Biomedical subjects

Syed A Sohaib

Publications and source records attributed to Syed A Sohaib.

3 recordsLinked to original sources

PubMed2006

Evaluating the relationship between erectile dysfunction and dose received by the penile bulb: using data from a randomised controlled trial of conformal radiotherapy in prostate cancer (MRC RT01, ISRCTN47772397).

AIM: To evaluate the relationship between erectile function and the radiation dose to the penile bulb and other proximal penile structures in men receiving conformal radiotherapy (CFRT) for prostate cancer (PCa). METHODS: The Medical Research Council (MRC) RT01 trial randomised 843 men who had localised PCa to receive either 64 or 74 Gy after 3 - 6 months neoadjuvant hormonal treatment. Fifty-one men were selected who were potent prior to hormonal treatment, having completed both pre-hormone and 2-year post-CFRT Quality of Life assessments, and on whom dose volume data were available for analysis. The men were divided into three groups according to 2-year follow-up: potent, reduced potency, and impotent. The bulb of the penis together with the crura, were outlined on restored treatment plans. Dose - volume histograms were generated and compared between the three groups. An ordered logistic regression model was used to calculate the odds ratio of a range of dose - volume parameters to the penile bulb and effect on erectile dysfunction. The dose to the penile bulb was correlated to the dose received by the crura. RESULTS: Of the 51 patients, 12 remained potent, 22 had reduced potency, and 17 were impotent at 2 years. No differences were seen in mean dose to the penile bulb by allocated treatment (t test = 1.61, p = 0.11). The mean doses to the penile bulb received by the potent, reduced potency, and impotent groups were 45.5 Gy (SD 17.1), 48 Gy (SD 16.1), and 59.2 Gy (SD 13.8), respectively. There was a strong correlation between the mean dose received by the penile bulb and dose to the crura (r = 0.82, p < 0.0001). 83.3% of impotent patients received a D90 > or = 50 Gy to the penile bulb compared with 29.4% of patients who maintained potency at 2 years (p = 0.006). CONCLUSION: There is evidence from this study to suggest a dose volume effect on the penile bulb and erectile dysfunction. A D90 > or = 50 Gy is associated with a significant risk of erectile dysfunction and this should form a basis for selecting dose constraints in future dose escalation studies.

Adenocarcinoma↗

PubMed2005

Diagnostic performance of nanoparticle-enhanced magnetic resonance imaging in the diagnosis of lymph node metastases in patients with endometrial and cervical cancer.

PURPOSE: Lymph node metastases affect management and prognosis of patients with gynecologic malignancies. Preoperative nodal assessment with computed tomography or magnetic resonance imaging (MRI) is inaccurate. A new lymph node-specific contrast agent, ferumoxtran-10, composed of ultrasmall particles of iron oxide (USPIO), may enhance the detection of lymph node metastases independent of node size. Our aim was to compare the diagnostic performance of MRI with USPIO against standard size criteria. METHODS: Forty-four patients with endometrial (n = 15) or cervical (n = 29) cancer were included. MRI was performed before and after administration of USPIO. Two independent observers viewed the MR images before lymph node sampling. Lymph node metastases were predicted using size criteria and USPIO criteria. Lymph node sampling was performed in all patients. RESULTS: Lymph node sampling provided 768 pelvic or para-aortic nodes for pathology, of which 335 were correlated on MRI; 17 malignant nodes were found in 11 of 44 patients (25%). On a node-by-node basis, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) by size criteria were 29%*, 99%, 56%, and 96%, and by USPIO criteria (reader 1/reader 2) were 93%/82%* (*P = .008/.004), 97%/97%, 61%/59%, and 100%/99%, respectively (where [*] indicates the statistical difference of P = x/x between the two results marked by the asterisk). On a patient-by-patient basis, sensitivity, specificity, PPV, and NPV by size criteria were 27%*, 94%, 60%, and 79%, and by USPIO criteria (reader 1/reader 2) were 100%/91%* (*P = .031/.06), 94%/87%, 82%/71%, and 100%/96%, respectively. The kappa statistic was 0.93. CONCLUSION: Lymph node characterization with USPIO increases the sensitivity of MRI in the prediction of lymph node metastases, with no loss of specificity. This may greatly improve preoperative treatment planning.

Adult↗

PubMed2002

The anatomy of the perineal membrane: its relationship to injury in childbirth and episiotomy.

BACKGROUND: Episiotomy during childbirth, intended to protect the anal sphincter, may fail to do so. Furthermore damage to the anal sphincter complex may occur without complete perineal tear. We hypothesise that these particular injuries may occur due to posterior displacement of the anus leading to distraction of the anal sphincter complex from an anterior attachment to the perineal membrane. However, the anatomical basis for this has not been well defined. OBJECTIVE: To investigate the relationship between the anal sphincter and the perineal membrane. MATERIALS AND METHODS: High-resolution MRI scans of a female cadaver perineum were performed. The imaging findings were correlated with the anatomical structure identified on dissection and histological examination. RESULTS: The perineal membrane was easily identified on MR imaging. Fibres from the perineal membrane could be seen to attach to the anal sphincter complex at the apex of the perineal body This was confirmed on histological examination and was a deeper layer than that of the decussation of the superficial transverse perineal muscle with the superficial part of the external anal sphincter. CONCLUSION: The upper ano-rectal canal and apex of the perineal body have demonstrable attachment to the free margin of the perineal membrane postero-lateral to the lower vagina. This attachment would resist posterior displacement of the anal canal.

Aged↗