It is to be hoped that if our obstetric colleagues follow these guidelines the use of pelvimetry will be significantly reduced but until the technique truly is obsolete the ALARA principle should be adhered to. St. George’s Hospital London, UK
E. .I. ADAM
TESTICULAR PELVIC CT?
SIR - We wish to report follow-up data to a paper published in Clinical Radiology in February 1997 [l], which clarifies and reinforces the message of the original paper that (contrary to the impression given by RCR guidance on investigation of common malignancies ) not all germ cell testicular tumour (GCTT) patients require surveillance pelvic CT examinations. Accepted risk factors for pelvic nodal involvement in GCTT are maldescent, scrotal surgery (including orchidopexy) prior to orchidectomy for GCTT, invasion of the tunica vaginalis by the primary tumour and bulky abdominal nodal metastases (>5 cm maximum short axis diameter) . The available evidence indicates that bulky abdominal disease as a risk factor for pelvic nodal metastasis should be regarded as >2 cm maximum short axis diameter [l]. Previous retroperitoneal lymphadenectomy (RPLN) should also be regarded as a risk factor. All CT examinations (staging and surveillance) of the chest, abdomen and pelvis in patients with GCTT over an 1&month-period were reviewed (193 examinations on 98 patients). This period was chosen because it was after the original reported 3-year study period but before implementation of a policy of stopping routine surveillance pelvic CT. Inclusion criteria and methods were identical to the original study [l]. The two data sets were combined (giving 619 examinations on 206 patients) and re-analysed. Eighty five of the 206 patients were identified as possessing a risk factor for pelvic nodal metastasis (see Table 1). 192 surveillance pelvic CT examinations were performed in the 121 patients with no risk factors for pelvic nodal metastasis. Pelvic lymph node enlargement was demonstrated at some stage in 21 patients (10.2%), who all possessed risk factor(s) for it. Isolated pelvic lymph node enlargement was uncommon, being demonstrated in only 2/206 patients. The presence of pelvic lymph node enlargement is significantly associated with possession of a risk factor, P
1 - Risk
Current/previous abdominal lymph Current/previous abdominal lymph Maldescermscrotal surgery Tunica vaginalis invasion RPLN Two of the above risk factors Three of the above risk factors
References 1 White PM, Howard GCW, Best JJK, Wright AR. The role of computed tomographic examination of the pelvis in the management of testicular germ cell tumours. Clin Radio1 1997;52:124-129. 2 Royal College of Radiologists. Testicular cancer. In: The Use of Computed Tomography in the Initial Investigation of Common Malignancies. London: RCR 1995;9:25. 3 Mason MD, Featherstone T, Olliff J, Horwich A. Inguinal and iliac lymph node involvement in germ cell tumours of the testis: implications for radiological investigation and for therapy. Clin Oncol 1991;3: 147150.
LONG-TERM VENA CAVA
- We read with interest the article by Harries et al. [l] regarding longterm follow-up of the Antheor inferior vena cava (IVC) filter, which described structural failure in three cases. We have previously reported a case of early structural failure of an Antheor IVC filter which occurred within 20 days of uncomplicated insertion . This complication was immediately reported to the filter manufacturers and the Medical Devices Agency. Initially only a single strut was shown to be fractured. A further strut fracture was noted 4 months later, although the filter remains in a satisfactory position with no evidence of migration or embolization. To date there have been no clinical sequelae during the 33 months since the filter was inserted. Although the long-term significance of strut fracture remains unclear, we concur with Harries et al. [l] that continued follow-up should be undertaken in patients with An&or IVC filters. This will allow complications to be recognized, reported and managed appropriately. SIR
L. J. KING .I. E. DACIE
Department of Diagnostic Imaging St Bartholomew’s Hospital London. UK
References 1 Harries SR, Wells IP, Roobottom CA Long-term follow-up of the Antheor inferior vena cava filter. Clini Radio1 1998;53:350-352. 2 King LJ, Dacie JE. Case report: early structural failure of an Antheor inferior vena caval filter. Clini Radio1 1997;52:632-633.
*Radiology Department, St Mary’s Hospital, London, UK of Clinical Neurosciences, Western General Hospital, Edinburgh, UK
2-5 cm (max. short axis diameter) >5 cm (max. short axis diameter)
18 15 18 6 1 25 2,
Number with pelvic lymph node enlargement 4 10 1 0 0 6 0