Correspondence
1991, The British Journal of Radiology, 64, 72-14
Correspondence (The Editors do not hold themselves responsible for opinions expressed by correspondents)
Bilateral pneumothorax as a presenting feature of metastatic angiosarcoma of the scalp THE EDITOR—SIR,
Lawton et al (1990) observe that metastatic angiosarcoma is a rare condition and is associated with extremely poor survival following the development of lung complications. They also state that, although radical doses of radiotherapy (44-60 Gy over 4-6 weeks, respectively, 4 fractions per week) have been followed by long term control of local disease, this may not necessarily correlate with improved survival. A further case, identified by retrospective review of patients' records of the Skin Unit of the Peter MacCallum Cancer Institute (PMCI) in Melbourne, is described here to report the response to hypofractionated treatment. An 81-year-old woman presented to her GP with a 4-month history of a "blood blister" on the right forehead, initially 2 cm in diameter, which had rapidly increased in size to 8 x 5 x 3 cm. Following surgical referral, the lesion was completely excised and the defect grafted. One month post-operatively, however, an extensive area of induration and pigmentation was noted arising from the inferior aspect of the surgical site. A diagnosis of recurrent disease was confirmed and the patient referred to the PMCI for radiotherapy. Treatment was prescribed with superficial radiotherapy using a 70 x 70 mm field to cover the clinically determined extent of disease and giving 30 Gy skin dose in 3 fractions at I/week. Treatment was well tolerated and a complete response was documented on clinical examination 2 months after completion of superficial radiotherapy. However, a further 4 months later, the patient complained of haemoptysis, and a chest radiograph was reported as showing multiple opacities in both lungs consistent with metastatic disease. Megavoltage irradiation was given to the mediastinum and adjacent lungfields using anterior and posterior parallel opposed fields, giving 12 Gy maximum permissible dose in 3 fractions in 1 week. The haemoptysis settled after the first fraction and a repeat chest radiograph on subsequent follow-up showed the persistence of only one nodule in the left lower bone, outside the treatment field. The patient remained asymptomatic for the following 9 months, when she again complained of haemoptysis. There was no clinical evidence of active disease at the primary site. Chest radiography showed progressive disease with widespread nodules, and despite further palliative megavoltage therapy, the patient's condition deteriorated rapidly and she died 2 months later. Post-mortem examination was not performed. Sarcomas are generally regarded as relatively unresponsive to radiation and it has been proposed that, if this is because of the presence of a large shoulder on the cell survival curve, then using fewer large fractions (hypofractionation) might be expected to improve response. However, large dose fractions increase late normal tissue damage which is of great importance in radical treatment. This was noted in 23 out of 32 evaluable patients in the study by Ashby et al (1986), who reported no apparent improvement in therapeutic gain for large weekly fractions. In the case presented here, owing to the aggressive nature of the disease, with short presenting history and time of first recurrence, the initial radiotherapy was given only with
72
palliative intent. A complete remission was noted, however, and although metastases developed, there was no evidence of further active disease at the primary site. Similarly, after a short course of megavoltage therapy to the chest, at least a partial response was seen initially and palliation of symptoms was successful, although local control of disease was not gained. This report illustrates that short courses of large dose fractions may be sufficient to achieve treatment objectives in the management of locally advanced and metastatic angiosarcoma. Yours, etc. BRUCE SIZER
Essex County Hospital, Lexden Road, Colchester, Essex, UK {Received July 1990) References ASHBY,
M.
A.,
AGO, C.
T.
&
HARMER,
C. L.,
1986.
Hypofractionated radiotherapy for sarcomas. International Journal of Radiation Oncology, Biology, Physics, 12, 13-17. LAWTON, P. A., KNOWLES, S., KARP, S. J., SUVANA, S. K. &
SPITTLE, M. F., 1990. Bilateral pneumothorax as a presenting feature of metastatic angiosarcoma of the scalp. British Journal of Radiology, 63, 132-134.
Retroperitoneal haematoma and pelvic haematoma following orchidectomy THE EDITOR—SIR,
We read with interest the papers by Page et al (1990) and Russell et al (1990) on the importance of differentiating retroperitoneal haematoma following transinguinal
Figure 1. Computed tomographic scan at the level of the lower pole of the right kidney demonstrating thickening of the Gerota's and lateroconal fasciae. The British Journal of Radiology, January 1991
Correspondence orchidectomy from metastatic lymph node involvement. We have recently seen a 24-year-old man who underwent a right inguinal orchidectomy for testicular swelling of 3 months duration. Histological examination of the resected testis showed malignant teratoma undifferentiated (MTU), with no evidence of vascular invasion and absence of yolk sac elements. Tumour markers were negative pre-operatively and have remained so. A staging computed tomogram (CT) performed 7 days post-operatively demonstrated an 8 cm high attenuation mass in the right side of the pelvis extending superiorly to the lower pole of the right kidney. In addition there was marked thickening of the lateroconal and Gerota's fasciae, increased attenuation of the perirenal fat and loss of the normal fat planes around the inferior vena cava (Fig. 1). This finding indicated the inflammatory nature of the lesion and prompted the correct diagnosis. The haemoglobin was then noted to have fallen to 10.3 g/dl. Four weeks post-orchidectomy the patient is well. No antitumour therapy is planned. We find it surprising that in the six reported cases there was no mention of a similar appearance. The presence of inflammation in conjunction with the characteristic CT appearances of retroperitoneal haematoma (Jeffery, 1983) should enable the correct diagnosis to be made. Yours, etc. C. KENNEDY *S. HARLAND *G. WATSON *C. PARKER
Department of Imaging, The Middlesex Hospital, Mortimer Street, London WIN 8AA and •The London Institute of Urology, London WC2H 8JE (Received July 1990) References PAGE, J.
E.,
PRENDERGAST, C.
M.
&
KING, D. M.,
1990.
Retroperitoneal haematoma following orchidectomy: implications for staging computed tomography. British Journal of Radiology, 63, 490-492. RUSSELL, S. A., JOHNSON, R. J. & RUSSELL, J. M., 1990. Pelvic
haematoma following orchidectomy: a pitfall in the staging of non-seminomatous germ cell tumour. British Journal of Radiology, 63, 492^94. JEFFERY, R. B., 1983. Computed tomography of the lymphovascular structures and retroperitoneal soft tissues. In Computed Tomography of the Body. Ed. by A. A. Moss, G. Gamsu and H. K. Genant (Saunders, Philadelphia), pp. 936-937; 946-947.
The physical dimensions of the compressed breast THE EDITOR—SIR,
The success of the National Breast Screening Program relies on accurate dose measurements, essential for any risk-benefit analysis and radiation protection considerations (Forrest, 1986). This need to measure absorbed doses within and around the irradiated breast necessitates the use of carefully selected materials from which phantoms and radiation detectors can be constructed. In addition, the relevancy of the geometry and
Vol. 64, No. 757
Table I. Results of the Compressed Breast Size Study Age (years) Mean 48 .5 Standard deviation 9 .1 Maximum value 82 Minimum value 31
Thickness (cm)
Width (cm)
Breadth (cm)
5.2 1.1 8.6 2.5
18 2.4 25 12
8.1 2.1 17.4 1.4
physical dimensions of anthropomorphic phantoms is paramount. Breast phantoms for image quality and dosimetry should be pertinent to the breast which has been compressed for examination, similarly tissue substitutes used in the phantom must have either known elemental composition and mass densities or known radiation absorption and scattering properties for the relevant type and energy of radiation used in mammography (ICRU, 1989). To this end a study has been carried out to find an average compressed breast size. The study was not meant to increase the patient examination time and certainly not prolong the time the breast was under compression. Mammographers filled in a form with data on thickness, width and breadth of each breast, exposure factors and the age of the individual. The thickness of the compressed breast was read off a scale on the mammography unit. The other measurements of width of breast and distance from the nipple to the chest wall were recorded from the mammographs. These dimensions have been called thickness, width and breadth. These terms are clarified in Fig. 1. The results of this study are from 216 different compressed breasts and are shown in Table I. The compressed breast size study has given an average thickness under compression of 5.2+1.1 cm with a range in thicknesses of 2.5 cm to 8.6 cm. Several authors have calculated optimum X-ray energies for mammography using, as a criterion, the maximum signal-tonoise ratio obtainable per unit absorbed dose to the breast (Beaman & Lillicrap, 1982). The predicted optimum X-ray energy increases with breast thickness. However, increasing the generator voltage has little effect on the spectrum from a molybdenum target (Marshall et al, 1975). This average thickness of 5.2 cm suggests improved image quality with optimum spectra from a filtered tungsten target as opposed to a molybdenum target molybdenum filter combination (Beaman & Lillicrap, 1982). However, the NHS Procurement Directorate has already stipulated that the target material of mammography units in Breast Screening and Assessment Centres should be molybdenum (DHSS, 1987). The dimensions of the study are also up to 3 cm thicker than some of the available breast phantoms on the market today. A factor which affects the measured compressed breast size is the mammographic technique itself. Breast Screening Centres may not yet be uniform in their application of compression, and it is important to record widths and breadths from the mammographs along with thicknesses. When width and breadth measurements from one centre are comparable to another centre yet the thicknesses are smaller, it may be inferred that the latter centre is applying firmer compression than the former. If a centre presents with all dimensions being larger than the norm then that centre may well be examining a sample from a population of larger than normal breasts. It is
73
1991, The British Journal of Radiology, 64, 72-14
Correspondence (The Editors do not hold themselves responsible for opinions expressed by correspondents)
Bilateral pneumothorax as a presenting feature of metastatic angiosarcoma of the scalp THE EDITOR—SIR,
Lawton et al (1990) observe that metastatic angiosarcoma is a rare condition and is associated with extremely poor survival following the development of lung complications. They also state that, although radical doses of radiotherapy (44-60 Gy over 4-6 weeks, respectively, 4 fractions per week) have been followed by long term control of local disease, this may not necessarily correlate with improved survival. A further case, identified by retrospective review of patients' records of the Skin Unit of the Peter MacCallum Cancer Institute (PMCI) in Melbourne, is described here to report the response to hypofractionated treatment. An 81-year-old woman presented to her GP with a 4-month history of a "blood blister" on the right forehead, initially 2 cm in diameter, which had rapidly increased in size to 8 x 5 x 3 cm. Following surgical referral, the lesion was completely excised and the defect grafted. One month post-operatively, however, an extensive area of induration and pigmentation was noted arising from the inferior aspect of the surgical site. A diagnosis of recurrent disease was confirmed and the patient referred to the PMCI for radiotherapy. Treatment was prescribed with superficial radiotherapy using a 70 x 70 mm field to cover the clinically determined extent of disease and giving 30 Gy skin dose in 3 fractions at I/week. Treatment was well tolerated and a complete response was documented on clinical examination 2 months after completion of superficial radiotherapy. However, a further 4 months later, the patient complained of haemoptysis, and a chest radiograph was reported as showing multiple opacities in both lungs consistent with metastatic disease. Megavoltage irradiation was given to the mediastinum and adjacent lungfields using anterior and posterior parallel opposed fields, giving 12 Gy maximum permissible dose in 3 fractions in 1 week. The haemoptysis settled after the first fraction and a repeat chest radiograph on subsequent follow-up showed the persistence of only one nodule in the left lower bone, outside the treatment field. The patient remained asymptomatic for the following 9 months, when she again complained of haemoptysis. There was no clinical evidence of active disease at the primary site. Chest radiography showed progressive disease with widespread nodules, and despite further palliative megavoltage therapy, the patient's condition deteriorated rapidly and she died 2 months later. Post-mortem examination was not performed. Sarcomas are generally regarded as relatively unresponsive to radiation and it has been proposed that, if this is because of the presence of a large shoulder on the cell survival curve, then using fewer large fractions (hypofractionation) might be expected to improve response. However, large dose fractions increase late normal tissue damage which is of great importance in radical treatment. This was noted in 23 out of 32 evaluable patients in the study by Ashby et al (1986), who reported no apparent improvement in therapeutic gain for large weekly fractions. In the case presented here, owing to the aggressive nature of the disease, with short presenting history and time of first recurrence, the initial radiotherapy was given only with
72
palliative intent. A complete remission was noted, however, and although metastases developed, there was no evidence of further active disease at the primary site. Similarly, after a short course of megavoltage therapy to the chest, at least a partial response was seen initially and palliation of symptoms was successful, although local control of disease was not gained. This report illustrates that short courses of large dose fractions may be sufficient to achieve treatment objectives in the management of locally advanced and metastatic angiosarcoma. Yours, etc. BRUCE SIZER
Essex County Hospital, Lexden Road, Colchester, Essex, UK {Received July 1990) References ASHBY,
M.
A.,
AGO, C.
T.
&
HARMER,
C. L.,
1986.
Hypofractionated radiotherapy for sarcomas. International Journal of Radiation Oncology, Biology, Physics, 12, 13-17. LAWTON, P. A., KNOWLES, S., KARP, S. J., SUVANA, S. K. &
SPITTLE, M. F., 1990. Bilateral pneumothorax as a presenting feature of metastatic angiosarcoma of the scalp. British Journal of Radiology, 63, 132-134.
Retroperitoneal haematoma and pelvic haematoma following orchidectomy THE EDITOR—SIR,
We read with interest the papers by Page et al (1990) and Russell et al (1990) on the importance of differentiating retroperitoneal haematoma following transinguinal
Figure 1. Computed tomographic scan at the level of the lower pole of the right kidney demonstrating thickening of the Gerota's and lateroconal fasciae. The British Journal of Radiology, January 1991
Correspondence orchidectomy from metastatic lymph node involvement. We have recently seen a 24-year-old man who underwent a right inguinal orchidectomy for testicular swelling of 3 months duration. Histological examination of the resected testis showed malignant teratoma undifferentiated (MTU), with no evidence of vascular invasion and absence of yolk sac elements. Tumour markers were negative pre-operatively and have remained so. A staging computed tomogram (CT) performed 7 days post-operatively demonstrated an 8 cm high attenuation mass in the right side of the pelvis extending superiorly to the lower pole of the right kidney. In addition there was marked thickening of the lateroconal and Gerota's fasciae, increased attenuation of the perirenal fat and loss of the normal fat planes around the inferior vena cava (Fig. 1). This finding indicated the inflammatory nature of the lesion and prompted the correct diagnosis. The haemoglobin was then noted to have fallen to 10.3 g/dl. Four weeks post-orchidectomy the patient is well. No antitumour therapy is planned. We find it surprising that in the six reported cases there was no mention of a similar appearance. The presence of inflammation in conjunction with the characteristic CT appearances of retroperitoneal haematoma (Jeffery, 1983) should enable the correct diagnosis to be made. Yours, etc. C. KENNEDY *S. HARLAND *G. WATSON *C. PARKER
Department of Imaging, The Middlesex Hospital, Mortimer Street, London WIN 8AA and •The London Institute of Urology, London WC2H 8JE (Received July 1990) References PAGE, J.
E.,
PRENDERGAST, C.
M.
&
KING, D. M.,
1990.
Retroperitoneal haematoma following orchidectomy: implications for staging computed tomography. British Journal of Radiology, 63, 490-492. RUSSELL, S. A., JOHNSON, R. J. & RUSSELL, J. M., 1990. Pelvic
haematoma following orchidectomy: a pitfall in the staging of non-seminomatous germ cell tumour. British Journal of Radiology, 63, 492^94. JEFFERY, R. B., 1983. Computed tomography of the lymphovascular structures and retroperitoneal soft tissues. In Computed Tomography of the Body. Ed. by A. A. Moss, G. Gamsu and H. K. Genant (Saunders, Philadelphia), pp. 936-937; 946-947.
The physical dimensions of the compressed breast THE EDITOR—SIR,
The success of the National Breast Screening Program relies on accurate dose measurements, essential for any risk-benefit analysis and radiation protection considerations (Forrest, 1986). This need to measure absorbed doses within and around the irradiated breast necessitates the use of carefully selected materials from which phantoms and radiation detectors can be constructed. In addition, the relevancy of the geometry and
Vol. 64, No. 757
Table I. Results of the Compressed Breast Size Study Age (years) Mean 48 .5 Standard deviation 9 .1 Maximum value 82 Minimum value 31
Thickness (cm)
Width (cm)
Breadth (cm)
5.2 1.1 8.6 2.5
18 2.4 25 12
8.1 2.1 17.4 1.4
physical dimensions of anthropomorphic phantoms is paramount. Breast phantoms for image quality and dosimetry should be pertinent to the breast which has been compressed for examination, similarly tissue substitutes used in the phantom must have either known elemental composition and mass densities or known radiation absorption and scattering properties for the relevant type and energy of radiation used in mammography (ICRU, 1989). To this end a study has been carried out to find an average compressed breast size. The study was not meant to increase the patient examination time and certainly not prolong the time the breast was under compression. Mammographers filled in a form with data on thickness, width and breadth of each breast, exposure factors and the age of the individual. The thickness of the compressed breast was read off a scale on the mammography unit. The other measurements of width of breast and distance from the nipple to the chest wall were recorded from the mammographs. These dimensions have been called thickness, width and breadth. These terms are clarified in Fig. 1. The results of this study are from 216 different compressed breasts and are shown in Table I. The compressed breast size study has given an average thickness under compression of 5.2+1.1 cm with a range in thicknesses of 2.5 cm to 8.6 cm. Several authors have calculated optimum X-ray energies for mammography using, as a criterion, the maximum signal-tonoise ratio obtainable per unit absorbed dose to the breast (Beaman & Lillicrap, 1982). The predicted optimum X-ray energy increases with breast thickness. However, increasing the generator voltage has little effect on the spectrum from a molybdenum target (Marshall et al, 1975). This average thickness of 5.2 cm suggests improved image quality with optimum spectra from a filtered tungsten target as opposed to a molybdenum target molybdenum filter combination (Beaman & Lillicrap, 1982). However, the NHS Procurement Directorate has already stipulated that the target material of mammography units in Breast Screening and Assessment Centres should be molybdenum (DHSS, 1987). The dimensions of the study are also up to 3 cm thicker than some of the available breast phantoms on the market today. A factor which affects the measured compressed breast size is the mammographic technique itself. Breast Screening Centres may not yet be uniform in their application of compression, and it is important to record widths and breadths from the mammographs along with thicknesses. When width and breadth measurements from one centre are comparable to another centre yet the thicknesses are smaller, it may be inferred that the latter centre is applying firmer compression than the former. If a centre presents with all dimensions being larger than the norm then that centre may well be examining a sample from a population of larger than normal breasts. It is
73
