Ioannis Abatzoglou

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.

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.

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 8th 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.

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.

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.

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.

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.

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 × 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.

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.