The Role of Adjuvant Radiotherapy for a Case of Primary Breast Sarcoma: A Plan Comparison between Three Modern Techniques and a Review of the Literature.

A 65-year-old woman, affected by a malignant fibrous histiocytoma (undifferentiated pleomorphic sarcoma) of the left breast, presented to our department to receive the postoperative radiotherapy. In the absence of prospective and randomized trials and investigations on breast sarcoma irradiation in literature, due to the rarity of this pathology, the role of adjuvant radiotherapy remains unclear. To identify the best radiotherapy technique for this patient, three methods were compared: 3D conformal radiotherapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and volumetric arc therapy (VMAT) or RapidArc® (RA). 50 Gy was prescribed to the chest wall and 66 Gy to the tumor bed. Three plans were designed, and target coverage, organs-at-risk sparing, and treatment efficiency were compared. IMRT and RA improved both target coverage and dose uniformity/homogeneity. Planning objective for the lung is always satisfied comparing the different techniques, but the volume receiving 20 Gy drops to 17% by RA compared to 3D-CRT. The heart volume receiving 30 Gy was 10% by IMRT, against 13% and 16% by RA and 3D-CRT. The monitor unit (MU) required by 3D-CRT was 527 MU, followed by RA and IMRT. Treatment time was similar with 3D-CRT and RA but doubled using IMRT. Although all three radiotherapy techniques offered a satisfactory solution, RA and IMRT offer some improvement on target coverage, dose homogeneity, and conformity for this particular case of breast sarcoma.

A radiotherapy technique for palliative total scalp irradiation.

A scalp irradiation technique for palliative treatment of a squamous cell carcinoma was discussed. A patient with multiple cutaneous scalp lesions resulting in bleeding and pain was treated with a 3D conformal radiotherapy technique was performed with five 6 MV electron beams without shifting the field borders during the course of the treatment, due to the finality of the treatment (palliative intent). A reduction of planning and delivery complexity has been obtained not considering the junctioning problems. Nevertheless, the 90% of gross tumor volume (GTV) was covered by the 85% of prescription dose with a significant reduction of patient's symptoms (pain and bleeding). Our patient achieved a significant pain response and resolution of bleeding with this technique. Our study revealed that the scalp irradiation by means of electron beam without considering the junction problem is easy and effective for the palliative intent in elderly patients with squamous cell carcinoma.

Twenty years of radiobiology in clinical practice: the Italian contribution.

AIMS AND BACKGROUND: To present the Italian state-of-the-art contribution to radiobiology of external beam radiotherapy, brachytherapy, and radionuclide radiotherapy. METHODS AND STUDY DESIGN: A survey of the literature was carried out, using PubMed, by some independent researchers of the Italian group of radiobiology. Each paper was reviewed by researchers of centers not comprising its authors. The survey was limited to papers in English published over the last 20 years, written by Italian investigators or in Italian institutions, excluding review articles. RESULTS: A total of 135 papers have been published in journals with an impact factor, with an increase in the number of published papers over time, for external beam radiotherapy rather than radionuclide radiotherapy. The quantity and quality of the papers researched constitutes a proof of the enduring interest in clinical radiobiology among Italian investigators. CONCLUSIONS: The survey could be useful to individuate expert partners for an Italian network on clinical radiobiology, addressing future collaborative investigations.

Is ExacTrac x-ray system an alternative to CBCT for positioning patients with head and neck cancers?

PURPOSE: To evaluate the usefulness of a six-degrees-of freedom (6D) correction using ExacTrac robotics system in patients with head-and-neck (HN) cancer receiving radiation therapy. METHODS: Local setup accuracy was analyzed for 12 patients undergoing intensity-modulated radiation therapy (IMRT). Patient position was imaged daily upon two different protocols, cone-beam computed tomography (CBCT), and ExacTrac (ET) images correction. Setup data from either approach were compared in terms of both residual errors after correction and punctual displacement of selected regions of interest (Mandible, C2, and C6 vertebral bodies). RESULTS: On average, both protocols achieved reasonably low residual errors after initial correction. The observed differences in shift vectors between the two protocols showed that CBCT tends to weight more C2 and C6 at the expense of the mandible, while ET tends to average more differences among the different ROIs. CONCLUSIONS: CBCT, even without 6D correction capabilities, seems preferable to ET for better consistent alignment and the capability to see soft tissues. Therefore, in our experience, CBCT represents a benchmark for positioning head and neck cancer patients.

Local tumor control probability to evaluate an applicator-guided volumetric-modulated arc therapy solution as alternative of 3D brachytherapy for the treatment of the vaginal vault in patients affected by gynecological cancer.

The purpose of this study was to evaluate the applicator-guided volumetric-modulated arc therapy (AGVMAT) solution as an alternative to high-dose-rate brachytherapy (HDR-BRT) treatment of the vaginal vault in patients with gynecological cancer (GC). AGVMAT plans for 51 women were developed. The volumetric scans used for plans were obtained with an implanted CT-compatible vaginal cylinder which provides spatial registration and immobilization of the gynecologic organs. Dosimetric and radiobiological comparisons for planning target volume (PTV) and organs at risk (OARs) were performed by means of a dose-volume histogram (DVH), equivalent uniform dose (EUD), and local tumor control probability (LTCP). In addition, the integral dose and the overall delivery time, were evaluated. The HDR-BRT averages of EUD and minimum LTCP were significantly higher than those of AGVMAT. Doses for the OARs were comparable for the bladder and sigmoid, while, although HDR-BRT was able to better spare the bowel, AGVMAT provided a significant reduction of d2cc, d1cc, and dmax (p < 0.01) for the rectum. AGVMAT integral doses were higher than HDR-BRT with low values in both cases. Delivery times were about two or three times higher for HDR-BRT with respect to the single arc technique (AGVMAT1) and dual arc technique (AGVMAT2), respectively. The applicator-guided volumetric-modulated arc therapy seems to have the potential of improving rectum avoidance. However, brachytherapy improves performance in terms of PTV coverage, as demonstrated by a greater EUD and better LTCP curves.

Comparative dosimetric and radiobiological assessment among a nonstandard RapidArc, standard RapidArc, classical intensity-modulated radiotherapy, and 3D brachytherapy for the treatment of the vaginal vault in patients affected by gynecologic cancer.

To evaluate a nonstandard RapidArc (RA) modality as alternative to high-dose-rate brachytherapy (HDR-BRT) or IMRT treatments of the vaginal vault in patients with gynecological cancer (GC). Nonstandard (with vaginal applicator) and standard (without vaginal applicator) RapidArc plans for 27 women with GC were developed to compare with HDR-BRT and IMRT. Dosimetric and radiobiological comparison were performed by means of dose-volume histogram and equivalent uniform dose (EUD) for planning target volume (PTV) and organs at risk (OARs). In addition, the integral dose and the overall treatment times were evaluated. RA, as well as IMRT, results in a high uniform dose on PTV compared with HDR-BRT. However, the average of EUD for HDR-BRT was significantly higher than those with RA and IMRT. With respect to the OARs, standard RA was equivalent of IMRT but inferior to HDR-BRT. Furthermore, nonstandard RA was comparable with IMRT for bladder and sigmoid and better than HDR-BRT for the rectum because of a significant reduction of d(2cc), d(1cc), and d(max) (p < 0.01). Integral doses were always higher than HDR-BRT, although the values were very low. Delivery times were about the same and more than double for HDR-BRT compared with IMRT and RA, respectively. In conclusion, the boost of dose on vaginal vault in patients affected by GC delivered by a nonstandard RA technique was a reasonable alternative to the conventional HDR-BRT because of a reduction of delivery time and rectal dose at substantial comparable doses for the bladder and sigmoid. However HDR-BRT provides better performance in terms of PTV coverage as evidenced by a greater EUD.

Effective and equivalent organ doses in patients undergoing coronary angiography and percutaneous coronary intervention.

PURPOSE: Recent recommendations of the International Commission on Radiological Protection state that the use of effective dose (E) for assessing patient exposure has severe limitations, though it can be kept for dose comparisons. In cardiology procedures, the equivalent dose (H(T)) is one of the most appropriate dose quantity to be evaluated for risk-benefit assessment. In this study, both E and H(T) values for ten critical organs in coronary angiography (CA) and percutaneous coronary interventions (PCI) were derived from in-the-field dose-area-product (DAP) measurements in order to provide a database for doses in those procedures. METHODS: Conversion factors E/DAP calculated by Monte Carlo methods in two different mathematical human phantoms were applied to DAP values measured on 193 patients (118 CA and 75 PCI). Partial DAP values were recorded in-the-field for each projection and for all patients. The partial effective doses of all projections were summed up to calculate the E of the entire procedure. Similarly, equivalent doses for ten critical organs/tissues (bone, colon, heart, liver, lung, esophagus, red bone marrow, skin, stomach, and thyroid) were derived from H(T)/DAP conversion factors for different projections calculated by Monte Carlo method. RESULTS: All parameters related to the patient dose, i.e., fluoroscopy times, number of images, DAP, effective doses, and equivalent doses, show a wide range of values depending on the complexity of the patient case and the experience of the cardiologist. The mean fluoroscopy time, DAP, and E values for coronary angiography patients were approximately threefold lower than those for PCI patients; the number of images for CA was half that for PCI. The correlation between effective dose and DAP was excellent for both CA and PCI. The equivalent doses values were in good correlations with DAP values in CA examinations, with Pearson's coefficients ranging from 0.87 (stomach) to 0.99 (skin) and r(mean) = 0.94. The same analysis was performed for PCI procedures. In this case, the trends were only slightly worse because "r" ranged from 0.70 (stomach) to 0.92 (bone) and r(mean) = 0.85. Simple conversion coefficients to estimate equivalent doses to ten critical organs/tissues from DAP values, for both CA and PCI, were provided for avoiding the need to carry out detailed in-the-field analysis for all projections and for all patients. CONCLUSIONS: Measurements in-the-field of DAP values were carried out for two common cardiology procedures and effective doses were derived for each technique from detailed analysis of dose and projection data, using conversion factors provided by two different theoretical models. Equivalent doses to organs/tissues were also calculated using conversion factors proposed in the literature for different projections and cumulative conversion factors (H)T/DAP for ten organs/tissues were estimated.