Comparison of clinical outcomes between carbon ion radiotherapy and X-ray radiotherapy for reirradiation in locoregional recurrence of rectal cancer

Carbon ion radiotherapy (CIRT) has garnered interest for the treatment of locoregional rectal cancer recurrence. No study has compared CIRT and X-ray radiotherapy (XRT) for reirradiation (reRT) in such cases. We analyzed and compared the clinical outcomes such as local control, overall survival, and late toxicity rate between CIRT and XRT, for treating locoregional rectal cancer recurrence. Patients with rectal cancer who received reRT to the pelvis by CIRT or XRT from March 2005 to July 2019 were included. The CIRT treatment schedule was 70.4 Gy (relative biological effectiveness) in 16 fractions. For the XRT group, the median reRT dose was 50 Gy (range 25-62.5 Gy) with a median of 25 fractions (range 3-33). Thirty-five and 31 patients received CIRT and XRT, respectively. Tumour and treatment characteristics such as recurrence location and chemotherapy treatment differed between the two groups. CIRT showed better control of local recurrence (adjusted hazard ratio [HR] 0.17; p = 0.002), better overall survival (HR 0.30; p = 0.004), and lower severe late toxicity rate (HR 0.15; p = 0.015) than XRT. CIRT was effective for treating locoregional rectal cancer recurrence, with high rates of local control and survival, and a low late severe toxicity rate.

Field size effects on DNA damage and proliferation in normal human cell populations irradiated with X-ray microbeams

To clarify the health risks of internal radiation exposure, it is important to investigate the radiological effects of local exposure at cell levels from radioactive materials taken up by organs. Focusing on the response of cell populations post-irradiation, X-ray microbeams are very effective at reproducing the effects of local exposure within an internal exposure in vitro. The present study aims to clarify the effects of local exposure by investigating the response of normal human cell (MRC-5) populations irradiated with X-ray microbeams of different beam sizes to DNA damage. The populations of MRC-5 were locally irradiated with X-ray microbeams of 1 Gy at 0.02-1.89 mm2 field sizes, and analyzed whether the number of 53BP1 foci as DSB (DNA double strand break) per cell changed with the field size. We found that even at the same dose, the number of DSB per cell increased depending on the X-irradiated field size on the cell population. This result indicated that DNA damage repair of X-irradiated cells might be enhanced in small size fields surrounded by non-irradiated cells. This study suggests that X-irradiated cells received some signal (a rescue signal) from surrounding non-irradiated cells may be involved in the response of cell populations post-irradiation.

Technical advances in x-ray microbeam radiation therapy

In the last 25 years microbeam radiation therapy (MRT) has emerged as a promising alternative to conventional radiation therapy at large, third generation synchrotrons. In MRT, a multi-slit collimator modulates a kilovoltage x-ray beam on a micrometer scale, creating peak dose areas with unconventionally high doses of several hundred Grays separated by low dose valley regions, where the dose remains well below the tissue tolerance level. Pre-clinical evidence demonstrates that such beam geometries lead to substantially reduced damage to normal tissue at equal tumour control rates and hence drastically increase the therapeutic window. Although the mechanisms behind MRT are still to be elucidated, previous studies indicate that immune response, tumour microenvironment, and the microvasculature may play a crucial role. Beyond tumour therapy, MRT has also been suggested as a microsurgical tool in neurological disorders and as a primer for drug delivery. The physical properties of MRT demand innovative medical physics and engineering solutions for safe treatment delivery. This article reviews technical developments in MRT and discusses existing solutions for dosimetric validation, reliable treatment planning and safety. Instrumentation at synchrotron facilities, including beam production, collimators and patient positioning systems, is also discussed. Specific solutions reviewed in this article include: dosimetry techniques that can cope with high spatial resolution, low photon energies and extremely high dose rates of up to 15 000 Gy s-1, dose calculation algorithms-apart from pure Monte Carlo Simulations-to overcome the challenge of small voxel sizes and a wide dynamic dose-range, and the use of dose-enhancing nanoparticles to combat the limited penetrability of a kilovoltage energy spectrum. Finally, concepts for alternative compact microbeam sources are presented, such as inverse Compton scattering set-ups and carbon nanotube x-ray tubes, that may facilitate the transfer of MRT into a hospital-based clinical environment. Intensive research in recent years has resulted in practical solutions to most of the technical challenges in MRT. Treatment planning, dosimetry and patient safety systems at synchrotrons have matured to a point that first veterinary and clinical studies in MRT are within reach. Should these studies confirm the promising results of pre-clinical studies, the authors are confident that MRT will become an effective new radiotherapy option for certain patients.

Bcl2-Expressing Quiescent Type B Neural Stem Cells in the Ventricular-Subventricular Zone Are Resistant to Concurrent Temozolomide/X-Irradiation

The ventricular-subventricular zone (V-SVZ) of the mammalian brain is a site of adult neurogenesis. Within the V-SVZ reside type B neural stem cells (NSCs) and type A neuroblasts. The V-SVZ is also a primary site for very aggressive glioblastoma (GBM). Standard-of-care therapy for GBM consists of safe maximum resection, concurrent temozolomide (TMZ), and X-irradiation (XRT), followed by adjuvant TMZ therapy. The question of how this therapy impacts neurogenesis is not well understood and is of fundamental importance as normal tissue tolerance is a limiting factor. Here, we studied the effects of concurrent TMZ/XRT followed by adjuvant TMZ on type B stem cells and type A neuroblasts of the V-SVZ in C57BL/6 mice. We found that chemoradiation induced an apoptotic response in type A neuroblasts, as marked by cleavage of caspase 3, but not in NSCs, and that A cells within the V-SVZ were repopulated given sufficient recovery time. 53BP1 foci formation and resolution was used to assess the repair of DNA double-strand breaks. Remarkably, the repair was the same in type B and type A cells. While Bax expression was the same for type A or B cells, antiapoptotic Bcl2 and Mcl1 expression was significantly greater in NSCs. Thus, the resistance of type B NSCs to TMZ/XRT appears to be due, in part, to high basal expression of antiapoptotic proteins compared with type A cells. This preclinical research, demonstrating that murine NSCs residing in the V-SVZ are tolerant of standard chemoradiation therapy, supports a dose escalation strategy for treatment of GBM. Stem Cells 2019;37:1629-1639.

Effects of Synchrotron X-Ray Micro-beam Irradiation on Normal Mouse Ear Pinnae

PURPOSE

To analyze the effects of micro-beam irradiation (MBI) on the normal tissues of the mouse ear.

METHODS AND MATERIALS

Normal mouse ears are a unique model, which in addition to skin contain striated muscles, cartilage, blood and lymphatic vessels, and few hair follicles. This renders the mouse ear an excellent model for complex tissue studies. The ears of C57BL6 mice were exposed to MBI (50-μm-wide micro-beams, spaced 200 μm between centers) with peak entrance doses of 200, 400, or 800 Gy (at ultra-high dose rates). Tissue samples were examined histopathologically, with conventional light and electron microscopy, at 2, 7, 15, 30, and 240 days after irradiation (dpi). Sham-irradiated animals acted as controls.

RESULTS

Only an entrance dose of 800 Gy caused a significant increase in the thickness of both epidermal and dermal ear compartments seen from 15 to 30 dpi; the number of sebaceous glands was significantly reduced by 30 dpi. The numbers of apoptotic bodies and infiltrating leukocytes peaked between 15 and 30 dpi. Lymphatic vessels were prominently enlarged at 15 up to 240 dpi. Sarcomere lesions in striated muscle were observed after all doses, starting from 2 dpi; scar tissue within individual beam paths remained visible up to 240 dpi. Cartilage and blood vessel changes remained histologically inconspicuous.

CONCLUSIONS

Normal tissues such as skin, cartilage, and blood and lymphatic vessels are highly tolerant to MBI after entrance doses up to 400 Gy. The striated muscles appeared to be the most sensitive to MBI. Those findings should be taken into consideration in future micro-beam radiation therapy treatment schedules.

Neurobehavioral radiation mitigation to standard brain cancer therapy regimens by Mn(III) n-butoxyethylpyridylporphyrin-based redox modifier

Combinations of radiotherapy (RT) and chemotherapy have shown efficacy toward brain tumors. However, therapy-induced oxidative stress can damage normal brain tissue, resulting in both progressive neurocognitive loss and diminished quality of life. We have recently shown that MnTnBuOE-2-PyP(5+) (Mn(III)meso-tetrakis(N-n-butoxyethylpyridinium -2-yl)porphyrin) rescued RT-induced white matter damage in cranially-irradiated mice. Radiotherapy is not used in isolation for treatment of brain tumors; temozolomide is the standard-of-care for adult glioblastoma, whereas cisplatin is often used for treatment of pediatric brain tumors. Therefore, we evaluated the brain radiation mitigation ability of MnTnBuOE-2-PyP(5+) after either temozolomide or cisplatin was used singly or in combination with 10 Gy RT. MnTnBuOE-2-PyP(5+) accumulated in brains at low nanomolar levels. Histological and neurobehavioral testing showed a drastic decrease (1) of axon density in the corpus callosum and (2) rotorod and running wheel performance in the RT only treatment group, respectively. MnTnBuOE-2-PyP(5+) completely rescued this phenotype in irradiated animals. In the temozolomide groups, temozolomide/ RT treatment resulted in further decreased rotorod responses over RT alone. Again, MnTnBuOE-2-PyP(5+) treatment rescued the negative effects of both temozolomide ± RT on rotorod performance. While the cisplatin-treated groups did not give similar results as the temozolomide groups, inclusion of MnTnBuOE-2-PyP(5+) did not negatively affect rotorod performance. Additionally, MnTnBuOE-2-PyP(5+) sensitized glioblastomas to either RT ± temozolomide in flank tumor models. Mice treated with both MnTnBuOE-2-PyP(5+) and radio-/chemo-therapy herein demonstrated brain radiation mitigation. MnTnBuOE-2-PyP(5+) may well serve as a normal tissue radio-/chemo-mitigator adjuvant therapy to standard brain cancer treatment regimens. Environ. Mol. Mutagen. 57:372-381, 2016. © 2016 Wiley Periodicals, Inc.

Relative biological effectiveness of carbon ions for tumor control, acute skin damage and late radiation-induced fibrosis in a mouse model

BACKGROUND

The aim of the present study was to compare the biological effectiveness of carbon ions relative to x-rays between tumor control, acute skin reaction and late RIF of CDF1 mice.

MATERIAL AND METHODS

CDF1 mice with a C3H mouse mammary carcinoma implanted subcutaneously on the foot of the right hind limb were irradiated with single fractions of either photons, or (12)C ions using a 30-mm spread-out Bragg peak. The endpoint of the study was local control (no tumor recurrence within 90 days). For the acute skin reaction, non-tumor bearing CDF1 mice were irradiated with a comparable radiation scheme, and monitored for acute skin damage between Day 7 and 40. Late RIF was assessed in the irradiated mice.

RESULTS

The TCD50 (dose producing tumor control in 50% of mice) values with 95% confidence interval were 29.7 (25.4-34.8) Gy for C ions and 43.9 (39.2-49.2) Gy for photons, with a corresponding Relative biological effectiveness (RBE) value of 1.48 (1.28-1.72). For acute skin damage the MDD50 (dose to produce moist desquamation in 50% of mice) values with 95% confidence interval were 26.3 (23.0-30.1) Gy for C ions and 35.8 (32.9-39.0) Gy for photons, resulting in a RBE of 1.36 (1.20-1.54). For late radiation-induced fibrosis the FD50 (dose to produce severe fibrosis in 50% of mice) values with 95% confidence interval were 26.5 (23.1-30.3) Gy for carbon ions and 39.8 (37.8-41.8) Gy for photons, with a RBE of 1.50 (1.33-1.69).

CONCLUSION

The observed RBE values were very similar for tumor response, acute skin damage and late RIF when irradiated with large doses of high- linear energy transfer (LET) carbon ions. This study adds information to the variation in biological effectiveness in different tumor and normal tissue models.

Comparison of adverse effects of proton and X-ray chemoradiotherapy for esophageal cancer using an adaptive dose-volume histogram analysis

Cardiopulmonary late toxicity is of concern in concurrent chemoradiotherapy (CCRT) for esophageal cancer. The aim of this study was to examine the benefit of proton beam therapy (PBT) using clinical data and adaptive dose-volume histogram (DVH) analysis. The subjects were 44 patients with esophageal cancer who underwent definitive CCRT using X-rays (n = 19) or protons (n = 25). Experimental recalculation using protons was performed for the patient actually treated with X-rays, and vice versa. Target coverage and dose constraints of normal tissues were conserved. Lung V5-V20, mean lung dose (MLD), and heart V30-V50 were compared for risk organ doses between experimental plans and actual treatment plans. Potential toxicity was estimated using protons in patients actually treated with X-rays, and vice versa. Pulmonary events of Grade ≥2 occurred in 8/44 cases (18%), and cardiac events were seen in 11 cases (25%). Risk organ doses in patients with events of Grade ≥2 were significantly higher than for those with events of Grade ≤1. Risk organ doses were lower in proton plans compared with X-ray plans. All patients suffering toxicity who were treated with X-rays (n = 13) had reduced predicted doses in lung and heart using protons, while doses in all patients treated with protons (n = 24) with toxicity of Grade ≤1 had worsened predicted toxicity with X-rays. Analysis of normal tissue complication probability showed a potential reduction in toxicity by using proton beams. Irradiation dose, volume and adverse effects on the heart and lung can be reduced using protons. Thus, PBT is a promising treatment modality for the management of esophageal cancer.

Grenz ray therapy in the new millennium: still a valid treatment option?

Grenz ray therapy has declined in the United States during the past several decades with respect to availability, use, and resident training. However, it remains a simple, affordable, and effective option for managing several refractory dermatoses, especially psoriasis, hand eczema, and allergic contact dermatitis. Though high-dose grenz irradiation has been associated with the development of nonmelanoma skin cancers, grenz ray therapy is considered a safe treatment modality when administered according to the guidelines recommended herein. We review the value of grenz irradiation in contemporary dermatology.

Efficacy and patient perception of Grenz ray therapy in the treatment of dermatoses refractory to other medical therapy

BACKGROUND

Grenz ray therapy (GRT) has been used to treat dermatoses refractory to other therapy. Patient's assessments to GRT alone have not been previously reported.

OBJECTIVE

(1) To report the patterns of use of GRT at our center over a 10-year period and evaluate the efficacy of GRT in treating recalcitrant skin conditions, (2) to evaluate patient perceptions about GRT, and (3) to evaluate whether patients felt this form of treatment was worthwhile.

METHOD

Cross-sectional survey by mailed questionnaire to patients treated with GRT from 1990 to 2001.

RESULTS

Of 351 patients treated with GRT from 1990 to 2001, 98 (28%) returned the questionnaire; 64% reported decreased severity or clearing of disease (p = .003), and 63% reported decreased or no discomfort (p = .006) 3 months following treatment. Overall, 54% said GRT was worthwhile, and 53% would choose it again; 40% reported mild side effects. Number of treatments (p = .2) or total dose (p = .25) were not significantly different among responders to GRT and nonresponders to GRT. In a subgroup of treated patients with a diagnosis of contact dermatitis (94% with hand dermatitis), 64% felt GRT was worthwhile and 77% indicated that they would choose this therapy again if needed.

CONCLUSIONS

Many patients treated with GRT for recalcitrant dermatitis reported that this treatment was an effective therapy in decreasing the discomfort and severity of their skin condition. Overall, just more than half of treated patients believed GRT was a worthwhile therapy that they would use again.

Prospects for microbeam radiation therapy of brain tumours in children to reduce neurological sequelae

Microbeam radiation therapy (MRT), a form of experimental radiosurgery of tumours using multiple parallel, planar, micrometres-wide, synchrotron-generated X-ray beams ('microbeams'), can safely deliver radiation doses to contiguous normal animal tissues that are much higher than the maximum doses tolerated by the same normal tissues of animals or patients from any standard millimetres-wide radiosurgical beam. An array of parallel microbeams, even in doses that cause little damage to radiosensitive developing tissues, for example, the chick chorioallantoic membrane, can inhibit growth or ablate some transplanted malignant tumours in rodents. The cerebella of 100 normal 20 to 38g suckling Sprague-Dawley rat pups and of 13 normal 5 to 12kg weanling Yorkshire piglets were irradiated with an array of parallel, synchrotron-wiggler-generated X-ray microbeams in doses overlapping the MRT-relevant range (about 50-600Gy) using the ID17 wiggler beamline tangential to the 6GeV electron synchrotron ring at the European Synchrotron Radiation Facility in Grenoble, France. Subsequent favourable development of most animals over at least 1 year suggests that MRT might be used to treat children's brain tumours with less risk to the development of the central nervous system than is presently the case when using wider beams.

Treatment of benign diseases with megavoltage X-ray beams: is there a risk for gonadal damage?

AIMS

To measure the testicular and ovarian doses and to assess the risk for gonadal damage to patients treated with megavoltage X-ray beams for benign diseases.

MATERIALS AND METHODS

Radiation therapy of benign diseases was simulated on an anthropomorphic phantom with a 6MV photon beam. The gonadal dose was calculated during the irradiation of heterotopic ossification, liver and vertebra haemangiomas, bone cysts, Graves' ophthalmopathy and gynaecomastia. Dose measurements were carried out using thermoluminescent dosimeters. For the radiotherapy of heterotopic ossification, the effect of using lead blocks to spare lymphatic drainage on the gonadal dose was determined.

RESULTS

The ovarian and testicular total doses were found to be 2.00-680 and 2.0-39.0 mGy, respectively, depending on the gonadal location in respect to the treatment volume. The introduction of blocks into the primary beam resulted in an increase in gonadal dose up to a factor of 1.7. The radiation-induced risk of hereditary disorders in future generations was (1.0-40.8) x 10(-4) and (1.0-23.4) x 10(-4) for women and men, respectively.

CONCLUSIONS

Radiation therapy of benign diseases always resulted in gonadal doses below 1 Gy and therefore there was no risk for permanent gonadal failure. The excess risk of radiation-induced hereditary disorders in offspring was low in comparison with the natural frequency of these effects. However, there was a considerable excess in risk after irradiation in the hip bone.

Restoration of growth plate function following radiotherapy is driven by increased proliferative and synthetic activity of expansions of chondrocytic clones

Radiation therapy encompassing an active epiphysis can negatively impact the potential for bone growth by disrupting cell-cycle progression and accelerating apoptosis and terminal differentiation in physeal chondrocytes. Despite functional derangement following radiation exposure, the irradiated growth plate retains a capacity for regeneration and recovery of growth. The purpose of this study was to characterize the initial sequence of events leading to functional growth recovery in irradiated weanling rat growth plates. We hypothesized that growth in an irradiated epiphysis would be partially restored due to the expansion of chondrocytic clones. Stereological histomorphometry was used to compare chondrocytic cell and matrix turnover between the first and second week following irradiation, and to determine the relative contribution of each of the cellular and extracellular matrix (ECM) compartments to growth. We found that restoration of growth in the irradiated limb was strongly associated with the proliferative activity and production of ECM by these chondrocytic clones, as they expand in average volume, but not in numerical density. We conclude that chondrocytes forming expansive clones and exhibiting increased mitotic and matrix synthesis activity initiate the early restoration of function in the irradiated growth plate, and would be a logical target for strategies to restore full growth potential.

Does electron and proton therapy reduce the risk of radiation induced cancer after spinal irradiation for childhood medulloblastoma? A comparative treatment planning study

The aim of this treatment planning comparison study was to explore different spinal irradiation techniques with respect to the risk of late side-effects, particularly radiation-induced cancer. The radiotherapy techniques compared were conventional photon therapy, intensity modulated x-ray therapy (IMXT), conventional electron therapy, intensity/energy modulated electron therapy (IMET) and proton therapy (IMPT).CT images for radiotherapy use from five children, median age 8 and diagnosed with medulloblastoma, were selected for this study. Target volumes and organs at risk were defined in 3-D. Treatment plans using conventional photon therapy, IMXT, conventional electron therapy, IMET and IMPT were set up. The probability of normal tissue complication (NTCP) and the risk of cancer induction were calculated using models with parameters-sets taken from published data for the general population; dose data were taken from dose volume histograms (DVH). Similar dose distributions in the targets were achieved with all techniques but the absorbed doses in the organs-at-risk varied significantly between the different techniques. The NTCP models based on available data predicted very low probabilities for side-effects in all cases. However, the effective mean doses outside the target volumes, and thus the predicted risk of cancer induction, varied significantly between the techniques. The highest lifetime risk of secondary cancers was estimated for IMXT (30%). The lowest risk was found with IMPT (4%). The risks associated with conventional photon therapy, electron therapy and IMET were 20%, 21% and 15%, respectively. This model study shows that spinal irradiation of young children with photon and electron techniques results in a substantial risk of radiation-induced secondary cancers. Multiple beam IMXT seems to be associated with a particularly high risk of secondary cancer induction. To minimise this risk, IMPT should be the treatment of choice. If proton therapy is not available, advanced electron therapy may provide a better alternative.

Murine EMT-6 carcinoma: high therapeutic efficacy of microbeam radiation therapy

Microbeam radiation therapy is an experimental modality using parallel arrays of thin (<100 micro m) slices of synchrotron-generated X rays (microplanar beams, microbeams). We used EMT-6 murine mammary carcinoma subcutaneously inoculated in the hind legs of mice to compare the therapeutic efficacies of single-fraction, unidirectional (1) "co-planar" microbeams (an array of vertically oriented microplanar beams), (2) "cross-planar" microbeams (two arrays of parallel microbeams propagated in the same direction, one with vertically and the other with horizontally oriented microplanar beams), and (3) seamless (broad) beams from the same synchrotron source. The microbeams were 90 micro m wide and were spaced 300 micro m on center; the median energy in all beams was 100 or 118 keV. Tumor ablation rates were 4/8, 4/8 and 6/7 for a 410-, 520- and 650-Gy in-slice cross-planar microbeam dose, respectively, and 1/8, 3/8, 3/7 and 6/8 for a 23-, 30-, 38- and 45-Gy broad-beam dose, respectively. When the data were pooled from the three highest doses (same average tumor ablations of 50-60%), the incidences of normal-tissue acute toxicity (moist desquamation and epilation) and delayed toxicity (failure of hair regrowth) were significantly lower for cross-planar microbeams than broad beams (P < 0.025). Furthermore, for the highest doses in these two groups, which also had the same tumor ablation rate (>75%), not only were the above toxicities lower for the cross-planar microbeams than for the broad beams (P < 0.02), but severe leg dysfunction was also lower (P < 0.003). These findings suggest that single-fraction microbeams can ablate tumors at high rates with relatively little normal-tissue toxicity.

Malignant neoplasms after radiation therapy for peptic ulcer

Most information on radiation-related cancer risk comes from the Life Span Study (LSS) of the Japanese atomic bomb survivors. Stomach cancer mortality rates are much higher in Japan than in the U.S., making the applicability of LSS findings to the U.S. population uncertain. A unique cohort of U.S. patients who were irradiated for peptic ulcer to control gastric secretion provides a different perspective on risk. Cancer mortality data were analyzed and relative risks estimated for 3719 subjects treated by radiotherapy (mean stomach dose 14.8 Gy) and/or by surgery and medication during the period 1936-1965 and followed through 1997 (average 25 years). Compared to the U.S. rates, stomach cancer mortality was significantly increased for irradiated and nonirradiated patients (observed/expected = 3.20 and 1.52, respectively). We observed strong evidence of exposure-related excess mortality from cancer of the stomach (RR 2.6, 95% CI 1.3, 5.1), pancreas (RR 2.7, 95% CI 1.5, 5.1), and lung (RR 1.5, 95% CI 1.1, 2.1), with commensurate radiation dose responses in analyses that included nonexposed patients. However, the dose responses for these cancers were not significant when restricted to exposed patients. Our excess relative risk per gray estimate of 0.20 at doses <or=10 Gy (95% CI 0, 0.73) is consistent with the estimate of 0.24 (95% CI 0.10, 0.40) obtained from the LSS study with the linear model.

Response of avian embryonic brain to spatially segmented x-ray microbeams

Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain. Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three. Other types of treatment for pediatric brain tumors are frequently ineffective. Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors. In our studies, duck embryos were irradiated at 3-4 days prior to hatching. Irradiation was carried out using a single exposure of synchrotron-generated X-rays, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam. The individual microplanar beams had a width of 27 microm and height of 11 mm, and a center-to-center spacing of 100 microm. Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam. The biological end point employed in the study was ataxia. This neurological symptom of radiation damage to the brain developed within 75 days of hatching. Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group. However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group. These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality. When the microbeam dose was normalized to the full volume of the irradiated tissue. i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam irradiation as compared with broad beam irradiation.

Role of onlay grafting with minimal internal fixation for occipitocervical fusion in oncologic patients

The choice of fixation for occipitocervical arthrodesis remains controversial, especially in oncologic patients who need further radiographic evaluation or postoperative radiotherapy. We studied the long-term outcome of 20 patients who underwent occipitocervical fusions using onlay corticocancellous bone graft and wiring, with postoperative halo vest immobilization. Eight of these patients had postoperative radiotherapy for spinal tumors (group I), and 12 patients had occipitocervical fusions for other pathologies that did not require postoperative radiotherapy (group II). All patients had solid arthrodeses; however, there was a difference in the average time to fusion between patients who received pre- or postoperative radiotherapy and those who did not (p = 0.11). At an average follow-up of 54.5 months (range 24-92 months) 15 of 20 patients (75%) had excellent or good outcomes. A high fusion rate can be expected with reasonable intraoperative or postoperative complications.

Cardiac toxicity following high-dose cyclophosphamide, cisplatin, and BCNU (STAMP-I) for breast cancer

We retrospectively evaluated 443 breast cancer patients treated with high-dose cyclophosphamide, cisplatin, and BCNU (STAMP-I) with autologous stem cell support to characterize the cardiac toxicity of this regimen. Patients had stage II-III (n = 243) or stage IV (n = 200) breast cancer. We observed an overall 5.1% incidence of cardiac complications, both clinical and subclinical, in the whole group: 4.9% in stage II-III and 5.5% in stage IV patients. Clinical cardiomyopathy (CMP) was observed in 1.6% of stage II-III patients (1 case of fatal grade 5 toxicity and 3 cases of grade 3 CMP) and in 3.5% of patients with stage IV disease (1 case of grade 4 and 6 cases of grade 3). The incidence of cardiac toxicity did not differ significantly between the groups. Prior radiation therapy to the mediastinum or left chest wall (P = .001) and advanced age (P = .01) were independent predictors of an increased risk of the appearance of this complication. No pharmacodynamic correlation was observed between any of the 3 drugs and cardiac toxicity.

Subacute neuropathological effects of microplanar beams of x-rays from a synchrotron wiggler

Microplanar beam radiation therapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and macroscopic breadth (i.e., microplanar). Thirty-six rats were exposed head-on either to an upright 4-mm-high, 20- or 37-microns-wide beam or to a horizontal 7-mm-wide, 42-microns-high beam of mostly 32- to 126-keV, minimally divergent x-rays from the X17 wiggler at the National Synchrotron Light Source at Brookhaven National Laboratory. Parallel slices of the head, separated at either 75 or 200 microns on center, were exposed sequentially at 310-650 grays (Gy) per second until each skin-entrance absorbed dose reached 312, 625, 1250, 2500, 5000, or 10,000 Gy. The rats were euthanized 2 weeks or 1 month later. Two rats with 10,000-Gy-entrance slices developed brain tissue necrosis. All the other 10,000- and 5000-Gy-entrance slices and some of the 2500- and 1250-Gy-entrance slices showed loss of neuronal and astrocytic nuclei and their perikarya. No other kind of brain damage was evident histologically in any rat with entrance absorbed doses < or = 5000 Gy. Brain tissues in and between all the 312- and 625-Gy-entrance slices appeared normal. This unusual resistance to necrosis is central to the rationale of microplanar beam radiation therapy for brain tumors.

Leukemia mortality after X-ray treatment for ankylosing spondylitis

Leukemia mortality has been studied in 14,767 adult ankylosing spondylitis patients diagnosed between 1935 and 1957 in the United Kingdom, of whom 13,914 patients received X-ray treatment. By 1 January 1992, there were 60 leukemia deaths among the irradiated patients, almost treble that expected from national rates. Leukemia mortality was not increased among unirradiated patients. Among those irradiated, the ratio of observed to expected deaths for leukemia other than chronic lymphocytic leukemia was greatest in the period 1-5 years after the first treatment (ratio = 11.01, 95% confidence interval 5.26-20.98) and decreased to 1.87 (95% confidence interval 0.94-3.36) in the 25+ year period. There was no significant variation in this ratio with sex or age at first treatment. The ratio for chronic lymphocytic leukemia was slightly but not significantly raised (ratio = 1.44, 95% confidence interval 0.62-2.79). Most irradiated patients received all their exposure within a year. Based on a 1 in 15 random sample, the mean total marrow dose was 4.38 Gy. Doses were nonuniform, with heaviest doses to the lower spine. The risk for nonchronic lymphocytic leukemia was adequately described by a linear-exponential model that allowed for cell sterilization in heavily exposed parts of the marrow and time since exposure. Ten years after first exposure, the linear component of excess relative risk was 12.37 per Gy (95% confidence interval 2.25-52.07), and it was estimated that cell sterilization reduced the excess relative risk by 47% at 1 Gy (95% confidence interval 17%-79%). The average predicted relative risk in the period 1-25 years after exposure to a uniform dose of 1 Gy was 7.00.

Development of lymph node and pulmonary metastases after local irradiation and hyperthermia of footpad melanomas

C57BL/6 mice with syngeneic B16-F10 melanomas were treated 7 days after tumor inoculation into the footpad with local hyperthermia (HT) of 43.5 degrees C for 90 min. A combination of local 30 Gy X-irradiation (XRT) given 2, 4 or 12 h after HT cured the primary tumor in 34/35 mice, with irreversible damage to normal foot tissues in most of the animals. When 7.5, 10 or 15 Gy XRT were delivered 4, 18 or 24 h after HT, there were only a small number of cures and also a much smaller incidence of irreversible normal tissue damage. HT alone resulted in a significant (P less than 0.001) increase in metastases to regional lymph nodes (RLN) and the lungs. The 'curative' doses of combined XRT and HT resulted in a significant (P less than 0.001) decrease in metastasis to RLN and to the lungs. Conversely, subcurative doses of combined therapy resulted in an increase in RLN and lung metastasis (P less than 0.001). Abdominal lymph node metastasis, not usually seen in control mice, is markedly increased after HT alone or in combination with subcurative XRT (P less than 0.001). The overall survival of mice treated with HT alone is decreased (P less than 0.0028). The survival of mice treated with HT followed 4, 18 or 24 h later with 10 Gy XRT is further decreased (P less than 0.0025). These data show that subcurative HT, or XRT plus HT, increases the incidence of spontaneous metastasis in this syngeneic mouse melanoma model. Curative doses prevent this effect on metastasis, but there is an unacceptable incidence of irreversible damage to the tumor-bearing foot. The cause(s) of this phenomenon are not known.

Mortality in a cohort of radiation treated childhood skin hemangiomas

Mortality was studied in 18,357 patients (33% males and 67% females) with skin hemangioma admitted to Radiumhemmet between 1920 and 1959. The treatments of the hemangiomas were performed by radium-226 sources (13,094 patients) or x-ray therapy (2,540 patients). In 2,723 patients no radiotherapy was given. The median age was 6 months for the treated patients and 8 months for the patients not receiving radiotherapy. Between 1920 and 1951 a total of 154 patients were reported dead. The cohort was matched with the Swedish Cause of Death Register between 1952 and 1985. During that period 504 died, in 146 patients the cause of death was cancer or leukemia. The total number of person-years at risk was 587,426. In patients treated with radium-226 or orthovoltage x-rays, 410 deaths occurred (standardized mortality ratio (SMR) = 1.07; ns). In patients given contact therapy 34 deaths occurred (SMR = 0.82; ns) and in the not irradiated group 60 deaths occurred (SMR = 0.78; ns). Patients treated with radium-226 or orthovoltage x-rays had an SMR of 1.34 for all cancers combined (p less than 0.05). For patients treated between 1920 and 1939 the SMR for cancer was 1.53 (p less than 0.05) as compared to an SMR of 1.16 (ns) for those treated between 1940 and 1959.

Grenz ray therapy: practical aspects of protecting office personnel from radiation

The exposure to grenz rays of office personnel handling a grenz ray unit working with 10 kV voltage was investigated for different treatment situations. Scattered and leakage radiation, and primary radiation at some distance from the grenz ray unit were measured. Air absorption was found to be most important. Direct exposure of the operator to the primary grenz ray beam at a distance of 4 m was practically nil. At a distance of 2 m from the unit, the operator is permitted to be exposed 100 h per year; at a distance of 1 m, the permitted exposure of the direct beam is 3 h per year. Scattered and leakage radiation from the unit was of no importance and certain clothing was demonstrated to promote absorption.

A double-blind study of Grenz ray therapy in chronic eczema of the hands

The effect of Grenz ray therapy as an adjunct to topical therapy in chronic symmetrical eczema of the hands was assessed in 24 patients by randomly allocating active treatment to one hand while the other, which received simulated therapy, served as a control. Three Gy of Grenz rays were applied on six occasions at intervals of 1 week. There was a significantly better response to active treatment 5 and 10 weeks after the start of treatment compared with the untreated control.

Comparison of Grenz rays versus placebo in the treatment of chronic hand eczema

A double-blind trial was performed on 30 patients with bilateral symmetrical constitutional hand eczema, resistant to previous treatment. There was no difference in efficacy between Grenz rays in a total dose of 900 rad (9 Gy) given in three equal doses at 21-day intervals, and placebo therapy given in a similar treatment schedule.

Skin cancer caused by grenz rays

A 30-year-old woman developed chronic radiodermatitis and five squamous cell carcinomas within 7 years following a 16-year period of repeated grenz irradiations given to her psoriasis. The estimated cumulative dose of grenz radiation was approximately 3,000 rads (r) to each treated area. This case, illustrating a rather underestimated carcinogenic potential of grenz rays, is interpreted in light of the available literature on the subject. The technical bases of grenz ray therapy are also briefly reviewed.

Electron microscopic observations of Langerhans' cells in human epidermis irradiated with grenz rays

The effect of grenz rays on Langerhans' cells and epidermal morphology was studied at electron microscopic resolution in humans. Biopsies were obtained before and after grenz ray therapy (3 Gy X 3, 1 week interval) from 6 subjects. There was a pronounced reduction of the number of Langerhans' cells 24 hours after the final treatment. There appeared to be no consistent differences in keratinocyte morphology or changes of the intercellular space.

[An extremely long Abbé flap for simultaneous reconstruction of a defect of the upper lip and the columella]

X-ray treatment of a small haemangioma of the upper lip in a child led to severe health consequences, about 20 years later. Besides an extremely hypoplastic upper lip with whistle tip deformity, an exulcerated basal-cell carcinoma had developed upon the columella and the lower part of the nasal tip. The goal of the operation was to perform a radical excision of the tumor but also to obtain an aesthetically pleasing reconstruction of the upper lip and a simultaneous covering of the defect, resulting from the tumor excision on the columella and the nasal tip. To achieve this, we have chosen an Abbé-flap, with an extremely long cutaneous pedicle. While in Abbé-flaps the relation between muscular and cutaneous part usually is about 1:2, in this case it was about 1:5. With this flap it was possible to cover in one stage the defect in the upper lip, the columella and the nasal tip.

Polyvinylpyrrolidone (povidone) storage in RX-damaged skin following procaine-povidone intramuscular injections

A man, aged 67, has been treated in 1968 by X-rays for a basal-cell carcinoma of the back. The treatment was followed by an ulcerative radiodermatitis. 3 years later, the patient was treated by ten intramuscular injections of procaine-polyvinylpyrrolidone (or procaine-povidone) for sciatic neuralgia. An orange infiltration appeared progressively around the radiodermatitis. The area was excised in 1979 and polyvinylpyrrolidone (povidone) storage, responsible for the ring-shaped orange hue, could be demonstrated in the dermis and subcutaneous fat. Special stainings confirmed the presumed chemical nature of the deposits. 3 cases of povidone pseudotumours following procaine-povidone injections had been described previously. The preferential deposit of povidone in RX-damaged skin is discussed.

Occurrence of tumors and effects on longevity after limited x-irradiation in man

An analysis was made of survival times and causes of death of patients given local irradiation in small dosage during 1948--1960. The study involved 61 patients with peptic ulcers in whom hyperacidity was treated by partial gastrectomy and gastric irradiation, and their mortality was compared with that of 61 age- and sex-matched gastrectomized but nonirradiated control patients. For both groups the survival rates were related to "normal population" survival rates calculated from age-, sex- and year-specific mortality rates for the population of Victoria. Ten years after irradiation the relative survival rates of the irradiated and control groups began to diverge, due to more deaths than expected in the irradiated group. The irradiated group had a significantly increased number of deaths due to cancer, particularly carcinoma of the stomach, as well as an increase in deaths not caused by cancer. The mortality of the nonirradiated control patients was not significantly greater than that of the normal population.

Adverse effects of superficial X-ray therapy and recommendations for safe use in benign dermatoses

The danger of superficial radiotherapy for benign dermatoses has been exaggerated. It is safe if certain precautions are observed. The permissible life time maximum cumulative dose of conventional superficial X rays generated at 50 kV given to any area of skin is 1000 R, and of grenz rays, 5000 R.

Surgical and external ureteric trauma

This paper details the aetiology, presentation, diagnosis, prophylaxis, treatment, and results, of 84 surgical and external ureteric injuries. Although the incidence of surgical ureteric trauma was found to be low it was related to both the particular operation performed and certain faults in surgical technique. The series emphasizes the importance of prophylaxis, early diagnosis, and specific therapy. There were 94 operations carried out on the 84 ureters, resulting in 22 nephrectomies and 63 open repair procedures, of which 55 were regarded as successful and 8 as failures.

Acquired coarctation of the aorta--a long-term complication of irradiation

Images

Hypothyroidism after x irradiation to the neck: three case reports and a brief review of the literature

Three patients who developed hypothyroidism after x irradiation to the neck are presented. The first two cases demonstrate that patients can develop clinical and chemical hypothyroidism after a very short interval following radiotherapy. Hypothyroidism developed in the first patient in the absence of surgical manipulation of the neck, or a large iodine load 4 months after receiving 6800 rad of x-ray therapy to his neck for carcinoma of the larynx. The second patient developed hypothyroidism approximately 6 months after his radiotherapy for carcinoma of the esophagus. Both of these patients demonstrated high titers of serum antithyroid antibodies. A third patient with Hodgkin's disease did not manifest clinical symptoms and signs of hypothyroidism until 6 years after radiation therapy. These cases demonstrate the variability of onset of hypothyroidism after radiotherapy and emphasize the need for careful evaluation of thyroid function before and after neck irradiation.

Comparison of 99mTc and 123I for thyroid imaging

Thyroid images were obtained with 99mTc and 123I, using a scintillation camera and pinhole collimator, from 85 patients selected from over 1,000 patients predisposed to the development of thyroid neoplasms by prior radiotherapy. In 66 of 85 patients 99mTc and 123I gave essentially similar information, whereas in 19 patients some thyroid-image disparity was seen. In 11 of these 19, focal areas of increased 99mTc concentration were not seen with 123I. Radioiodide images showed slightly better contrast than the 99mTc images but required a longer imaging time and usually did not provide more information; in a few cases 99mTc showed abnormalities more readily. Regardless of which radionuclide was used, oblique views were needed to define some abnormalities. Currently 123I does not provide significant advantages over 99mTc for routine thyroid imaging. However, 123I is preferred in patients with very poor thyroid function and in those with suspected retrosternal thyroid tissue. In addition, areas of increased 99mTc concentration should also be studied with 123I.

Late effects of x irradiation in patients treated for metropathia haemorrhagica

We have previously reported on the causes of death among 2,068 patients treated with X irradiation for metropathia haemorrhagica at three Scottish radiotherapy centres between 1940 and 1960 (Doll and Smith, 1968). This cohort of women has now been followed up for a further seven years. 500 (24 per cent) women have now died, 78 (3-8 per cent) have emigrated and 25 (1-2 per cent) could not be traced. The numbers of deaths from different causes have been compared with the numbers expected in a population of similar age and sex exposed to the Scottish national mortality rates over the same period. An excess of deaths from leukaemia (seven observed, 2-3 expected) and of cancers of the heavily irradiated sites (59 observed, 40-1 expected) continues to be observed five or more years after treatment. There is no indication of any change in the excess death rate, due to cancers of sites in the radiation field, with time since treatment up to at least 20 years after the radiation exposure. Over the same period the number of deaths from cancer of the breast was below expectation (ten observed, 22-3 expected) and no increased mortality from coronary disease was seen (102 observed, 100-9 expected). The mean dose of radiation to the bone marrow has been determined for each woman ant it is estimated that the excess rate of leukaemia in the first 20 years after treatment is about 1-1 per million women per year per rad. This figure is in accord with the estimates derived from the survivors of the atomic bomb explosions in Hiroshima and Nagasaki and among patients with ankylosing spondylitis treated with X irradiation. However, the finding of no excess risk of leukemia among women treated with irradiation for cancer of the cervix (Hutchison, 1968) suggests that the simple assumption of a linear dose-response relationship for leukaemia is incorrect, at least when high doses of radiation are delivered to a small volume of marrow.

Follow-up study of patients treated by X-ray epilation for Tinea capitis; resurvey of post-treatment illness and mortality experience

This is the second follow-up study of 2,215 persons who during childhood between 1940 and 1959 had been given x-ray therapy for tinea capitis and of 1,395 persons well matched for age, sex, and race who were treated for the same disease during the same period without the use of x-ray therapy. The major finding of the study was an excess incidence in the irradiated cases of tumors of the head and neck including the skin, brain, thyroid, and parotid. However, between the groups there was no difference in death due to malignant neoplasms or any other cause. Among white patients, a 40% excess of treated psychiatric disorders was observed in the irradiated group, but there was no difference among blacks.

The tricho system: hypertrichosis, radiation, and cancer

Five women in their 6th to 8th decades were treated for facial hypertrichosis in Erie, Pennsylvania, 30 to 40 years ago. The epilations were performed with an X-ray device called "Tricho System," which was manufactured, sold, and proclaimed safe by its physician-inventor. The beauty shop operator who administered these treatments may or may not have received "instruction" by the company in the operation of the equipment. At varying intervals, each of the 5 women developed radiodermatitis and basal cell and/or squamous cell carcinoma at the sites of epilation. All presented to the plastic surgical service at the Hamot Medical Center in Erie, Pennsylvania. Two underwent massive radical resective surgery, 2 required extensive excision and resurfacing, and 1 refused resective surgery although she had had a previous surgical attempt 17 years earlier. Case histories are presented in detail. This series is representative of the epidemic nature of Tricho-System-induced disease.