[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

The Central Committee for Quality Control of Mammography Screening (CCQCMS) has established a Subcommittee for Education and Subcommittee for Imaging Unit Evaluation, and has carried out activities to establish quality control of breast cancer screening with the cooperation of six related societies. The Subcommittee for Education has been offering mammography training courses for doctors and technicians since March, 1999. Recently, more than 50 courses in mammogram reading and technical training have been carried out annually throughout Japan under the auspices of the CCQCMS and other societies. Up to March 31, 2008, 12,051 mammogram reading doctors and 12,591 mammography technicians had attended training courses.
The CCQCMS introduced a recertification system in 2007 in order to maintain a high quality of mammography screening. In this paper, we explain the purpose of introducing this recertification system and describe the practical lecture contents for mammogram reading and technical training. We also explain the practical aspects of recertification and how to cater for those who have not applied for recertification during the above period. By introducing the recertification system, we hope that education will be carried out continuously and that a practical system can be established. Hereafter the CCQCMS will actively provide a high-quality breast cancer screening system for the whole of Japan.

View full abstract

Among a total of 158 patients whose breast cancers were detected by precise breast cancer screening examinations carried out at our clinic during a period of two and a half years from January 2004 to about June 2006, 78 had early cancer (T0 or T1).
We retrospectively studied the limit of inspection and palpation, echography and mammography at detection of early breast cancer for these 78 patients. The results obtained were as follows:
1) The breast tumor was not palpable in 40.1% of all early cancers in this series.
2) In patients with T0 cancer, whose tumors were not palpable, tumors of 5mm in size or larger could be detected by a combination of mammography and echography, while those measuring 4mm or less were extremely difficult to detect even by these methods.
3) Ultrasonography is mostly useful for detecting nonpalpable cancer and for women with dense breasts. Since false negative results were obtained in 5 of 32 patients with T0 cancers (15.6%), we think that considerably more studies are required before ultrasonography can be adopted at its current level for routine breast cancer screening.
4) In patients with palpable cancers (T1, T2 or T3), the false negative ratio for mammography and echography was 4.8% and 2.4%, respectively. These cancers would have been missed if we had not performed inspection and palpation. We think that both inspection and palpation are necessary for breast cancer screening.

View full abstract

To ensure a sufficient number of doctors who are qualified to read screening mammograms in Hyogo Prefecture, we have held mammography training courses five times a year since December 2005, and preparatory short courses have been held beforehand three times. The preparatory course comprises a preliminary course and a course prepared for those advancing further. We distributed all applicants of these courses into two groups. The first (I) consisted of applicants taking instruction since the preparatory course, and the second (II), those without the preparatory course. We then estimated the efficacy of instruction of these applicants as the percentage of pass grades or correct answers. About 75 percent of applicants having experience in reading clinical mammograms passed, compared with less than 30 percent of those having no experience. Preliminary instruction effectively boosted the proportion of pass grades by about 20 percent, regardless of clinical experience. The percentages of correct category answers among group I were apparently higher than those in group II for tumor and calcification, and we found a similar result for architectural distortion. However, there was no significant difference between the groups for FAD. Consequently we assumed that preliminary instruction was at least as effective as participation in previous breast cancer treatments for improving skill at reading screen mammograms.

View full abstract

The number of screenees who are recalled because of mammographic demonstration of minute calcific deposits has been increasing. We have been using stereotactic mammotome biopsy (SMB) as a good method for obtaining a definite pathologic diagnosis of such lesions showing minor invasion. Here we introduce our method and present the results.
SMB was performed on 450 screenees who showed minute calcific deposits at mammographic screening during a period of five and a half years from May 2002 through October 2007. The calcification categories were: Category 2, 9.8% (44 women); Category 3, 68.2% (307 women);Category 4, 16% (72 women); and Category 5, 6% (27 women).
We were able to obtain samples of calcific deposits successfully and make definite diagnoses in all cases. The breast cancer detection rates in each category were 0% (no case) in Category 2, 7.8% (24 cases) in Category 3, 22.2% (16 cases) in Category 4, 85.1% (23 cases) in Category 5, and 14% (63 cases) overall.
When performing mammotome biopsies, we carried out several dry runs and stepwise technical maneuvers to make the screenees feel relaxed and to obtain tissue specimens successfully. The examination time and the rate of complications were compared between 223 screenees in the former half of the study period (from May 2002 through October 2005) and 227 screenees in the latter half (from October 2005 through October 2007). The mean examination time in the former period was 38.7 min, and this was significantly shortened to 26.0 min in the latter period. The respective rates of complications in the former and latter periods were: anxiety 4.5% and 1.8%; post-biopsy bleeding 4.0% and 1.3%; and wound infection 0.4% and 0%. Thus fewer complications were observed in the latter period.
In conclusion, we successfully obtained a definite histologic diagnosis in all screenees with minute calcific deposits by means of mammotome biopsy. By carrying out several technical attempts and accumulating experience, we were able to shorten the examination time and decrease the rate of complications.

View full abstract

Quality control is essential for mammography. In the manual of mammography quality control, two important items are described:one is a beam quality (HVL) for evaluating X-ray equipment, and the other is determination of mean mammary gland dose for evaluating the system, which is measured using a dosimeter corrected by low-energy radiation and using a high-purity aluminum sheet. At present, however, many institutions that have mammography equipment appear not to keep a dosimeter or a high-purity aluminum sheet.
We have tried using a glass dosimeter for quality control of mammography (hereafter called simply “glass dosimeter”), which was able to measure HVL and incident exposure in air at one exposure. With the use of this glass dosimeter, we measured HVL, incident exposure in air, and mean mammary gland dose under the usual mammography exposure conditions, and the results were compared with those obtained using an ionization chamber dosimeter. Aspects of cost were also compared, and the usefulness of the glass dosimeter was evaluated from a quality control aspect.
When we used the glass dosimeter, HVL became as thin as 0.01 mm at maximum, the error of incident exposure in air was less than 7% and that of mean mammary gland dose was less than 10%. Estimation of the cost of quality control revealed that use of the glass dosimeter was cheaper than use of the ionization chamber dosimeter.
Thus quality control using of a glass dosimeter is simpler and cheaper than using an ionization chamber dosimeter. It is suggested that institutions possessing no ionization chamber dosimeter may maintain good quality control by periodical use of a glass dosimeter.

View full abstract

A 70-year-old woman visited our hospital in response to a recall because of detection of calcification in the left breast by mammographic screening. Ultrasonography showed convergence of dilated ducts with calcification, and aspiration biopsy cytology indicated a “suspicious lesion”. MRI study to determine the quality and extent of the lesion showed a time intensity curve suspicious for cancer. Breast-preserving surgery was performed, and the pathologic diagnosis was papillotubular carcinoma, consisting largely of non-invasive ductal carcinoma and partly associated with institutional invasion.
This case illustrates that, for a non-tumor-forming breast lesion first noted by mammographic detection of minute calcific deposits, ultrasonography-assisted aspiration biopsy cytology is useful for diagnosis of breast cancer, and that MRI findings are also helpful for supporting a definite diagnosis of cancer in cases where a lesion is suspicious.

View full abstract