation are related to the morphologic uterine sequelae and its altered function: early miscarriages, abnormal placentation etc. In addition to some spontaneous pregnancies reported in literature, a few pregnancies, for women experiencing a premature iatrogenic ovarian failure due to mild irradiation, have been obtained after in vitro fertilization and oocyte donation with increased estrogen treatment. Recently, a real hope has surged in relation to the opportunity to reverse the radio-induced fibrosis and thus to obtain a better trophic uterus, using the antioxidant pathway. So, a treatment combining pentoxifylline 800 mg/d and tocopherol 1000 IU/d for 12 months allowed improvement of local uterine conditions such as endometrial thickness (x2), myometrial dimensions (x1.5) and uterine vascularization in all six sterile women studied, who have received high irradiation in childhood (>or=45 Gy). Moreover, two women mildly irradiated (#20 Gy) with endometrium resisting to physiological estrogen status, became spontaneously pregnant after using this combined treatment, and gave birth to healthy children. Further studies are in progress to assess, among other questions, the interest of this therapeutic direction.

Antifibrotic action of Cu/Zn SOD is mediated by TGF-beta1 repression and phenotypic reversion of myofibroblasts.

Skin fibrosis is characterized by the proliferation and accumulation of activated fibroblasts called myofibroblasts. They exhibit specific cytoskeletal differentiation, overexpress the fibrogenic cytokine TGF-beta1, synthesize excess extracellular matrix compounds and exhibit a depleted antioxidant metabolism. Recently, SOD was successfully used as an antifibrotic agent in vivo, thus challenging the postulate of established fibrosis irreversibility. We postulated that myofibroblasts could be a direct target for this therapeutic effect. To test this hypothesis, we used three-dimensional co-culture models of skin, in which specific phenotypes of normal fibroblasts versus myofibroblasts are retained. These 3-D models were treated with liposomal and carrier-free Cu/Zn SOD, and examined for their effects on cell number, cell death, and phenotypic differentiation. The results show that SOD did not induce myofibroblast cell death, whereas it significantly reduced TGF-beta1 expression, thus demonstrating that SOD might be proposed as a potent antagonist of this major fibrogenic growth factor. We also found that SOD significantly lowered the levels of the myofibroblast marker alpha-sm actin, of beta-actin, and of the extracellular matrix components alpha1(I) collagen and tenascin-C. In conclusion, our results suggest that SOD antifibrotic action occurred in vitro through the reversion of myofibroblasts into normal fibroblasts.

Prognostic value of in vitro uptake and retention of cytosine arabinoside in acute myelogenous leukemia.

In vitro uptake and retention of 3H-cytosine arabinoside (ara-C) was studied in 68 acute myelogenous leukemia (AML) patients (ten were studied twice) treated with a regimen containing conventional (54 patients) or high doses (24) of ara-C. Drug uptake and retention after four hours were measured following 30 minutes exposure to 1 and 50 micrograms/mL of ara-C. A good correlation was observed between high uptake in the acid soluble (AS) fraction (P less than .01), or high retention in the acid insoluble (Al) fraction (P less than .03) of 1 microgram, but not 50 micrograms, of the drug and obtainment of complete remission (CR) in patients treated with conventional doses of ara-C. Patients with a high percentage of ara-C retained in the AS fraction (greater than 26%) have a significantly longer CR duration than patients with a lower level of retention (P less than .02). In 17 patients who achieved a CR in spite of a low tritiated ara-C uptake, the clonogenic leukemic (CFU-L) cells were especially sensitive to drugs (15 of 17 v three of 11 among resisting patients).

TGF-beta1 and radiation fibrosis: a master switch and a specific therapeutic target?

Radiation fibrosis is a frequent sequel of therapeutic or accidental radiation overexposure in normal human tissues. One of the main fundamental problems yet unsolved in fibrotic tissues is the origin of the chronic activation of myofibroblasts within these tissues. It has been postulated that this chronic activation results from a continuous production of activating factors. In this context, fibrosis could be defined as a wound where continuous signals for tissue repair are emitted. Cytokines and growth factors probably play a central role in this process. Among them, transforming growth factor-beta1 (TGF-beta1) is considered as a master switch for the fibrotic program. This review discusses recent evidence on the critical role played by TGF-beta in the initiation, development, and persistence of radiation fibrosis. It summarizes the results concerning this factor after irradiation of various tissues and cells, with an emphasis on superficial fibrosis, including skin and subcutaneous tissues. Finally, recent data concerning the treatment of established fibrotic disorders of various etiology are presented, as well as the possible mechanisms involved in fibrosis regression, which show that the TGF-beta pathway may constitute a specific target for antifibrotic agents.

Chiasmal gliomas: results of irradiation management in 57 patients and review of literature.

Fifty-seven patients with optic gliomas, treated by megavoltage radiotherapy between May 1970 and March 1986, are retrospectively analyzed. The mean follow-up was 7.5 years (2.5-16.5). At presentation, 46% were under 10 years old, 40% had neurofibromatosis, and 51% had neurological and/or endocrinological signs. Twenty-one tumors (37%) were confined to the optic chiasm, and 36 tumors (63%) extended to the hypothalamus, the posterior optic tract, or the adjacent brain. Two among the 16 biopsy-proven tumors were high grade gliomas. Delivered tumor doses were 40 to 60 Gy in 5 to 7 weeks. Forty-nine patients were alive (five with tumor evolution) and eight had died (five from the tumor, one from cerebrovascular complication, two from intercurrent disease). Overall actuarial survival was 83.5% at 5 and 10 years. Control of the disease in 53 evaluables patients was: complete response in 8 (15%), partial response in 25 (46%), and no progression in 12 (22%). Progressive disease was observed in three patients and signs evocative of recurrence in five others. Stabilization of visual impairment or improvement of vision was recorded in 93% of patients who were evaluable. A critical review of the literature is presented and complications discussed. Radiotherapy seems thus effective in chiasmal gliomas and must be delivered in cases of rapidly developing symptoms visual, neurological, or endocrine.

The use of a specific hypofractionated radiation therapy regimen versus classical fractionation in the treatment of breast cancer: a randomized study of 230 patients.

An ongoing randomized study of a specific regimen of hypofractionated radiation therapy (IHF) versus classical or standard radiation therapy (IC) for breast cancer was begun in the Department of Radiation Therapy of the Necker Hospital, Paris France, in January 1982. Breast cancer patients entered into this study received either IC to deliver 45 Gy in 25 fractions over 33 days or a specific IHF regimen to deliver 23 Gy in 4 fractions over 17 days. As of June 1989, 525 patients had been entered into the study. The first 230 patients treated from 1982 through December 1984 had a minimum follow-up of 4 years (range: 4 to 7 years). Preliminary analysis of the results in these first 230 patients are presented. The distribution of patients in this initial group according to clinical staging, associated treatments, and pathological nodes is as follows: T1 = 22%, T2 = 61%, T3 + T4 = 17%, palpable nodes = 28%, inflammatory signs = 7%, surgical treatment = 79% (mastectomy = 35%, tumorectomy + Ir.192 = 44%), radiation alone + neoadjuvant chemotherapy = 21%, N+ = 50% of patients undergoing surgery. Loco-regional recurrences developed in 7% (9/125) of patients in the IHF group and in 5% (5/105) of patients in the IC group. Complications were minor. The addition of the percentage of each complication noted results in a total of 23% for the IHF group and 19% for the IC group (one patient could present several complications). As we had previously observed when comparing these two fractionation regimens in other studies with other tumors, these preliminary results showed no evident difference in the effectiveness and rate of complications whether IHF or IC was used to treat patients with breast cancer.

Iridium 192 plesiocurietherapy using silicone elastomer plates for extensive locally recurrent breast cancer following chest wall irradiation.

From July 1985 to October 1988, 11 patients with prior treatment for breast cancer, and presenting an isolated superficial widespread inoperable chest wall recurrence, underwent plesiocurietherapy for salvage. Most patients (91%) had had a mastectomy. The recurrences developed in tissue that had previously been irradiated to 45-55 Gy in three patients and 65 Gy in eight patients. Salvage was attempted using two or three courses of plesiocurietherapy at monthly intervals to decrease treatment complications. The position of the active sources was maintained parallel but slightly shifted at each application. A total dose of 60 Gy was delivered to a Reference Isodose (R.I.) located 2 to 4 mm under the skin surface. The guide system consisted of plastic tubes inserted at 1.5 cm intervals into flexible silicone plates that were applied to the skin surface to maintain the actives lines 0.5 cm above the skin surface. The high dose sleeves surrounding the actives lines (dose greater than 2 x R.I.) were contained within the thickness of the silicone plate. The mean surface treated was 480 cm2 (range 30-1030 cm2). Two patients had continued progression of the lesions within the treated volume during and after curietherapy and died rapidly of metastatic disease. Nine (89%) patients showed complete regression of treated lesions. But two patients developed a new recurrence outside the treated volume. Complications were acceptable: five patients experienced regressive moderate to severe radiation dermatitis and one had skin necrosis that healed in 2 months. These preliminary results have shown that even when tumor extension and previous treatment theorically counter-indicate further local therapy for locally recurrent breast cancer, it is possible to obtain immediate and, at times, lasting control of local disease using two or three courses of plesiocurietherapy with a source shift.

Striking regression of subcutaneous fibrosis induced by high doses of gamma rays using a combination of pentoxifylline and alpha-tocopherol: an experimental study.

PURPOSE: To establish a successful treatment of subcutaneous fibrosis developing after high doses of gamma rays, suitable for use in clinical practice. METHODS AND MATERIALS: We used an animal model of acute localized gamma irradiation simulating accidental overexposure in humans. Three groups of 5 Large White pigs were irradiated using a collimated 192Ir source to deliver a single dose of 160 Gy onto the skin surface (100%) of the outer side of the thigh. A well-defined block of necrosis developed within a few weeks which had healed after 26 weeks to leave a block of subcutaneous fibrosis involving skin and skeletal muscle. One experimental group of 5 pigs was dosed orally for 26 weeks starting 26 weeks after irradiation with 1600 mg/120 kg body weight of pentoxifylline (PTX) included in the reconstituted food during its fabrication, and another group of 5 was dosed orally for the same period with a daily dose of 1600 mg/120 kg body weight of PTX combined with 2000 IU/120 kg body weight of alpha-tocopherol. Five irradiated control pigs were given normal food only. Animals were assessed for changes in the density of the palpated fibrotic block and in the dimensions of the projected cutaneous surface. Depth of scar tissue was determined by ultrasound. Physical and sonographic findings were confirmed by autopsy 26 weeks after treatment started. The density, length, width, and depth of the block of fibrotic scar tissue, and the areas and volume of its projected cutaneous surface, were compared before treatment, 6 and 13 weeks thereafter, and at 26 weeks. RESULTS: The experimental animals exhibited no change in behavior and no abnormal clinical or anatomic signs. No modifications were observed in the block of fibrotic scar tissue of pigs dosed with PTX alone. However, significant softening and shrinking of this block were noted in the pigs dosed with PTX + alpha-tocopherol 13 weeks after treatment started and at autopsy, when mean regression was approximately 30% for length, approximately 50% for width and depth, and approximately 70% for area and volume. Histologic examination showed completely normal muscle and subcutaneous tissue surrounding the residual scar tissue. The 50% decrease in the linear dimensions of the scar tissue, were comparable to the results obtained in our previous clinical studies, and were highly significant compared to the clinical and autopsy results for the controls. Histologic examination of the residual scar tissue revealed tissue which was more homogenous and less cellular and inflammatory than in control and PTX-dosed pigs. The tissular and cellular immunolocalization of tumor necrosis factor alpha (TNFalpha) was similar in the residual fibrotic tissues of all three groups of pigs, whereas the immunostaining of transforming growth factor beta-1(TGFbeta-1) diminished much more in the residual fibrotic scar tissue of the PTX + alpha-tocopherol-dosed pigs than in the two other groups. CONCLUSIONS: The present results showed a striking regression of the subcutaneous fibrotic scar tissue that develops as a consequence of high doses of gamma rays.

Split course interstitial brachytherapy with a source shift: the results of a new technique for salvage irradiation in recurrent inoperable cervical lymphadenopathy greater than or equal to 4 cm diameter in 23 patients.

Between June 1981 and December 1986, 23 patients with prior irradiation of the neck for epithelial ENT tumors underwent salvage irradiation for isolated recurrent inoperable cervical lymphadenopathy greater than or equal to 4 cm. The initial irradiation had delivered 45-80 Gy to the cervical lymph nodes. Split course interstitial brachytherapy was used with a source shift in an attempt to decrease treatment complications. The first and second course of the split course implants delivered 35 Gy and 30 Gy at a 1 month interval. The active lines of the second implant were placed parallel to and in between the position of the lines of the first implant. Three patients did not receive the second implant (one death, one disease evolution, one necrosis). For the patient who died between the first and second implants the local control rate could not be determined. The immediate overall local control rate was 73% (16/22) with a later recurrence rate of 62% (10/16), but only in three cases was recurrence within the treated volume (19%-3/16). The local control rate was better (3/9) if the initial lymphadenopathy was greater than or equal to 4 cm less than or equal to 6 cm but worse (3/13) in those with initial lymphadenopathy greater than 6 cm. Survival of these patients overall was poor with 26% survival at 1 year and 13% at 2 years. Tolerance overall was acceptable with tissue necrosis occurring in 36.5% of cases including those with initial skin involvement. If these cases were excluded the necrosis rate was only 15.5%. In this patient population with inoperable recurrent cervical lymphadenopathy in whom a further dose of external irradiation is not possible interstitial brachytherapy should be considered. Our technique of implantation, split over two sessions with a source shift, is practicable with an acceptable toxicity. It may be used even after high dose external beam irradiation and in large volumes of disease, and it gives better results than classical brachytherapy.

Split course interstitial brachytherapy with a source shift: the results of a new iridium implant technique versus single course implants for salvage irradiation of base of tongue cancers in 55 patients.

Between January 1973 and December 1984, 55 patients with prior irradiation of the oropharynx underwent salvage irradiation for recurrent (26 patients) or second cancers (29 patients) of the base of tongue. The initial irradiation had delivered from 45 to 80 Gy to the base of tongue. One of two techniques of Iridium implantation was used for salvage. Single course implants, delivering 60 Gy, were used until June 1981 in a total of 31 patients. After June 1981, split course implants with a source shift were used in 24 patients in the hope of decreasing treatment complications. The first and second course of the split course implants delivered 35 and 30 Gy, respectively, at a 1-month interval. The active lines of the second implant were placed parallel to and between the position of the lines of the first implant. This shift in the source position resulted in a more uniform dose within the treated volume with a 60% reduction in the high dose sleeves. The overall 3-year survival was 19% (28% T less than or equal to 3 cm). The overall local failure rate was 45.5% (25/55). The difference between the local failure rate after single course implants (52%) and after split course implants (37.5%) was not statistically significative. The response observed after the first course of a split course implant proved to be a reliable indication of the probability of achieving local control after a full course of treatment: 2/14 failures (14%) if the response was greater than or equal to 75% versus 7/10 (70%) if the response was less than 75% (p less than 0.01). The only complication noted in the 40 patients achieving immediate local control after either implant technique was mucosal necrosis. The introduction of split course implants was followed by a two and a half fold decrease in the incidence of necrosis: 43% (9/21) in the single course group and 16% (3/19) in the split course group (p = 0.05). Interstitial brachytherapy offers an effective and reasonable option for salvage therapy in patients with recurrent and second cancers occurring in the base of tongue even when the tumor arises in a zone that has previously received high dose irradiation. The use of split course implants with a shift in the position of the active lines at the time of the second implant significantly decreases the risk of radionecrosis.

Successful treatment of radiation-induced fibrosis using Cu/Zn-SOD and Mn-SOD: an experimental study.

PURPOSE: To establish how far liposomal copper/zinc superoxide dismutase (Cu/Zn-SOD) and manganese superoxide dismutase (Mn-SOD), respectively, reduce radiation-induced fibrosis (RIF), using a well-characterized pig model of RIF permitting the design of a controlled laboratory experiment. METHODS AND MATERIALS: In this model of acute localized gamma irradiation simulating accidental overexposure in humans, three groups of five large white pigs were irradiated using a collimated 192Ir source to deliver a single dose of 160 Gy onto the skin surface (100%) of the outer side of the thigh. A well-defined block of subcutaneous fibrosis involving skin and skeletal muscle developed 6 months after irradiation. One experimental group of five pigs was then injected i.m. with 10 mg/10 kg b.wt. of Cu/Zn-SOD, twice a week for 3 weeks, and another experimental group of five was injected with 10 mg/10 kg b.wt. of Mn-SOD, three times a week for 3 weeks. Five irradiated control pigs were injected with physiological serum. Animals were assessed for changes in the density of the palpated fibrotic block and in the dimensions of the projected cutaneous surface. Block depth was determined by ultrasound. Physical and sonographic findings were confirmed by autopsy 12-14 weeks after completing SOD injections. The density, length, width, and depth of the fibrotic block, and the areas and volume of its projected cutaneous surface were compared before treatment, 1, 3, and 6 weeks thereafter, and at autopsy, 12-14 weeks after treatment ended. RESULTS: The experimental animals exhibited no change in behavior and no abnormal clinical or anatomic signs. Whether they were given Cu/Zn- or Mn-SOD, significant and roughly equivalent softening and shrinking of the fibrotic block were noted in all treated animals between the first week after treatment ended and autopsy, when mean regression was 45% for length and width, 30% for depth, and 70% for area and volume. Histologic examination showed completely normal muscle and subcutaneous tissue surrounding the residual scar. This replacement of scar tissue by normal tissue in experimental animals and the 50% decrease in the linear dimensions of the scar were comparable to the results obtained in previous clinical studies and highly significant compared to the clinical and autopsy results for the control animals. CONCLUSIONS: Our results are striking and comparable to the results obtained in our previous clinical study after liposomal Cu/Zn-SOD treatment. To our knowledge, this is the first time that two agents have been shown to reverse the radiation-induced fibrotic process in experimental animals and to permit the regeneration of normal tissue in a zone of well-established postirradiation fibrosis.

Abnormal phenotype of cultured fibroblasts in human skin with chronic radiotherapy damage.

PURPOSE: The pathophysiological aspects of radiation-induced fibrosis (RIF) have not been well characterized. We therefore cultured human fibroblasts from samples of skin with RIF to investigate the long-term effects of therapeutic irradiation. MATERIALS AND METHODS: Biopsies of normal and RIF skin were obtained from patients previously irradiated for cancer, without recurrence. Cells were extracted from dermis samples by the outgrowth technique, seeded as monolayers and cultured at confluence. Enzyme activities and proteins were assayed, RNA was isolated and Northern blot analysis was performed on surviving cells between passages 2 and 5. RESULTS: RIF cell cultures displayed heterogeneous fibroblasts populations. The initial outgrowth consisted of one-third small cells that floated rapidly, one-third spindle-shaped cells migrating far from the explant to form islets and one-third large pleiomorphic cells. In subsequent subcultures, surviving cells exhibited either myofibroblastic characteristics with a normal proliferative capacity or senescent morphology with a reduced proliferative capacity. These RIF cells had a brief finite lifespan, with dramatically reduced growth rate during their initial outgrowth and the following passages. Study of the antioxidant metabolism showed that Mn superoxide dismutase and catalase activities were significantly weaker in surviving RIF cells than healthy fibroblasts. These exhausted RIF cells exhibited no overexpression of transforming growth factor beta or tissue inhibitor of metalloproteinase. CONCLUSION: Irradiation may lead to apparently contradictory effects such as fibrosis and necrosis in clinical practice. In cell culture, we observed two main cellular phenotypes which may be related to both processes, i.e. myofibroblast-like cells and fibrocyte-like cells. These two phenotypes may represent two steps in the differentiation induced as a long-term effect of therapeutic irradiation of the skin. Cell culture probably accelerates the induction of the terminal differentiation in RIF fibroblasts.

Cu/Zn superoxide dismutase modulates phenotypic changes in cultured fibroblasts from human skin with chronic radiotherapy damage.

PURPOSE: As we previously observed that bovine liposomal Cu/Zn SOD (LipSOD) reduces cutaneous radiation-induced fibrosis (RIF) in human therapeutic assays the mechanisms involved were investigated here by an in vitro study of the LipSOD effects on cellular antioxidant metabolism and regulation of matrix degradation. METHODS: Primary cultures of human fibroblasts harvested from normal or RIF skin were treated with various doses of LipSOD. Catalase, Cu/Zn and Mn SOD endogenous cell enzyme activities and protein amounts were assayed by polyacrylamide gel electrophoresis and western blotting. Gene expressions of tissue inhibitor of metalloproteinases (TIMP) and TGF-beta1 was investigated by northern blot analysis. RESULTS: A deficiency of endogenous Mn SOD, considered to favour cell proliferation, was observed in cultured RIF cell. The present study showed that bovine Cu/Zn SOD entered the cells. Exposure to LipSOD (a) enhanced endogenous Mn SOD activity and protein level, without changes of endogenous Cu/Zn SOD and catalase, and (b) significantly reduced TIMP and TGF-beta1 gene expression, in RIF cells. No changes in these parameters were noted in treated control skin fibroblasts. CONCLUSION: Modulation of RIF skin fibroblasts by LipSOD seems effective via indirect endogenous Mn SOD activation, which might explain the cell phenotype reversion observed. TIMP reduction accounts for the elimination of collagenase activity inhibition and the subsequent digestion of excess extracellular matrix deposition, as well as RIF reversibility in vivo. The reduction of TGF-beta1 expression might explain the breaking of maintaining fibrotic cell activation connected with this growth factor.

Successful treatment of radiation-induced fibrosis using liposomal Cu/Zn superoxide dismutase: clinical trial.

Based on experimental and clinical evidence indicating that the anti-oxidant agent liposomal Cu/Zn superoxide dismutase (Lipsod) is an effective anti-inflammatory drug and possibly might be effective in reducing late radiation-induced tissue injury, a clinical trial using Lipsod to treat long-standing radiation-induced fibrosis (RIF) was begun at the Necker Hospital, Paris in May 1984. Thirty-four patients presenting 42 distinct palpable zones of RIF involving the skin and underlying tissues were treated from May 1984 to January 1986 and followed for an average of 5 years (range, 14-89 months). Lipsod was administered over 3 weeks in twice weekly i.m. injections of 5 mg for a total of 30 mg. Patients underwent two physical examinations by independent physicians at each check-up. Parameters noted included determination of the density of the palpated fibrotic block and the dimensions of the projected cutaneous surface. The extent of change in the fibrotic zone was expressed as the ratio of the sum of the dimensions (L + W) and the ratio of the uncorrected areas (L x W) of the projected cutaneous surface before and after treatment. Changes in density were noted and scored. All patients showed some clinical regression of fibrosis. In most patients, clinically assessable regression begun during the third week of treatment and was maximum by 2 months. The mean decreases in the linear dimensions (L + W) and in the area (L x W) of the projected cutaneous surface were 41 +/- 30% and 57 +/- 26%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative radiation therapy for cervical lymph node metastases from an occult squamous cell carcinoma.

One hundred thirteen patients with cervical metastases from a squamous cell carcinoma and no evidence of the primary tumor were treated for cure by surgery and routine large-field postoperative irradiation. Patients were staged according to the 1987 American Joint Committee on Cancer (AJCC) classification. There were 24 N1, 54 N2, 29 N3, and 6 Nx lesions. One hundred four patients underwent cervical lymph node dissection and 9 had adenectomy. All patients received postoperative external beam therapy to the entire naso-oro-pharyngo-larynx and all cervical lymphatics. The overall nodal failure rate was 13.7%. Nodal failure was significantly correlated with N staging (P = .01) and with the number of histologically involved nodes (P = .05). NOdal failure was 21% when nodes were initially fixed versus 7.5% when they were not (P = .07) and 18% when there was extracapsular spread versus 4.3% when the capsule was intact (P = .11). Eleven patients (9.7%) developed a subsequent primary lesion. In 3 patients (2.6%), this primary was located in the previously irradiated area and, in 2 cases, under the anterior block of lateral fields. Metastases occurred in 18 patients (16%). The five-year overall survival rate was 38%. Survival was correlated with N staging (P less than .02), nodal fixation (P = .05), extracapsular spread (P = .01) and loosely with the number of histologically involved nodes (P = .08). On the contrary, histological differentiation did not influence the local control rate, nor the development of metastases or subsequent primary lesions. Large-field prophylactic radiation therapy appears to be effective in preventing the emergence of initially occult primary lesions. However, control of disease in the neck and survival remain disappointing in patients with advanced nodal disease, even after combined surgery and radiation therapy.