Secondary radiation dose during high-energy total body irradiation.

AIM: The goal of this work was to assess the additional dose from secondary neutrons and γ-rays generated during total body irradiation (TBI) using a medical linac X-ray beam. BACKGROUND: Nuclear reactions that occur in the accelerator construction during emission of high-energy beams in teleradiotherapy are the source of secondary radiation. Induced activity is dependent on the half-lives of the generated radionuclides, whereas neutron flux accompanies the treatment process only. MATERIALS AND METHODS: The TBI procedure using a 18 MV beam (Clinac 2100) was considered. Lateral and anterior-posterior/posterior-anterior fractions were investigated during delivery of 2 Gy of therapeutic dose. Neutron and photon flux densities were measured using neutron activation analysis (NAA) and semiconductor spectrometry. The secondary dose was estimated applying the fluence-to-dose conversion coefficients. RESULTS: The main contribution to the secondary dose is associated with fast neutrons. The main sources of γ-radiation are the following: (56)Mn in the stainless steel and (187)W of the collimation system as well as positron emitters, activated via (n,γ) and (γ,n) processes, respectively. In addition to 12 Gy of therapeutic dose, the patient could receive 57.43 mSv in the studied conditions, including 4.63 µSv from activated radionuclides. CONCLUSION: Neutron dose is mainly influenced by the time of beam emission. However, it is moderated by long source-surface distances (SSD) and application of plexiglass plates covering the patient body during treatment. Secondary radiation gives the whole body a dose, which should be taken into consideration especially when one fraction of irradiation does not cover the whole body at once.

Using fiducial markers in the prostate bed in postprostatectomy external beam radiation therapy improves accuracy over surgical clips.

BACKGROUND AND PURPOSE: The purpose of this work was to assess the stability of fiducial markers in the prostate bed and compared their use to surgical clips. PATIENTS AND METHODS: In this study, 3-4 gold fiducial markers were transrectally implanted in the prostate bed of 14 patients. The stability of the fiducial markers position (fiducial markers fixity) over an EBRT course was assessed. Furthermore, the advantages of the fiducial markers compared to the surgical clips were assessed and the interobserver variation between the two technologies was compared. RESULTS: The mean fiducial marker migration during a course of EBRT was small with 1.2 mm (SD ± 0.8 mm). Compared to fiducial markers, the matches with surgical clips were mismatched ≥ 2 mm in 68% of treatments. This discrepancy of > 2 mm was on average 3.7 ± 1.3 mm. There was less interobserver variability for matching of fiducial markers (0.8 ± 0.7 mm) than for surgical clips (2.0 ± 1.6 mm). CONCLUSION: Fiducial markers showed less interobserver variability in matching and less variation in position than surgical clips. Fiducial markers could ultimately help in reducing treatment margins.

Adaptive off-line protocol for prostate external radiotherapy with cone beam computer tomography.

PURPOSE: The goal of this work was to prepare and to evaluate an off-line adaptive protocol for prostate teleradiotherapy with kilovoltage cone beam computer tomography (CBCT). PATIENTS AND METHODS: Ten patients with localized prostate carcinoma treated with external beams underwent image-guided radiotherapy. In total, 162 CBCT images were collected. Position of prostate and pubis symphysis (PS) with respect to the isocenter were measured off-line. Using the CBCT scans obtained in the first three fractions the average position of prostate in relation (AvPosPr) to PB was calculated. On each CBCT scan, the position of prostate with respect to AvPosPr was calculated and cumulative histogram of prostate displacement with respect to AvPosPr was prepared. Using this data, the adaptive protocol was prepared in which (1) based on the CBCT made in the first three fractions the AvPosPr to PS is obtained, (2) in all other fractions two orthogonal images are acquired and if for any direction set-up error exceeds 0.2 cm the patient's position is corrected, and (3) additionally, the patient's position is corrected if the AvPosPr exceeds 0.2 cm in any direction. To evaluate the adaptive protocol for 30 consecutive patients, the CBCT was also made in 10th and 21st fraction. RESULTS: For the first 10 patients, the results revealed that the prostate was displaced in relation to AvPosPr >0.7 cm in the vertical and longitudinal directions only on 4 and 5 images of 162 CBCT images, respectively. For the lateral direction, this displacement was >0.3 cm in one case. For the group of 30 patients, displacement was never >0.7, and 0.3 cm for the vertical and lateral directions. In two cases, displacements were >0.7 cm for the longitudinal direction. CONCLUSION: Implementation of the proposed adaptive procedure based on the on-line set-up error elimination followed by a reduction of systematic internal error enables reducing the CTV-PTV margin to 0.7, 0.7, and 0.4 cm for the vertical, longitudinal, and lateral directions, respectively.

Aperture superposition dose model versus pencil beam superposition dose model for a finite size Cobalt-60 source for tomotherapy deliveries.

PURPOSE: The finite size pencil beam (FSPB) superposition method is a commonly used dose calculation method in intensity modulated radiation therapy (IMRT). The FSPB model assumes that dose for a broad intensity modulated beam can be calculated by superposition of dose from small, pencil-like beams. However, this model is limited to point-like radiation sources and is not valid for finite size sources, such as a Cobalt-60 (Co-60) source of 2 cm diameter. In this paper, the authors present results that show the limitation of this model and propose an alternative model, namely the aperture superposition (AS) model, to calculate photon dose for intensity modulated beams arising from finite size radiation sources. METHODS: The AS model is based on adding beam apertures rather than pencil beams. Each aperture is defined as a series of adjacently opened leaves of a multileaf collimator with no closed leaves in between them. The apertures are calculated using the EGSnrc Monte Carlo program. The accuracy of the AS model was tested for dose calculations of fan beams, as encountered in tomotherapy treatment plans. The results were compared with the FSPB model and GafChromic film measurements. The measurements and simulations were performed for a clinical Theratronics T780C Co-60 unit with MIMiC binary multileaf collimator mounted on it. RESULTS: The comparisons between the AS model and film measurements show agreement better than 1.5% in the high dose regions and 3.7% in the low dose regions. On the contrary, film measurement comparisons to the FSPB model show that the FSPB model underestimates the dose by up to 7% for small field sizes such as 2 × 2 cm(2) and 20% for larger field sizes such as 20 × 2 cm(2). CONCLUSIONS: The results presented in this paper indicate that the AS model provides better accuracy than the FSPB model when calculating dose for fan beams from large radiation sources. The implementation of this model to the current treatment planning systems has the scope of advancing Co-60 based IMRT and tomotherapy.

Pattern of oncologic emergencies seen in adult cancer patients attending the Radiotherapy and Oncology Centre, Ahmadu Bello University Teaching Hospital, Zaria - Nigeria.

AIMS AND OBJECTIVES: To evaluate the Pattern of Oncologic Emergencies seen in Adult cancer patients and the treatment modalities used. MATERIALS AND METHODS: Between January 2004 and December 2008, a total of 1824 (M:F = 1:1.8) new patients were seen. 196 (M:F = 1:1.4) consecutive patients with histologically confirmed malignancies presenting with or having oncologic emergencies were treated and have been reviewed. Patients' folders were reviewed retrospectively with a structured pro forma. Results were analysed using Epi Info soft ware Version 3.4.1; 2007 Edition. RESULTS: The median age was 49 years and mean age of 42 years (range, 15 - 82 years). M: F = 1:1.4. 162 patients had oncologic emergencies at presentation while 21 during treatments and 13 during follow up. At the time of diagnosis of oncologic emergency, 126 were not on any treatment, 42 patients on hormonal therapy and 28 patients were on diverse chemotherapy. All the patients presented late with 108 patients presenting with metastatic disease and 88 patients with locally advanced disease. Only 35 patients were treated within 1 week of onset of emergency. 59 patients had cervical cancer, 31 patients with breast cancer and 28 patients with prostate cancer. Tumour haemorrhage wass the commonest oncologic emergency seen in 107 patients followed by bone pain with imminent cord compression from bone metastases in 59 patients. Of 107 patients with tumour haemorrhage, 54 patients had cardiovascular collapse with 7 having acute renal failure. Similarly, of the 107 with tumour haemorrhage, 56 patients bled from cervical cancer, 12 patients from breast cancer and 8 patients from urinary bladder. 129 patients were treated with teletherapy, 31 patients had chemotherapy, 27 patients had emergency surgery and 5 patients had chemoradiation. Oncologic emergencies were corrected in 126 patients. CONCLUSION: Tumour haemorrhage is the commonest oncologic emergency in this environment and teletherapy is the commonest therapy used. More radiotherapy centres are needed for prompt treatment and their usefulness in managing emergencies should be made known. Oncologic emergencies are commonly seen in metastatic and locally advanced disease.

Radiotherapy of splenomegaly : a palliative treatment option for a benign phenomenon in malignant diseases.

PURPOSE: Since the 20(th) century, radiotherapy (RT) has been used for treatment of symptomatic splenomegaly (SM). SM occurs in association with hematologic disorders. The purpose of this analysis was to determine the indication, treatment concepts, and efficiency of RT. MATERIAL AND METHODS: Clinical features, treatment concepts, and outcome data during the past 20 years were analyzed. Endpoints were pain relief, symptomatic and hematological response, and treatment-related side effects. RESULTS: From 1989-2009, a total of 122 patients received 246 RT courses because of symptomatic SM. Overall 31 patients had chronic myelogenous leukemia (CML), 37 had chronic lymphocytic leukemia (CLL), 23 had osteomyelofibrosis (OMF), 17 had polycythemia vera (PV), 5 had acute myelogenous leukemia, 4 had idiopathic thrombocytopenic purpura (ITP), 3 had non-Hodgkin lymphoma (NHL), and 2 had multiple myeloma (MM). Patients were treated with (60)Co gamma rays or 5-15MV photons. The fraction size ranged from 10-200 cGy and the total dose per treatment course from 30-1600 cGy. Significant pain relief was achieved for 74.8% of the RT courses given for splenic pain. At least 50% regression was attained for 77% of the RT courses given for SM. 36 patients died within 2 months due to the terminal nature of their disease. Of the RT courses applied for cytopenia, 73.6% achieved a significant improvement of hematological parameters and reduction of transfusion need. Notable hematologic toxicities were reported < EORTC/RTOG II°. CONCLUSION: The present analysis documents the efficacy of RT. In addition, RT as a palliative treatment option for symptomatic SM should not be forgotten.

Dosimetric evaluation of high-dose-rate interstitial brachytherapy boost treatments for localized prostate cancer.

PURPOSE: To quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. MATERIAL AND METHODS: Treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D(min)) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D(r)) and urethra (D(u)), dose to volume of 2 cm(3) of the rectum (D(2ccm)), and 0.1 cm(3) and 1% of the urethra (D(0.1ccm) and D1) were determined. Nonparametric correlation analysis was performed between these parameters. RESULTS: The median number of needles was 16, the mean prostate volume (V(p)) was 27.1 cm(3). The mean V90, V100, V150, and V200 were 99%, 97%, 39%, and 13%, respectively. The mean D90 was 109%, and the D(min) was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D(2ccm) = 49% for the rectum, D(0.1ccm) = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D(r),D(2ccm)) = 0.69, R(D(u),D0.(1ccm)) = 0.64, R(D(u),D1) = 0.23. CONCLUSION: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric parameter is recommended.

Radiotherapeutic management of laryngeal carcinoma.

Authors discuss laryngeal lesions, metastases, and relevant anatomy. Outcome of surgical and radiotherapy in terms of voice preservation is discussed. Radiation techniques and outcomes for laryngeal cancer are presented along with discussion of interdisciplinary treatment. Authors review studies and quality of life outcomes of surviving laryngeal cancer patients.

[Treatment of clinically localized prostate cancer. Part III--external beam radiotherapy]. / Leczenie klinicznie zlokalizowanego raka gruczolu krokowego. Czesc III--teleradioterapia.

The optimal management of clinically localized (T1, T2) prostate cancer remains controversial. Patients have possibility of choice between prostatectomy and radiotherapy in two forms: external beam radiotherapy and brachytherapy. Multicentre studies show comparable results of theise two methods. The aim of this paper is to present current knowledge regarding treatment with conformal radiotherapy. Acute and late effects of ionizing radiation are described. Propriety of associate radiotherapy with hormonotherapy was analyzsed.

[Assessment of radiation injuries to the salivary glands after treatment of head and neck cancers]. / Ocena wystepowania póznego odczynu popromiennego w obrebie slinianek po napromienianiu nowotworów glowy i szyi.

PURPOSE: The purpose of this investigation was to evaluate the quality of life, measured in LENT-SOMA and DISCHE scale, of patients with xerostomia as late irradiation injury. MATERIALS AND METHODS: 45 head and neck cancer patients were radically irradiated receiving doses from 48 Gy to 76.8 Gy (mean: 65.1 Gy) on PTV. Patients received doses from 48 to 76 Gy on salivary gland (mean: 63.8 Gy, SD: 8). The irradiation injury of the oral cavity was assessed using DISCHE scale at the end of radiotherapy and late radiation sequels of salivary gland was assessed in 6 and 7 month after radiotherapy using DISCHE and LENT-SOMA scale. The average follow-up for this group of patients was 8 months. RESULTS: All patients with 6 and more points of acute reactions assessed in DISCHE scale at the end of radiotherapy have had xerostomia in follow-up period. Results measured by LENT-SOMA scale was similar to DISCHE scale. CONCLUSIONS: Dose escalation of radiotherapy increases number of xerostomia as late irradiation injury. Both scales (LENT-SOMA and DISCHE) are similar in qualifying and quantifying of salivary gland radiation injury. Minimal therapeutic dosage prescribed on salivary gland after which irradiation injury occurred was 63 Gy.

Physical characterization of single convergent beam device for teletherapy: theoretical and Monte Carlo approach.

The main purpose of this work is to determine the feasibility and physical characteristics of a new teletherapy device of radiation therapy based on the application of a convergent x-ray beam of energies like those used in radiotherapy providing highly concentrated dose delivery to the target. We have denominated it Convergent Beam Radio Therapy (CBRT). Analytical methods are developed first in order to determine the dosimetry characteristic of an ideal convergent photon beam in a hypothetical water phantom. Then, using the PENELOPE Monte Carlo code, a similar convergent beam that is applied to the water phantom is compared with that of the analytical method. The CBRT device (Converay(®)) is designed to adapt to the head of LINACs. The converging beam photon effect is achieved thanks to the perpendicular impact of LINAC electrons on a large thin spherical cap target where Bremsstrahlung is generated (high-energy x-rays). This way, the electrons impact upon various points of the cap (CBRT condition), aimed at the focal point. With the X radiation (Bremsstrahlung) directed forward, a system of movable collimators emits many beams from the output that make a virtually definitive convergent beam. Other Monte Carlo simulations are performed using realistic conditions. The simulations are performed for a thin target in the shape of a large, thin, spherical cap, with an r radius of around 10-30 cm and a curvature radius of approximately 70 to 100 cm, and a cubed water phantom centered in the focal point of the cap. All the interaction mechanisms of the Bremsstrahlung radiation with the phantom are taken into consideration for different energies and cap thicknesses. Also, the magnitudes of the electric and/or magnetic fields, which are necessary to divert clinical-use electron beams (0.1 to 20 MeV), are determined using electromagnetism equations with relativistic corrections. This way the above-mentioned beam is manipulated and guided for its perpendicular impact upon the spherical cap. The first results that were achieved show in-depth dose peaks, having shapes qualitatively similar to those from hadrontherapy techniques. The obtained results demonstrate that in-depth dose peaks are generated at the focus point or isocenter. These results are consistent with those obtained with Monte Carlo codes. The peak-focus is independent of the energy of the photon beam, though its intensity is not. The realistic results achieved with the Monte Carlo code show that the Bremsstrahlung generated on the thin cap is mainly directed towards the focus point. The aperture angle at each impact point depends primarily on the energy beam, the atomic number Z and the thickness of the target. There is also a poly-collimator coaxial to the cap or ring with many holes, permitting a clean convergent-exit x-ray beam with a dose distribution that is similar to the ideal case. The electric and magnetic fields needed to control the deflection of the electron beams in the CBRT geometry are highly feasible using specially designed electric and/or magnetic devices that, respectively, have voltage and current values that are technically achievable. However, it was found that magnetic devices represent a more suitable option for electron beam control, especially at high energies. The main conclusion is that the development of such a device is feasible. Due to its features, this technology might be considered a powerful new tool for external radiotherapy with photons.

Experimental dosimetry in conformal breast teletherapy compared with the planning system.

The objective of this study was to compare and analyse the absorbed dose profiles from the conformal radiotherapy planning and experimental dosimetry taken in a breast anthropomorphic and anthropometric phantom. Conformal radiotherapy planning was elaborated in the Treatment Planning System (TPS). EBT2 Gafchromic radiochromic films were applied as dosimeters, positioned internally and superficially in the breast phantom. The standard radiation protocol was applied in the breast phantom. The films were digitalised, and their responses were analysed in RGB. The optical densities were processed, reproducing the spatial dose distribution.

A modified 60C teletherapy unit for total body irradiation.

PURPOSE: A modified teletherapy unit to achieve total body irradiation with a vertical beam in a conventional treatment room. METHODS AND MATERIALS: A standard 60C teletherapy unit has been modified to achieve total body irradiation with a vertical beam in a conventional treatment room. Patients are treated in prone and supine positions. Removal of the adjustable collimator assembly of this standard machine provides a circular field of 196 cm in diameter at 167 cm from the source. Second, the machine has been elevated by about 50 cm on a metallic base to enlarge irradiation field to obtain 248 cm in diameter at 210 cm from the source, and to encompass tall patients under better conditions. A special lead conical beam flattening filter, 10-mm thick at the center, was designed to compensate the spatial inhomogeneity of the beam. An instantaneous dose rate of 6.10(-2) Gy/min is attained at the L4 level (midplane) in an average 20-cm thick patient with a source activity of 5099 RHM (air kerma rate of 44.8 Gy.h-1.m2). Between February 2, 1984 and December 27, 1990, 244 total body irradiations were performed either by single dose (n = 69, 10 Gy were given to midplane at L4 level in about 6 to 8 h, 8 Gy to the lungs), or by fractionated dose (n = 175, 12 Gy were given in 6 fractions over 3 consecutive days to midplane at L4 level, 9 Gy to the lungs). RESULTS: The dose distribution is similar than the ones obtained by a linear accelerator with patients lying on their sides. CONCLUSION: Patients were treated in a comfortable and highly reproductible position. Organ shielding was easily achievable. This could be a less expensive and reasonable alternative to linear accelerator.

Feasibility of insertion/implantation of 2.0-mm-diameter gold internal fiducial markers for precise setup and real-time tumor tracking in radiotherapy.

PURPOSE: To examine the feasibility and reliability of insertion of internal fiducial markers into various organs for precise setup and real-time tumor tracking in radiotherapy (RT). MATERIALS AND METHODS: Equipment and techniques for the insertion of 2.0-mm-diameter gold markers into or near the tumor were developed for spinal/paraspinal lesions, prostate tumors, and liver and lung tumors. Three markers were used to adjust the center of the mass of the target volume to the planned position in spinal/paraspinal lesions and prostate tumors (the three-marker method). The feasibility of the marker insertion and the stability of the position of markers were tested using stopping rules in the clinical protocol (i.e., the procedure was abandoned if 2 of 3 or 3 of 6 patients experienced marker dropping or migration). After the evaluation of the feasibility, the stability of the marker positions was monitored in those patients who entered the dose-escalation study. RESULTS: Each of the following was shown to be feasible: bronchoscopic insertion for the peripheral lung; image-guided transcutaneous insertion for the liver; cystoscopic and image-guided percutaneous insertion for the prostate; and surgical implantation for spinal/paraspinal lesions. Transcutaneous insertion of markers for spinal/paraspinal lesions and bronchoscopic insertion for central lung lesions were abandoned. Overall, marker implantation was successful and was used for real-time tumor tracking in RT in 90 (90%) of 100 lesions. No serious complications related to the marker insertion were noted for any of the 100 lesions. Using three markers surgically implanted into the vertebral bone, the mean +/- standard deviation in distance among the three markers was within 0.2 +/- 0.6 mm (range -1.4 to 0.8) through the treatment period of 30 days. The distance between the three markers gradually decreased during RT in five of six prostate cancers, consistent with a mean rate of volume regression of 9.3% (range 0.015-13%) in 10 days. CONCLUSIONS: Internal 2.0-mm-diameter gold markers can be safely inserted into various organs for real-time tumor tracking in RT using the prescribed equipment and techniques. The three-marker method has been shown to be a useful technique for precise setup for spinal/paraspinal lesions and prostate tumors.

Dose evaluation to patients irradiated by 60Co beams, by means of direct measurement on the incident and on the exit surfaces.

A method for direct dose measurements on a patient treated with 60Co beams, is described. A home-made multi-probe dosimeter with silicon diodes as detectors is described. Measurements were performed on the entrance as well as on the exit fields, and a correlation was established with the mid-line dose. The influence of field size, SSD, patient thickness, and inhomogeneities was investigated.

Radiation therapy of ovarian carcinoma: presentation of a six-field technique.

A new technique for radiotherapy in ovarian carcinoma is presented. The aim was to deliver a homogeneous radiation dose to the entire abdominal cavity. The whole abdomen, except for 20% of the upper compartment, received a homogeneous dose of 40 Gy, while 2/3 of the kidneys and the posterior part of the liver received a dose ranging from 40 to 20 Gy. No clinically significant impairment of liver function was seen during follow-up.

The use of a concomitant electron boost (field in the field technique) in large cervical node metastases over a shortened period.

Seven patients with large cervical node metastases were treated at the Institut Jean-Godinot using a particular scheme of accelerated irradiation. Conventional Cobalt-60 radiotherapy was prophylactically delivered to extended volumes of the neck (50 Gy in 25 fractions over 5 weeks). Within the fields of cobalt irradiation, an electron beam field was added to increase the daily dose from 2 to 3 Gy (Fletcher's field in the field technique). The increment of dose was limited to nodal area. Since no interval separated the two irradiations, involved areas were considered to receive 70 Gy in 25 fractions over 5 weeks and non-clinically involved areas to receive 50 Gy in 25 fractions over 5 weeks. In all the cases, the malignant mass diameter exceeded 5 cm. Acute tolerance was good and no major late injury was observed during the 18 months minimum follow-up period. At the end of the treatment, a complete disappearance of the tumor was observed in six out of seven cases. At the present time, four patients are still alive without evidence of disease. Slight acceleration of irradiation by the use of a concomitant electron boost is easily feasible and may provide an improvement in local control and therapeutic ratio of large cervical malignant masses in the neck.

Preoperative radiation therapy in advanced carcinoma of the ovary.

Preoperative radiotherapy in advanced ovarian carcinoma was evaluated. The overall 5-year survival rate in the irradiated group was 27%. When tumour mass remaining after operation was less than 2 cm in diameter, this figure rose to 52%. Comparison was made between those in whom operation became feasible only after preoperative irradiation and patients in advanced stages who were primarily successfully operated to less than 2 cm and with a 5-year survival rate of 44%. Selection of the cases for preoperative radiotherapy is obviously necessary. Fixed, bulky tumours in the pelvis, with or without metastases, may be suitable for preoperative radiotherapy.

Conservative treatment for breast cancer: long-term results (15 years).

From 1961 to 1974, 245 patients with unilateral "operable" breast cancer (25% T1, 56% T2, 19% T3) were treated with breast conservation and irradiation at the Gustave Roussy Institute (1961-1969) or at the Henri Mondor Hospital (1970-1974). The minimum follow-up is 15 years. Most patients with T greater than 3 cm underwent radiation therapy with the tumor in place, while the greater part of patients with T less than 3 cm received radiation therapy after tumorectomy. The breast and draining lymph node areas received widefield telecobalt irradiation to 45 Gy. The dose to the tumor site was boosted using iridium-192 implantation. Additional irradiation was given to the internal mammary and lower axillary nodes using an electron beam. The 15 years NED survival rate was 63%, 51% and 26% for T1, T2 and T3 tumors, respectively. The NED survival for T less than or equal to 1 cm was 86%. The local recurrence rate was 8, 12 and 19% for T1, T2 and T3 tumors, respectively. Of the patients with local recurrence, 85% underwent surgical salvage. Complications were rare. Cosmetic results were satisfactory in most patients including the T3 group. The proportion of breasts conserved among patients living NED at 15 years, was 97, 88 and 93% for T1, T2 and T3 tumors, respectively. In 1980, after almost 20 years experience using breast conserving techniques, we modified our treatment policies in close collaboration with our surgical team, hel cbye extending the indications for tumorectomy and associating routine surgical exploration of the lower axilla.