Medical practice is constantly changing. The rate of change is accelerating, and physicians can be forgiven if they often find it dizzying. How can physicians learn about new information and innovations, and decide how (if at all) they should modify their practice? Possible sources include summaries from the medical literature (review articles, practice guidelines, consensus statements, editorials, and summary articles in "throwaway" journals); consultation with colleagues who have special expertise; lectures; seminars; advertisements in medical journals; conversations with representatives from pharmaceutical companies; and original articles in journals and journal supplements. Each of these sources of information might be valuable, though each is subject to its own particular biases. 1,2 Problems arise when, as is often the case, these sources of information provide different suggestions about patient care. See also p 2093. Without a way of critically appraising the information they receive, clinicians are relatively helpless in deciding what new information

https://hopkinsmedicine.org/gim/_pdf/jama/17-screening.pdf

Users' Guides to the Medical Literature

This document is the report of a task group of the AAPM and has been prepared primarily to advise medical physicists involved in the external-beam radiation therapy of patients with thoracic, abdominal, and pelvic tumors affected by respiratory motion. This report describes the magnitude of respiratory motion, discusses radiotherapy specific problems caused by respiratory motion, explains techniques that explicitly manage respiratory motion during radiotherapy and gives recommendations in the application of these techniques for patient care, including quality assurance (QA) guidelines for these devices and their use with conformal and intensity modulated radiotherapy. The technologies covered by this report are motion-encompassing methods, respiratory gated techniques, breath-hold techniques, forced shallow-breathing methods, and respiration-synchronized techniques. The main outcome of this report is a clinical process guide for managing respiratory motion. Included in this guide is the recommendation that tumor motion should be measured (when possible) for each patient for whom respiratory motion is a concern. If target motion is greater than 5 mm, a method of respiratory motion management is available, and if the patient can tolerate the procedure, respiratory motion management technology is appropriate. Respiratory motion management is also appropriate when the procedure will increase normal tissue sparing. Respiratory motion management involves further resources, education and the development of and adherence to QA procedures.

/pdf/the-management-of-respiratory-motion-in-radiation-oncology-3m6tr6pexi.pdf

The management of respiratory motion in radiation oncology report of AAPM Task Group 76.

Screening with mammography uses X-ray imaging to find breast cancer before a lump can be felt. The goal is to treat cancer earlier, when a cure is more likely. The review includes seven trials that involved 600,000 women in the age range 39 to 74 years who were randomly assigned to receive screening mammograms or not. The studies which provided the most reliable information showed that screening did not reduce breast cancer mortality. Studies that were potentially more biased (less carefully done) found that screening reduced breast cancer mortality. However, screening will result in some women getting a cancer diagnosis even though their cancer would not have led to death or sickness. Currently, it is not possible to tell which women these are, and they are therefore likely to have breasts or lumps removed and to receive radiotherapy unnecessarily. If we assume that screening reduces breast cancer mortality by 15% after 13 years of follow-up and that overdiagnosis and overtreatment is at 30%, it means that for every 2000 women invited for screening throughout 10 years, one will avoid dying of breast cancer and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress including anxiety and uncertainty for years because of false positive findings.
Women invited to screening should be fully informed of both the benefits and harms. To help ensure that the requirements for informed choice for women contemplating whether or not to attend a screening programme can be met, we have written an evidence-based leaflet for lay people that is available in several languages on www.cochrane.dk. Because of substantial advances in treatment and greater breast cancer awareness since the trials were carried out, it is likely that the absolute effect of screening today is smaller than in the trials. Recent observational studies show more overdiagnosis than in the trials and very little or no reduction in the incidence of advanced cancers with screening.

/pdf/screening-for-breast-cancer-with-mammography-36k7l5kzia.pdf

Screening for breast cancer with mammography.

PURPOSE: To (a) determine the performance of screening mammography, ultrasonography (US), and physical examination (PE); (b) analyze the influence of age, hormonal status, and breast density; (c) compare the size and stage of tumors detected with each modality; and (d) determine which modality or combination of modalities optimize cancer detection. MATERIALS AND METHODS: A total of 11,130 asymptomatic women underwent 27,825 screening sessions, (mammography and subsequent PE). Women with dense breasts subsequently underwent screening US. Abnormalities were deemed positive if biopsy findings revealed malignancy and negative if findings from biopsy or all screening examinations were negative. RESULTS: In 221 women, 246 cancers were found. Sensitivity, specificity, negative and positive predictive values, and accuracy of mammography were 77.6%, 98.8%, 99.8%, 35.8%, and 98.6%, respectively; those of PE, 27.6%, 99.4%, 99.4%, 28.9%, and 98.8%, respectively; and those of US, 75.3%, 96.8%, 99.7%, 20.5%, and 96.6%,...

Comparison of the Performance of Screening Mammography, Physical Examination, and Breast US and Evaluation of Factors that Influence Them: An Analysis of 27,825 Patient Evaluations

https://www.pure.ed.ac.uk/ws/files/8378925/The_benefits_and_harms_of_breast_cancer_screening.pdf

The benefits and harms of breast cancer screening: an independent review

STUDY OBJECTIVE--To determine whether mortality from breast cancer could be reduced by repeated mammographic screening. DESIGN--Birth year cohorts of city population separately randomised into study and control groups. SETTING--Screening clinic outside main hospital. PATIENTS--Women aged over 45; 21,088 invited for screening and 21,195 in control group. INTERVENTIONS--Women in the study group were invited to attend for mammographic screening at intervals of 18-24 months. Five rounds of screening were completed. Breast cancer was treated according to stage at diagnosis. END POINT--Mortality from breast cancer. MEASUREMENTS AND MAIN RESULTS--All women were followed up and classed at end point as alive without breast cancer, alive with breast cancer, dead from breast cancer, or dead from other causes. Cause of death was taken from national mortality registry and for patients with breast cancer was validated independently. Mean follow up was 8.8 years. Altogether 588 cases of breast cancer were diagnosed in the study group and 447 in the control group; 99 v 94 women died of all causes and 63 v 66 women died of breast cancer (no significant difference; relative risk 0.96 (95% confidence interval 0.68 to 1.35)). In the study group 29% more women aged less than 55 died of breast cancer (28 v 22; relative risk 1.29 (0.74 to 2.25)). More women in the study group died from breast cancer in the first seven years; after that the trend reversed, especially in women aged greater than or equal to 55 at entry. Overall, women in the study group aged greater than or equal to 55 had a 20% reduction in mortality from breast cancer (35 v 44; relative risk 0.79 (0.51 to 1.24)). OTHER FINDINGS--In the study group 100 (17%) cancers appeared in intervals between screenings and 107 (18%) in non-attenders; 51 of these women died from breast cancer. Cancers classed as stages II-IV comprised 33% (190/579) of cancers in the study group and 52% (231/443) in the control group. CONCLUSIONS--Invitation to mammographic screening may lead to reduced mortality from breast cancer, at least in women aged 55 or over.

https://www.bmj.com/content/bmj/297/6654/943.full.pdf

Mammographic screening and mortality from breast cancer: the Malmö mammographic screening trial.

What margins should be added to the clinical target volume in radiotherapy treatment planning for lung cancer

The effect of adjuvant combination chemotherapy when given to non-laparotomized patients in remission after radiotherapy in stage I or II non-Hodgkin's lymphoma was studied in a prospective randomized multicenter study. Locally extended field radiotherapy was given to a target absorbed dose of 40 Gy in 20 fractions. Fifty-five patients who were in complete remission 6 weeks after conclusion of radiotherapy were randomized to either no further therapy or to 9 cycles of CVP (cyclophosphamide + vincristine + prednisolone). The relapse-free survival at 30 months was 41% for patients without and 86% for patients with adjuvant chemotherapy (p = 0.02). The survival was the same for both treatment arms, being 90% at 30 months. Fifteen patients have relapsed, 14 of them with extensions and 1 with a recurrence within the radiation target volume. Analysis of subgroups showed that adjuvant chemotherapy in the present series significantly prolonged the relapse-free survival in diffuse histiocytic lymphoma.

CVP-remission-maintenance in stage I or II non-Hodgkin's lymphomas: preliminary results of a randomized study.

Prescribing, Recording, And Reporting Photon Beam Therapy Presentation Of The ICRU Report # 50

The prognosis in medulloblastoma has often been reported to be gloomy, and five-year survival rates of approximately 25% are often reported. In recent years, however, some centers have published results that indicate a possible cure rate of 60% or even more. During the years 1946 to 1975, 50 children received radiotherapy for medulloblastoma at the University Hospital, Lund, Sweden. During this period the target volume had been defined in three different ways, whereas the target-absorbed doses had not differed. When only the demonstrated tumor was treated, the ten-year survival rate was 5%. If the spinal subdural space also was included, it rose to 25%, and when the whole subdural space was treated in addition to the demonstrated tumor, the projected ten-year survival rate was 53%. It is apparent that the target volume in the radiotherapy of medulloblastoma should include not only the demonstrated tumor but also the whole subdural space from the tip of the frontal lobes down to and including the second sacral segment. The size of the target-absorbed dose to be aimed at is not settled, but should consider not only the cure rate but also the performance status of the survivors. It seems from the present seriesmore » that an absorbed dose of 45 Gy in not more than 30 fractions over six weeks to the demonstrated tumor and 30 Gy in 20 fractions over four weeks to the subdural space resulted in a fair frequency of tumor healing and minimal side effects. The delivery of this complicated treatment demands a high degree of precision in the technique. In this material the performance status of the children was not affected by the radiation treatment.« less

T. Landberg

Papers

Mammographic screening and mortality from breast cancer: the Malmö mammographic screening trial.

What margins should be added to the clinical target volume in radiotherapy treatment planning for lung cancer

CVP-remission-maintenance in stage I or II non-Hodgkin's lymphomas: preliminary results of a randomized study.

Prescribing, Recording, And Reporting Photon Beam Therapy Presentation Of The ICRU Report # 50

Improvements in the radiotherapy of medulloblastoma, 1946-1975.