Radiotherapy for tumors of the mediastinum - state of the art.

Mediastinal tumors encompass a diverse range of malignancies, originating within or spreading to the mediastinum. The administration of radiotherapy within the anatomical confines of the mediastinum presents unique challenges owing to the close proximity of critical organs, including the heart, lungs, esophagus, and spinal cord. However, recent progress in imaging techniques, treatment modalities, and our understanding of tumor biology has significantly contributed to the development of effective and safe therapeutic strategies for mediastinal diseases. This review article aims to explore the latest innovations in radiotherapy and their practical applications in the management of mediastinal tumors, with a primary focus on lymphomas, thymomas, and thymic carcinomas. By examining these advancements, we seek to provide valuable insights into the current state of the art in radiotherapy for mediastinal malignancies, ultimately fostering improved patient outcomes and clinical decision-making.

Long-Term Results of Postoperative Hypofractionated Accelerated Breast and Lymph Node Radiotherapy (HypoAR) with Hypofractionated Boost.

We report long-term results (median follow-up 12 years) of hypofractionated accelerated radiotherapy (HypoAR) in patients treated with breast-conserving surgery. In total, 367 women were treated with HypoAR. Axillary and supraclavicular area (ASA) were treated in patients with involved nodes. In total, 290 patients (scheme A) received 3.5 Gy/day ×10 fractions (breast/ASA) followed by two 4 Gy fractions with electrons to the affected breast quadrant within 16 days. In total, 77 patients (Scheme B) received 2.7 Gy/day for 16 consecutive fractions (breast/ASA) within 22 days, while concurrently, the affected breast quadrant received an electron booster dose of 0.8 Gy for the first 13 fractions. Amifostine was offered to 252/367 patients. Early radiation toxicity was minimal. Regarding late toxicities, symptomatic breast edema was noted in 2.2%, asymptomatic breast fibrosis in 1.9%, and arm lymphedema in 3.7% of patients. Amifostine reduced early radiation dermatitis (p = 0.001). In total, 2.2% of patients developed contralateral breast and 1.6% other carcinomas. Locoregional recurrence (LR) occurred in 3.1% of patients (0% for in situ carcinomas). Positive margins after surgery, extracapsular node invasion, and HER2-enriched/triple-negative tumors were linked with significantly worse LR-free survival. The involvement of more than three nodes and luminal type other than A were independent prognostic variables of metastasis and death events. HypoAR delivering a biological dose of 50-52 Gy to the breast/ASA is a safe and effective therapy for patients treated with conservative surgery. The risk of carcinogenesis is low. Positive surgical margins, extracapsular node invasion, and HER2-enriched/triple-negative phenotypes appear as a cluster of features linked with a higher risk for locoregional relapse.

Comparative radiobiological analysis and preliminary results of Ultra hypofractionated accelerated radiotherapy for low-risk prostate cancer patients.

PURPOSE: Moderately accelerated hypofractionation (HypoAR) has been recently established as a standard radiotherapy scheme for low-risk prostate cancer. The application of ultra-hypofractionated regimens (ultra-HypoAR), with fraction size above 5 Gy, is also widely tested. METHODS: We applied Image Guided Radiation Therapy (IGRT) ultra-HypoAR delivered with Volumetric Modulated Arc Therapy (VMAT) technique in low-risk prostate cancer patients (5.75 Gy/fraction, 40.25 Gy total dose, two fractions per week). A comparative radiobiological analysis of Dose-Volume Ηistograms (DVH) obtained for target volumes and organs at risk was performed, investigating the advantages and disadvantages of ultra-HypoAR and conventional radiotherapy regimens (CRT). Early clinical results on efficacy and toxicity are also reported. RESULTS: We calculated the Normalized Total Dose (NTD) and NTD with time correction (NTD_T)-based biological Dose- Volume Histograms (bDVH) for bladder and rectum tissue late effects (α/ß=4 Gy) and early effects (α/ß=10 Gy). Ultra-HypoAR produced a significantly lower biological dose burden than CRT, for both early and late responding tissue components of the bladder and rectum, whether calculated for time-correction or not (p<0.0001). Our clinical experience showed that the ultra-HypoAR regimen produced minimal early and late radiation sequelae. The median PSA levels dropped from 9.1 to 0.75 and 0.45 ng/ml at 6 and 12 months, respectively, after the end of therapy. CONCLUSIONS: In conclusion, radiobiological analysis of DVHs and preliminary clinical experience predict a better efficacy and low early and late toxicity profile for the tested seven-fraction VMAT ultra-HypoAR regimen with IGRT.

Cutaneous squamous-cell carcinoma of the head-neck area refractory to chemo-radiotherapy: benefit from anti-PD-1 immunotherapy.

OBJECTIVE: Radiotherapy provides excellent results in locally advanced cutaneous squamous-cell carcinoma of the head and neck area (cSCC-HN), with a 2-year local progression-free interval obtained for about 80% of patients. Overexpression of immune checkpoint co-inhibitory molecules, like PD-L1 (programmed death ligand 1), by cancer cells may define local immunosuppression, tumour escape from immune surveillance and reduced radiotherapy efficacy. METHODS: A 65-year-old female, with a large exophytic cSCC-HN invading adjacent soft tissues, was treated with hypofractionated accelerated chemo-radiotherapy. The patient received four bi-weekly cycles of chemotherapy concurrently with eight fractions of 5.5 Gy (two fractions per week). Two months after the end of chemo-radiotherapy, the tumour was stable in dimensions, without any signs of symptomatic relief. The patient was, after that, treated with anti-PD-1 immunotherapy (nivolumab). The tumour gradually regressed, reaching partial response after four cycles and complete response after 16 cycles of nivolumab. No side-effects related to immunotherapy were recorded. The patient is alive and without evidence of disease 28 months after radiotherapy. CONCLUSIONS: Treatment of patients with chemo- and radio-resistant cSCC-HN with immunotherapy may optimize the efficacy of radiotherapy by stimulating immunological tumour rejection mechanisms. cSCC-HN patients who fail to respond to chemo-radiotherapy completely are expected to benefit the most from immunotherapy because of the radio-vaccination effect expected from the preceded radiotherapy.

Is Locally Advanced Head-Neck Cancer One More Candidate for Accelerated Hypofractionation?

BACKGROUND/AIM: Hypofractionated accelerated radiotherapy (HypoAR) is widely applied for the treatment of early laryngeal cancer. Its role in locally advanced head-neck cancer (LA-HNC) is unexplored. PATIENTS AND METHODS: We present results of a prospective trial on 124 patients with LA-HNC, treated with radio-chemotherapy with three different HypoAR fractionations (3.5 Gy/day × 14-15 fractions, 2.7 Gy/day × 20-21 fractions, and 2.5 Gy/day × 21-22 fractions). RESULTS: Protraction of the overall treatment time due to oropharyngeal mucositis was enforced in 18/57 laryngeal, 6/19 nasopharyngeal, and 15/48 cancer patients with other tumors. Regarding late toxicities, laryngeal edema grade 3 was noted in 5/57 patients with laryngeal cancer, while severe dysphagia was noted in 4/124 and tracheoesophageal fistula formation in 1/124 patients. The complete response rates obtained were 73%, 84%, and 67% in patients with laryngeal, nasopharyngeal, and other tumors, respectively. The 3-year locoregional progression-free survival was 58%, 73%, and 55%, respectively. CONCLUSION: HypoAR chemoradiotherapy is feasible, with acceptable early and late radiotherapy toxicities, response rates and LPFS.

Technical Note: Partial body irradiation of mice using a customized PMMA apparatus and a clinical 3D planning/LINAC radiotherapy system.

PURPOSE: In vivo radiobiology experiments involving partial body irradiation (PBI) of mice are of major importance because they allow for the evaluation of individual organ tolerance; overcoming current limitations of experiments using lower dose, whole body irradiation. In the current study, the authors characterize and validate an effective and efficient apparatus for multiple animal PBI, directed to the head, thorax, or abdomen of mice. METHODS: The apparatus is made of polymethylmethacrylate and consists of a rectangular parallelepiped prism (40 cm × 16 cm × 8 cm), in which five holes were drilled to accomodate standard 60 ml syringes, each housing an unanesthetized, fully immobilized mouse. Following CT-scanning and radiotherapy treatment planning, radiation fields were designed to irradiate the head, thorax, or abdomen of the animal. Thermoluminescent dosimeters (TLDs) were used to confirm the treatment planning dosimetry for primary beam and scattered radiation. RESULTS: Mice are efficiently placed into 60 ml syringes and immobilized, without the use of anesthetics. Although partial rotational movement around the longitudinal axis and a minor 2 mm forward/backward movement are permitted, this does not compromise the irradiation of the chosen body area. TLDs confirmed the dose values predicted by the treatment planning dosimetry, both for primary beam and scattered radiation. CONCLUSIONS: The customized PMMA apparatus described and validated is cost-effective, convenient to use, and efficient in performing PBI without the use of anesthesia. The developed apparatus permits the isolated irradiation of the mouse head, thorax, and abdomen. Importantly, the apparatus allows the delivery of PBI to five mice, simultaneously, representing an efficient way to effectively expose a large number of animals to PBI through multiple daily fractions, simulating clinical radiotherapy treatment schedules.

Evaluation of the alamarblue assay for adherent cell irradiation experiments.

The AlamarBlue assay is based on fluorometric detection of metabolic mitochondrial activity of cells. In this study, we determined the methodology for application of the assay to radiation response experiments in 96-well plates. AlamarBlue was added and its reduction measured 7 hours later. Selection of the initial number of plated cells was important so that the number of proliferating cells remains lower than the critical number that produced full AlamarBlue reduction (plateau phase) at the time points of measurements. Culture medium was replaced twice a week to avoid suppression of viability due to nutrient competition and metabolic waste accumulation. There was no need to replace culture medium before adding AlamarBlue. Cell proliferation continued after irradiation and the suppression effect on cell viability was most evident on day 8. At this time point, by comparing measurements from irradiated vs. non-irradiated cells, for various dose levels, a viability dose response curve was plotted. Immediately after the 8(th) day (nadir), cells started to re-grow at a rate inversely related to the radiation dose. By comparing measurements at the time point of nadir vs. a convenient subsequent time point, re-growth dose response abilities were plotted, simulating clonogenic assays.

Establishment and validation of a method for multi-dose irradiation of cells in 96-well microplates.

Microplates are useful tools in chemistry, biotechnology and molecular biology. In radiobiology research, these can be also applied to assess the effect of a certain radiation dose delivered to the whole microplate, to test radio-sensitivity, radio-sensitization or radio-protection. Whether different radiation doses can be accurately applied to a single 96-well plate to further facilitate and accelerated research by one hand and spare funds on the other, is a question dealt in the current paper. Following repeated ion-chamber, TLD and radiotherapy planning dosimetry we established a method for multi-dose irradiation of cell cultures within a 96-well plate, which allows an accurate delivery of desired doses in sequential columns of the microplate. Up to eight different dose levels can be tested in one microplate. This method results in fast and reliable estimation of radiation dose-response curves.

Postmastectomy hypofractionated and accelerated radiation therapy with (and without) subcutaneous amifostine cytoprotection.

PURPOSE: Postmastectomy radiation therapy (PMRT) provides major local control and survival benefits. More aggressive radiation therapy schemes may, however, be necessary in specific subgroups, provided they are safely administered. We report the tolerance and efficacy of a highly accelerated and hypofractionated regimen (HypoARC). METHODS AND MATERIALS: One hundred twelve high-risk patients who had undergone mastectomy received 10 consecutive fractions of 3.5 Gy in 12 days (thoracic wall and axillary/supraclavicular areas). Two consecutive additional fractions of 4 Gy were given to the surgical scar area (electrons 8-10 MeV) and 1 3.5-Gy fraction to the axilla (in cases with extensive nodal involvement). A minimum follow-up of 24 months (median, 44 months) was allowed before analysis. Of 112 patients, 21 (18.7%) refused to receive amifostine, the remaining receiving tolerance-based individualized doses (500-1000 mg/day subcutaneously). RESULTS: By use of a dose individualization algorithm, 68.1%, 11%, and 18.7% of patients received 1000 mg, 750 mg, and 500 mg/day of amifostine. Patchy moist skin desquamation outside and inside the booster fields was noted in 14 of 112 (12.5%) and 26 of 112 (23.2%) patients, respectively. No case of acute pneumonitis was recorded. High amifostine dose offered a significant skin protection. Within a median follow-up time of 44 months, moderate subcutaneous edema outside and within the booster thoracic area was noted in 5 of 112 (4.4%) and 8 of 112 (7.1%) cases, respectively. Intense asymptomatic radiographic findings of in field lung fibrosis were noted in 4 of 112 (3.6%) patients. Amifostine showed a significant protection against lung and soft tissue fibrosis. A 97% projected 5-year local relapse free survival and 84% 5-year disease-specific survival were recorded. Lack of steroid receptor expression, simple human epidermal growth factor 2 positivity, or triple negative phenotype defined higher metastasis rates but had no effect on local control. CONCLUSIONS: PMRT with HypoARC showed an excellent early and short-term late toxicity profile, and amifostine further reduced early and late radiation sequelae. Encouraging local control rates are obtained in high-risk subgroups.

Postoperative pelvic hypofractionated accelerated radiotherapy with cytoprotection (HypoARC) for high-risk or recurrent prostate cancer.

AIM: We evaluated the feasibility and efficacy of postoperative hypofractionated and accelerated radiotherapy supported with amifostine cytoprotection (HypoARC) in patients with high-risk or recurrent prostate cancer. PATIENTS AND METHODS: Fourty-eight patients were recruited (median follow-up=41 months; range=12-84 months). Twenty-one received HypoARC after surgery and 27 at biochemical relapse. Radiotherapy was given with a 3D-conformal technique, delivering 2.7 Gy/day to the pelvis and 3.4 Gy to the peri-prostatic region for 14 fractions. A 15th fraction increased the total dose to the peri-prostatic area to 51 Gy (15×3.4 Gy) in 19 days. Amifostine was delivered before each radiotherapy fraction at an individualized (by tolerance) dose (0-1000 mg). RESULTS: Amifostine was delivered subcutaneously at 1000 mg in 35/48 (72.9%) patients, while lower doses were tolerated by the remaining patients. Twenty-six (54.2%) patients accomplished therapy without delays, while acute toxicities enforced 1 to 2 week delays in 11/48 patients (22.9%). Grade 2 proctitis was noted in 18.7%, while substantial bleeding occurred in 8.3% of patients. Grade 1 dysurea was noted in 27.1%, while diarrhea grade 2 appeared in 10.4% of patients. High amifostine dose was linked to a significant reduction of proctitis (p=0.04). No severe late toxicities were noted. Within a median of 41 months, 7/48 (14.6%) patients exhibited post-radiotherpy biochemical failure (in four due to metastasis). High-dose (1000 mg) amifostine defined a significantly better outcome (p=0.004), an effect sustained on multivariate analysis. CONCLUSION: Postoperative HypoARC is feasible with low-grade early and late toxicities, and emerges as a candidate for evaluation in randomized trials. The three-fold reduction of the overall treatment time renders HypoARC appealing for busy radiotherapy departments.

CT dosimetry considerations in non typical conditions: the effect of scan field of view and table height selection.

PURPOSE: To experimentally investigate the effect of the scan field of view (SFOV) selection and table height settings on the Computed Tomography Dose Index (CTDI) and the implications concerning patient effective and skin dose. METHODS: Air-kerma length product (AKLP) measurements were carried out in a helical CT scanner using a pencil type dosimeter positioned in air and inside the holes of a head and a body phantom, using all available SFOV selections and different table height settings. Furthermore, using radiotherapy verification films placed on the CT table surface, the entrance surface air kerma (ESAK) profiles were derived with different SFOV and table height selections, both with and without a phantom on top of the films. RESULTS: The AKLP is strongly dependent on the SFOV selection and the table height settings. Different SFOV selections correspond to the selection of different bowtie filters that shape the X-ray beam intensity, resulting in different ESAK values at the isocenter and at the other points within the scanning plane. With the off-center positioning the calculated CTDI values within the center and the periphery of the phantom change also, as a result of the different intensity and width of the X-ray beam to which are exposed to. CONCLUSIONS: The existing protocols for calculating effective dose are limited to only two patient anatomy-SFOV combinations and cannot account for off-center positioning. Therefore, more work will be required to estimate the effective and skin dose for non-standard SFOV-patient anatomy combinations and off-center patient positioning.

Treatment of invasive bladder cancer with conformal hypofractionated accelerated radiotherapy and amifostine (HypoARC).

INTRODUCTION: Radiotherapy (RT) for bladder cancer is as an effective alternative of cystectomy. Although rapid cancer clonogen repopulation contributes to radio-resistance, accelerated RT schemes based on ≤ 2 Gy fractions have failed to improve results. We suggest that accelerated hypofractionation (HypoARC) may be more effective, as it targets both tumors with increased clonogenic activity and tumors with low radio-sensitivity. PATIENTS AND METHODS: Eighty-two bladder cancer patients were treated with concomitant-boost conformal RT (14 × 2.7 Gy to the pelvis and 15 × 3.4 Gy to the bladder, within 19 days). Patients received a daily dose of 0/500/750/1,000 mg of amifostine using a dose-individualization algorithm (15.8%, 8.5%, 19.5%, and 56.1% of patients respectively). RESULTS: Early frequency grade 2-3, dysuria grade 1-2, diarrhea grade 2, and proctitis grade 2 appeared in 10.9%, 15.8%, 8.5%, and 13.4% of patients, respectively. The incidence of late sequelae was low (1.2% grade 2 frequency, 2.4% grade 2-3 dysuria, 2.4% grade 2-3 hematuria, 2.4% grade 2-3 incontinence). Patients receiving 1,000 mg of amifostine experienced significantly lower toxicities. The complete response rate, 3-year local control and disease specific survival rates were 86.6%, 56%, and 63%, respectively. CONCLUSIONS: HypoARC is linked with low early and late radiation toxicity, which is further reduced with the administration of high dose daily amifostine. The control and survival rates compare favorably with previously published data.

Concurrent liposomal cisplatin (Lipoplatin), 5-fluorouracil and radiotherapy for the treatment of locally advanced gastric cancer: a phase I/II study.

PURPOSE: Liposomal drugs have a better tolerance profile and are highly accumulated in the tumor environment, properties that promise an optimal radiosensitization. We investigated the feasibility of the combination of 5-fluorouracil/lecovorin-based radio-chemotherapy with the administration of high weekly dose of a liposomal platinum formulation (Lipoplatin). METHODS AND MATERIALS: Lipoplatin was given at a dose of 120 mg/m(2)/week, 5-fluorouracil at 400mg/m(2)/week (Day 1), whereas radiotherapy was given through 3.5-Gy fractions on Days 2, 3, and 4. Two groups of 6 patients received four and five consecutive cycles, respectively. RESULTS: Minimal nephrotoxicity (18.2% Grade 1) and neutropenia (9% Grade 3) was noted. Fatigue Grade 2 appeared in 25% of cases. Abdominal discomfort was reported by 18% of patients. No liver, kidney, gastric, or intestinal severe acute or late sequellae were documented, although the median follow-up of 9 months is certainly too low to allow safe conclusions. A net improvement in the performance status (from a median of 1 to 0) was recorded 2 months after the end of therapy. The response rates assessed with computed tomography, endoscopy, and biopsies confirmed 33% (2 of 6) tumor disappearance in patients treated with four cycles, which reached 80% (4 of 5) in patients receiving five cycles. CONCLUSIONS: Lipoplatin radio-chemotherapy is feasible, with minor hematological and nonhematological toxicity. The high complete response rates obtained support the testing of Lipoplatin in the adjuvant postoperative or preoperative radio-chemotherapy setting for the treatment of gastric cancer.

Tracheal cancer treated with a short course of external and endoluminal radio-chemotherapy combined with cetuximab - a case report.

Primary tumors of the trachea are rare. Such cases are presented with acute respiratory distress demanding immediate therapeutic intervention. Herein, we present a case of an unresectable second primary tracheal cancer treated with intraluminal brachytherapy (8 Gy at 1 cm from catheter) followed by a short course of external beam hypofractionated radiotherapy (4.5 Gy × 4 fractions) and a final brachytherapy fraction (8 Gy), delivering a biological dose higher than 57.5 Gy (for α/ß = 4 Gy) to the tumor within 4 weeks. Concurrent chemotherapy consisted of: fluoruracil (1000 mg/m2), leucovorin (100 mg/m2), oxaliplatin (80 mg/m2) and cetuximab (500 mg/m2), administered every two weeks for two consecutive cycles. Complete response was evident during the second brachytherapy fraction and the patient is alive with no evidence of disease, two years after therapy, without any late radiation sequel.

Postoperative accelerated radiotherapy with cytoprotection followed by three-dimensional conformal boost in patients with early endometrial/cervical cancer.

AIMS AND BACKGROUND: Adjuvant external beam radiotherapy is highly recommended for uterine carcinomas invading beyond the inner half of the myometrium or cervical stage IIa carcinomas. The addition of a booster intracavitary dose is widely used. METHODS: We assessed the feasibility and toxicity of a hypofractionated accelerated conformal radiotherapy scheme (2.7 Gy per fraction, for 14 consecutive fractions to the pelvis) supported with the cytoprotective agent amifostine (HypoARC). The amifostine dose was individualized (500-1000 mg daily subcutaneously). A booster dose of radiation was given to the vagina and stump using a 6-field 3D-conformal technique (3 x 4 Gy or 4 x 3 Gy) instead of intracavitary radiotherapy. RESULTS: Grade 2 diarrhea appeared in 9/25 (36%) and grade 1 cystitis in 7/25 (28%) cases. Analysis according to the amifostine dose level clearly showed reduced toxicity in patients receiving a daily dose of 750-1000 mg (P < 0.009). Within a median follow-up of 31 months (range, 11-52), there was only one case with grade 2 colitis (the patient had received no amifostine). None of the patients treated has relapsed locally or to distant organs within a median of 31 months of follow-up. CONCLUSIONS: It is concluded that HypoARC followed by 3D-conformal booster dose to the vagina is feasible and convenient for patients and for busy radiotherapy departments, as it reduces the overall time by 50%. When supported by high-dose daily amifostine, it has an impressively low rate of early and late radiation toxicity.

Computed tomography assessment of lung density in patients with lung cancer treated with accelerated hypofractionated radio-chemotherapy supported with amifostine.

OBJECTIVES: Lung fibrosis is a severe complication after radiotherapy in patients with nonsmall cell lung cancer and is the main undesirable late complication limiting the therapeutic ratio of thoracic radiation treatment. Here we evaluated the lung fibrosis using computed tomography scan mediated assessment of lung tissue density in long-term survivals treated with hypofractionated and accelerated radiotherapy supported with amifostine (HypoARC). METHODS: Out of 45 patients with locally advanced nonsmall cell lung cancer treated with conformal HypoARC (3.5 Gy x 15 fractions in 4 weeks) and concurrent chemotherapy, 14 are alive 16 to 47 months (median 20) after radiotherapy. Patients received 500 to 1000 mg of amifostine before each radiotherapy fraction, according to a previously described dose individualization algorithm. RESULTS: Early pneumonitis was absent in all patients, whereas lung density assessed with computed tomography scan in Hounsfield units (HU), within a median of 20 months after radiotherapy, showed marked increase in 2/6 and 0/8 patients who received 500 to 750 mg and 1000 mg of amifostine, respectively. The HU in these 2 patients increased to values below -550 HU, from initial values of -700 to -800 HU. Only one of these 2 patients had mild exertional dyspnoea. CONCLUSIONS: Given the good tolerance of daily high-dose amifostine administration and the encouraging very low rates of pneumonitis and lung fibrosis noted, despite the aggressiveness of the radio-chemotherapy regimen applied, it is suggested that the value of amifostine in chest radiotherapy should be re-evaluated in properly designed randomized clinical trials.

Hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection as short adjuvant regimen after breast-conserving surgery: interim report.

PURPOSE: Short radiotherapy schedules might be more convenient for patients and overloaded radiotherapy departments, provided late toxicity is not increased. We evaluated the efficacy and toxicity of a hypofractionated and highly accelerated radiotherapy regimen supported with cytoprotection provided by amifostine in breast cancer patients treated with breast-conserving surgery. METHODS AND MATERIALS: A total of 92 patients received 12 consecutive fractions of radiotherapy (3.5 Gy/fraction for 10 fractions) to the breast and/or axillary/supraclavicular area and 4 Gy/fraction for 2 fractions to the tumor bed). Amifostine at a dose of 1,000 mg/d was administered subcutaneously. The follow-up of patients was 30-60 months (median, 39). RESULTS: Using a dose individualization algorithm, 77.1% of patients received 1,000 mg and 16.3% received 750 mg of amifostine daily. Of the 92 patients, 13% interrupted amifostine because of fever/rash symptoms. Acute Grade 2 breast toxicity developed in 6.5% of patients receiving 1,000 mg of amifostine compared with 46.6% of the rest of the patients (p < .0001). The incidence of Grade 2 late sequelae was less frequent in the high amifostine dose group (3.2% vs. 6.6%; p = NS). Grade 1 lung fibrosis was infrequent (3.3%). The in-field relapse rate was 3.3%, and an additional 2.2% of patients developed a relapse in the nonirradiated supraclavicular area. c-erbB-2 overexpression was linked to local control failure (p = .01). Distant metastasis appeared in 13% of patients, and this was marginally related to more advanced T/N stage (p = .06). CONCLUSION: Within a minimal follow-up of 2.5 years after therapy, hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection has proved a well-tolerated and effective regimen. Longer follow-up is required to assess the long-term late sequelae.

A plesiotherapy technique for the post-operative treatment of skin cancer using Ir192 microSelectron.

We describe a technique of postoperative irradiation of skin cancer using plesiotherapy with Ir192 high dose rate microSelectron afterloading system (Nucletron, Veenendaal, Netherlands). The clinically defined area is drawn on the skin and the flexible 'skin applicator' is then orientated so that the drawn skin area is encompassed within the catheter defined surface. Using a thin pewter wire, the skin drawn area is copied on the air-adjacent surface of the applicator. Ex vivo CT simulation follows. The data are then transferred to the radiotherapy planning computer and the catheters are virtually reconstructed. The isodose curve chosen to prescribe the dose is 3 mm to 5 mm away from the skin surface. Three fractions of 8Gy are scheduled, 1 week apart, delivering a radiobiological equivalent of 48Gy of standard radiotherapy within 2 weeks. Our preliminary experience shows excellent early skin tolerance. The study is ongoing to assess efficacy and late effects.

Hypofractionated accelerated radiochemotherapy with cytoprotection (Chemo-HypoARC) for inoperable non-small cell lung carcinoma.

BACKGROUND: Concurrent radiochemotherapy and altered radiotherapy fractionation are under thorough investigation in locally advanced non-small cell lung carcinoma (NSCLC). PATIENTS AND METHODS: The efficacy and tolerance of hypofractionated accelerated radiochemotherapy supported with high dose (up to 1000 mg daily) amifostine cytoprotection (hypoARC) was examined in 31 patients. Fifteen fractions of 3.5 Gy were delivered within 28-35 days. Liposomal doxorubicin and oxaliplatin were concurrently given. RESULTS: A total of 65% of patients tolerated a daily amifostine dose of 750-1000 mg. Chemotherapy had an excellent tolerance. Grade 3 oesophagitis was noted in 7/31 (22.5%) patients. Radiation pneumonitis was absent and radiation fibrosis minimal. Complete and partial response were observed in 12/31 (38.6%) and 17/31 (54.8%) patients, respectively. The 2-year estimated local progression-free and overall survival interval were 58% and 45%, respectively. CONCLUSION: Given the simplicity of HypoARC, the very low morbidity, and the high complete response and survival rates obtained, HypoARC regimens deserve further testing.

Biological dose volume histograms during conformal hypofractionated accelerated radiotherapy for prostate cancer.

Radiobiological data suggest that prostate cancer has a low alpha/beta ratio. Large radiotherapy fractions may, therefore, prove more efficacious than standard radiotherapy, while radiotherapy acceleration should further improve control rates. This study describes the radiobiology of a conformal hypofractionated accelerated radiotherapy scheme for the treatment of high risk prostate cancer. Anteroposterior fields to the pelvis deliver a daily dose of 2.7 Gy, while lateral fields confined to the prostate and seminal vesicles deliver an additional daily dose of 0.7 Gy. Radiotherapy is accomplished within 19 days (15 fractions). Dose volume histograms, calculated for tissue specific alpha/beta ratios and time factors, predict a high biological dose to the prostate and seminal vesicles (77-93 Gy). The biological dose to normal pelvic tissues is maintained at standard levels. Radiobiological dosimetry suggests that, using hypofractionated and accelerated radiotherapy, high biological radiation dose can be given to the prostate without overdosing normal tissues.