4 results
Deep inspirational breath hold to reduce cardiac dose in left-sided breast radiotherapy
- Camarie Welgemoed, Jonathan Rogers, Patti McNaught, Susan Cleator, Pippa Riddle, Dorothy Gujral
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- Journal:
- Journal of Radiotherapy in Practice / Volume 16 / Issue 3 / September 2017
- Published online by Cambridge University Press:
- 22 June 2017, pp. 251-257
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Background
During left-sided breast radiotherapy, the heart is often exposed to radiation dose. Shielding can be utilised to reduce heart exposure, but compromises the dose delivered to the breast tissue and, in a proportion of patients, to the tumour bed. Deep inspiration breath hold (DIBH) can be used as a technique to move the heart away from the treatment area and thus reduce heart dose. This study examines the efficacy of the Elekta Active Breathing Coordinator (ABC), a DIBH method, in reducing heart dose.
Materials and methodsIn total, 12 patients receiving radiotherapy to the left breast were planned for treatment with both a free-breathing (FB) and an ABC scan. The dose volume histogram data for the plans was analysed with respect to heart V13, V5 Gy, mean heart dose and ipsilateral lung V18 Gy. Tumour bed D98%, threshold lung volume in breath hold (BH) and the maximum BH time for each patient was also measured. Patients then received their radiotherapy treatment using the ABC plan and the systematic error in the craniocaudal, lateral and vertical axes was assessed using orthogonal imaging.
ResultsThe median heart V13 Gy for FB and DIBH patients was 3% (range, 0·85–11·28) and 0% (range, 0–1·56), respectively, with a mean heart dose of 2·62 Gy (range, 1·21–4·93) in FB and 1·51 Gy (range, 1·17–2·22) in ABC. The median lung V18 Gy was 8·7% (3·08–14·87) in FB plans and 9% (4·88–12·82) in ABC plans. The mean systematic set-up errors in all three planes were within the departmental set-up tolerance of 5 mm for both techniques. Median FB tumour bed D98% was 97·4% (92·8–99·5) and 97·5% (97·3–98·5) for ABC.
ConclusionABC represents a good method of reducing radiation dose to the heart while not compromising on dose to the tumour bed, and it has a clear advantage over FB radiotherapy in reducing the risk of cardiac toxicity. It is tolerated well by patients and does not produce any difficulties in patient positioning.
Tumour types
- Omer Aziz, Sanjay Purkayastha, Paraskevas Paraskeva
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- Book:
- Hospital Surgery
- Published online:
- 06 July 2010
- Print publication:
- 16 February 2009, pp 571-574
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Summary
Tumours can be classified as benign or malignant. Benign tumours are slow growing, retain normal cell morphology and do not invade tissue or metastasize. They tend not to cause damage to neighbouring structures unless compressive in nature, secondary to being large, or in a critical site e.g. brain, spinal cord. The cardinal characteristics of malignant tumours are their ability to invade and metastasize.
If a malignant tumour remains localized, surgery is the mainstay of curative treatment. Radiotherapy and chemotherapy can be added to reduce the risk of recurrence. If a tumour has metastasized, treatment typically consists of chemotherapy and radiotherapy and, except in the case of highly treatment-sensitive cancers such as testicular and lymphomatous cancers, treatment is palliative.
Tumours can be divided broadly into three sites of origin: epithelial, mesenchymal and haemopoietic. Rarely, tumours can be of mixed origin. Over 80 % of tumours are epithelial in origin. Epithelial malignant tumours are generally named carcinomas and those of mesenchymal origin, sarcomas. The table shows a classification of benign and malignant tumours according to site of origin.
Carcinoma in situ (CIS)
Tumours typically progress from normal cells to premalignant change, to cancer and then on to local invasion and metastatic spread. The premalignant stage is characterized by abnormal (dysplastic) cells that have not transgressed the basement membrane. If left, dysplastic cells may invade and progress to malignancy. Often carcinoma in situ (e.g. of cervix, CIS, or of breast ducts, DCIS) is actively treated to prevent progression to frank malignancy.
Grading
Tumours are graded by the histopathologist. This enables the surgeon and oncologist to stratify the tumour into prognostic groups to aid with tailoring of treatment according to risk of relapse.…
The cancer multidisciplinary team
- Omer Aziz, Sanjay Purkayastha, Paraskevas Paraskeva
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- Book:
- Hospital Surgery
- Published online:
- 06 July 2010
- Print publication:
- 16 February 2009, pp 567-570
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Summary
The origins of the site-specific cancer multidisciplinary team
▪ In 1991 the UK Department of Health consultative document ‘The Health of the Nation’ concluded that cancer accounted for 25% of all deaths, and that death and ill health from cancer should be reduced. ▪ In 1995 the Calman-Hine report took this further, setting out that ‘all patients should have access to a uniformly high quality of care … wherever they may live.’ This was the origin of the term‘postcode lottery’ in relation to cancer care.
▪ In 1997 the NICE Clinical Outcomes Guidelines (COG) for colorectal cancer suggested that there were ‘significant variations both in process and outcomes of colorectal cancer care across the country’ recommending that treatment of cancers should be carried out by ‘a coordinated team with particular interest and expertise in this field‘.
▪ In 2000, the NHS Cancer Plan was published, stating that ‘every patient diagnosed with cancer will benefit from pre-planned care’ and that this care should be ‘delivered by specialist teams in line with evidence on best practice’.
The cancer multidisciplinary team aims to bring together cancer diagnosticians and those involved in cancer treatment and patient support to discuss the diagnostics and all aspects of care of each cancer patient.
Specific responsibilities of the multidisciplinary team (MDT) are to:
▪ Agree appropriate membership and ensure attendance.
▪ Develop systems that collect and present all the relevant information needed for decision making.
▪ Ensure that the care of every cancer patient is discussed at MDT meetings.
▪ Record the decisions that are made.
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Principles of chemotherapy
- Omer Aziz, Sanjay Purkayastha, Paraskevas Paraskeva
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- Book:
- Hospital Surgery
- Published online:
- 06 July 2010
- Print publication:
- 16 February 2009, pp 575-579
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Summary
Chemotherapy is any pharmacological agent given with the intention of eradicating malignant cells, and can be given intravenously, orally and topically. It is the mainstay of treatment of germ cell tumours, lymphomas and leukaemias. It is also used with curative intent as an adjunct to surgery or radiotherapy (RTX) in many tumour types and with palliative intent in metastatic disease.
Systemic chemotherapy: definitions
Neoadjuvant: the use of chemotherapy prior to surgery or RTX to downstage tumour.
Adjuvant: the use of chemotherapy after surgery to eradicate micrometastases and improve overall survival.
Palliative: the use of chemotherapy to palliate symptoms and prolong the life of patients with metastatic disease.
Cytotoxic chemotherapy
Cytotoxic chemotherapy is relatively non-selective. It is not targeted to the tumour and damages normal cells as well as cancer cells. However, malignant cells are more sensitive to its effect because they do not have the same capacity for repair. Cytotoxic drugs predominately damage proliferating cells; malignant tumours are often rapidly growing and therefore susceptible to damage from cytotoxics. Rapidly proliferating normal tissues such as bone marrow and mucous membranes are also often affected, accounting for (some of) the common side-effects of myelosuppression and mucositis.
Cytotoxic chemotherapy drugs have a narrow therapeutic index. This means that the difference between maximum tolerated dose (MTD) and minimum effective dose (MED) tends to be small. Therefore great care is required when prescribing these drugs and patients need to be monitored carefully throughout treatment.
Mechanism of action of cytotoxics
Cytotoxics act at various stages of the cell cycle; different drugs work at different stages.