Phase II study on the use of intraoperative radiotherapy in early breast cancer

To report our early experience using the Intrabeam radiotherapy delivery system for intraoperative radiotherapy [IORT] in early breast cancer. This is a prospective phase 2 study carried out at the Department of Surgery and Radiology, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia from December 2010 to November 2012. Females eligible for breast-conserving surgery with biopsy-proven invasive duct carcinoma, and with a mass of 3 cm, with lymphovascular invasion, multifocal lesion, extensive intraductal carcinoma, and positive nodes. Early and late toxicity were recorded using the Radiation Therapy Oncology Group [RTOG] criteria. Forty-five patients were included with a median age of 54 [range: 27-79 years]. Thirty-six cases [80%] had tumor <3 cm in diameter, and 36 [67%] have pathologically negative axillary lymph node metastases. None of the patients developed delayed wound healing, postoperative infection requiring intravenous antibiotic, or breast seroma requiring aspiration. Sixteen [36%] received EBRT after IORT. Twelve patients developed radiologically proved fat necrosis. The IORT for early stage breast cancer patients using the Intrabeam delivery system was easily implemented in our center with an acceptable toxicity profile and cosmetic outcome

Tumor bed boost radiotherapy in breast cancer. A review of current techniques

Various breast boost irradiation techniques were studied and compared. The most commonly used techniques are external beam radiation therapy [EBRT] [photons or electrons] and high dose rate [HDR] interstitial brachytherapy, but recent studies have also revealed the use of advanced radiotherapy techniques, such as intensity modulated radiation therapy [IMRT], intra-operative radiation therapy [IORT], tomotherapy, and protons. The purpose of this study is to systematically review the literature concerning breast boost radiotherapy techniques, and suggest evidence based guidelines for each. A search for literature was performed in the National Library of Medicine's [PubMed] database for English-language articles published from 1st January 1990 to 5th April 2011. The key words were `breast boost radiotherapy`, `breast boost irradiation`, and `breast boost irradiation AND techniques`. Randomized trials comparing the long-term results of boost irradiation techniques, balancing the local control, and cosmesis against logistic resources, and including cost-benefit analysis are further needed

Three-dimension anatomy-based planning optimization for high dose rate vaginal vault brachytherapy

To retrospectively compare 3-dimension [3D]-inverse planning optimization with 2 conventional planning methods in vaginal vault high-dose-rate brachytherapy. We randomly selected 26 patients with endometrium cancer, treated with external beam radiotherapy followed by intracavitary high-doserate brachytherapy. The study was carried out in the Radiotherapy Unit of King Abdulaziz University Hospital, Jeddah, Saudi Arabia between July 2010 and October 2011. For each brachytherapy fraction, dosevolume-histograms were analyzed for 3 different dose prescription protocols: 0.5 cm from the applicator's tip, 0.5 cm along the applicator's surface, and inverse planning. Dose-volume-histogram analysis showed a significant difference [p<0.001] between the 3 treatment planning methods regarding clinical-targetvolume prescribed dose coverage: 26.7% +/- 5.4% versus 48.5% +/- 6.7% versus 68.6% +/- 7.5%. The doses received by the volumes of 2 cm[3] of organs-at-risk were [p<0.001]: rectum: 4.6 +/- 1.1 Gy versus 2.8 +/- 0.5 Gy versus 3.3 +/- 0.5 Gy; sigmoid: 1.4 +/- 0.8 Gy versus 0.7 +/- 0.3 Gy versus 0.9 +/- 0.5 Gy; and bladder: 3.7 +/- 1.0 Gy versus 2.3 +/- 0.5 Gy, versus 2.7 +/- 0.6 Gy. Three-dimension inverse planning provides the ability to balance the target dose coverage against the sparing of organs at risk. For vaginal vault high-dose-rate inverse planning brachytherapy, the use of a CT scan only for the first fraction of treatment is feasible, and the dosimetric impact is minimal.

Treatment planning for high dose rate brachytherapy of cervical cancer based on total dose constraints

To compare the inverse planning optimization based on total dose constraints versus conventional treatment plan [point A planning method] for cervical carcinoma, and evaluate the benefit of CT-based image-guided brachytherapy. We prospectively analyzed data of 10 consecutive patients with cervical cancer treated with external beam radiotherapy to the whole pelvis [45 Gy in 25 fractions] followed by high-dose-rate [HDR] brachytherapy [21 Gy in 3 fractions]. For treatment planning of HDR brachytherapy, the basic equations of the linear-quadratic model were used to calculate the physical dose for each brachytherapy fraction needed to achieve a given total iso-effective dose for the whole treatment. Specific dosimetric parameters are evaluated for high risk [HR CTV], intermediate risk [IR CTV] clinical target volumes, and organs at risk [OARs]. In conventional plans, the HR CTV was well covered in only 15/31, and the IR CTV in 7/31 of the brachytherapy implants, while dose constraints of OARs bladder and rectum were respected in 28/31 and 14/31 implants. After optimization, the HR CTV and IR CTV dose constraints were respected in all the implants, and the bladder and rectum of cases dose constraints were respected in 25/31 and 17/31 of cases. Point A is a poor surrogate of target dose. Significant differences between point doses and dose volume histogram parameters indicate the need for inverse planning in image-guided brachytherapy of cervical cancer

comparison study of radiation dose received during cone beam computerized tomography and portal imaging techniques

Although widely varied in modality and method, all radiographic guidance techniques have one thing in common; they can give a significant radiation dose to the patient; which may have a late radiation stochastic effect on normal body tissues. To quantify and compare radiation doses to the tumour and the surrounding critical organs resulting from the orthogonal pair portal and megavoltage cone beam computarized tomography [MV CBCT] imaging techniques. The dose to the patient resulting from the orthogonal pair and the MV CBCT imaging techniques, has been calculated based on a 6 MV Oncor linear accelerator equipped with an amorphous silicon flat panel. All calculations were done on Eclipse 3D treatment planning system. 18 patients representing three different treatment sites [head and neck, thorax, and pelvis] were analysed. Data from 6 patients for each treatment site were used to calculate the mean doses. Calculations were done for: The integral dose, maximum dose to the patient, dose at the isocenter, and mean dose to the tumour and each critical organ. The absolute dose measured as integral dose, maximum dose to the patient, dose at the isocenter, and mean dose to the tumour and each critical organ was higher for MV CBCT as compared to orthogonal pair technique for all treatment sites. For both techniques, the absolute dose was higher for head and neck and thorax as compared to pelvis. The difference of maximum dose to the patient showed greater variation for head and neck, but not for thorax and pelvis. There are relatively high dose regions generated by MV CBCT that occur inside critical organs as well treatment area and tend to be larger than those generated by the orthogonal pair technique