Aslam Sohaib

The Royal Marsden NHS Foundation Trust, Londinium, England, United Kingdom

Are you Aslam Sohaib?

Claim your profile

Publications (32)77.47 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The delivery of a simultaneous integrated boost to the intra-prostatic tumour nodule may improve local control. The ability to deliver such treatments with hypofractionated SBRT was attempted using RapidArc (Varian Medical systems, Palo Alto, CA) and Multiplan (Accuray inc, Sunnyvale, CA).Materials and methods: 15 patients with dominant prostate nodules had RapidArc and Multiplan plans created using a 5 mm isotropic margin, except 3 mm posteriorly, aiming to deliver 47.5 Gy in 5 fractions to the boost whilst treating the whole prostate to 36.25 Gy in 5 fractions. An additional RapidArc plan was created using an 8 mm isotropic margin, except 5 mm posteriorly, to account for lack of intrafraction tracking. Both RapidArc and Multiplan can produce clinically acceptable boost plans to a dose of 47.5 Gy in 5 fractions. The mean rectal doses were lower for RapidArc plans (D50 13.2 Gy vs 15.5 Gy) but the number of missed constraints was the same for both planning methods (11/75). When the margin was increased to 8 mm/5 mm for the RapidArc plans to account for intrafraction motion, 37/75 constraints were missed. RapidArc and Multiplan can produce clinically acceptable simultaneous integrated boost plans, but the mean rectal D50 and D20 with RapidArc are lower. If the margins are increased to account for intrafraction motion, the RapidArc plans exceed at least one dose constraint in 13/15 cases. Delivering a simultaneous boost with hypofractionation appears feasible, but requires small margins needing intrafraction motion tracking.
    Radiation Oncology 10/2013; 8(1):228. · 2.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The current pathway for men suspected of having prostate cancer [transrectal biopsy, followed in some cases by magnetic resonance imaging (MRI) for staging] results in over-diagnosis of insignificant tumours, and systematically misses disease in the anterior prostate. Multiparametric MRI has the potential to change this pathway, and if performed before biopsy, might enable the exclusion of significant disease in some men without biopsy, targeted biopsy in others, and improvements in the performance of active surveillance. For the potential benefits to be realized, the setting of standards is vital. This article summarizes the outcome of a meeting of UK radiologists, at which a consensus was achieved on (1) the indications for MRI, (2) the conduct of the scan, (3) a method and template for reporting, and (4) minimum standards for radiologists.
    Clinical Radiology 07/2013; · 1.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE: To describe the experience of laparoscopic staging of apparent early stage adnexal cancers. METHODS: Prospectively collected data on women who had laparoscopic staging for apparent early stage adnexal cancers from May 2008 to September 2012 was reviewed. All women had had a prior surgical procedure at which the diagnosis was made, without comprehensive staging. A systematic MEDLINE search from 1980 to 2012 for publications on laparoscopic staging was performed. RESULTS: Thirty-five women had laparoscopic staging. Median age was 45 years (range 21-73). Median operative time was 210 min (range 90-210). Four intra-operative and one post-operative complication occurred; overall complication rate 5/35 (14%). One vena cava and one transverse colon injury underwent laparotomies for repair. Laparotomy conversion rate 2/35 (6%). Following laparoscopic staging, the cancer was upstaged for eight (23%) women; microscopic omental involvement (four women), pelvic lymph node involvement (two women), para-aortic lymph node involvement (one woman) and contra-lateral ovarian involvement (one woman). After follow up for a median of 18 months (range 3-59) the disease free survival was 94% and overall survival was 100%. Nine studies were identified on laparoscopic staging of adnexal cancer, of which this is the largest single institution series. CONCLUSIONS: This study adds to the evidence that laparoscopic staging is at least as safe as staging by laparotomy with appropriate and similar oncological outcomes, but with the advantages of minimal access surgery. We therefore advocate the use of laparoscopy to achieve surgical staging for women with presumed early stage adnexal cancer.
    European journal of surgical oncology: the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology 05/2013; · 2.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Extended field radiotherapy is a standard of care for low volume stage II testicular seminoma. We hypothesized that neoadjuvant carboplatin might reduce the recurrence risk.Patients and methodsIn a single-arm study, 51 patients were treated between May 1996 and November 2011 with a single cycle of carboplatin followed by radiotherapy. The radiation field was reduced from an extended abdomino-pelvic field to just the para-aortic region, and the radiation dose from 35 Gy to 30 Gy in 39 patients.ResultsAfter a median follow-up of 55 months (range 8-151 months) with 38 (74%) of the patients having been followed for >2 years, there have been no relapses (95% confidence limits of 5-year relapse-free survival of 93%-100%). Toxicity has been low with grade 3 toxicity limited to four patients with grade 3 haematological toxicity (with no clinical sequelae) and one patient with grade 3 nausea (during radiotherapy). No patients experienced grade 4 toxicity.Conclusions The results of this pilot study suggest that a single cycle of neoadjuvant carboplatin before radiotherapy may reduce recurrence risk compared with radiotherapy alone and permit a smaller radiation field, and this approach is proposed for further investigation.
    Annals of Oncology 04/2013; · 7.38 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In November 2011, the Third European Consensus Conference on Diagnosis and Treatment of Germ-Cell Cancer (GCC) was held in Berlin, Germany. This third conference followed similar meetings in 2003 (Essen, Germany) and 2006 (Amsterdam, The Netherlands) [Schmoll H-J, Souchon R, Krege S et al. European consensus on diagnosis and treatment of germ-cell cancer: a report of the European Germ-Cell Cancer Consensus Group (EGCCCG). Ann Oncol 2004; 15: 1377-1399; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part I. Eur Urol 2008; 53: 478-496; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part II. Eur Urol 2008; 53: 497-513]. A panel of 56 of 60 invited GCC experts from all across Europe discussed all aspects on diagnosis and treatment of GCC, with a particular focus on acute and late toxic effects as well as on survivorship issues.The panel consisted of oncologists, urologic surgeons, radiooncologists, pathologists and basic scientists, who are all actively involved in care of GCC patients. Panelists were chosen based on the publication activity in recent years. Before the meeting, panelists were asked to review the literature published since 2006 in 20 major areas concerning all aspects of diagnosis, treatment and follow-up of GCC patients, and to prepare an updated version of the previous recommendations to be discussed at the conference. In addition, ∼50 E-vote questions were drafted and presented at the conference to address the most controversial areas for a poll of expert opinions. Here, we present the main recommendations and controversies of this meeting. The votes of the panelists are added as online supplements.
    Annals of Oncology 11/2012; · 7.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: Intensity modulated radiation therapy (IMRT) is a significant therapeutic advance in prostate cancer, allowing increased tumor dose delivery and increased sparing of normal tissues. IMRT planning uses strict dose constraints to nearby organs to limit toxicity. Bile acid malabsorption (BAM) is a treatable disorder of the terminal ileum (TI) that presents with symptoms similar to radiation therapy toxicity. It has not been described in patients receiving RT for prostate cancer in the contemporary era. We describe new-onset BAM in men after IMRT for prostate cancer. METHODS AND MATERIALS: Diagnosis of new-onset BAM was established after typical symptoms developed, selenium-75 homocholic acid taurine (SeHCAT) scanning showed 7-day retention of <15%, and patients' symptoms unequivocally responded to a bile acid sequestrant. The TI was identified on the original radiation therapy plan, and the radiation dose delivered was calculated and compared with accepted dose-volume constraints. RESULTS: Five of 423 men treated in a prospective series of high-dose prostate and pelvic IMRT were identified with new onset BAM (median age, 65 years old). All reported having normal bowel habits before RT. The volume of TI ranged from 26-141 cc. The radiation dose received by the TI varied between 11.4 Gy and 62.1 Gy (uncorrected). Three of 5 patients had TI treated in excess of 45 Gy (equivalent dose calculated in 2-Gy fractions, using an α/β ratio of 3) with volumes ranging from 1.6 cc-49.0 cc. One patient had mild BAM (SeHCAT retention, 10%-15%), 2 had moderate BAM (SeHCAT retention, 5%-10%), and 2 had severe BAM (SeHCAT retention, <5%). The 3 patients whose TI received ≥45 Gy developed moderate to severe BAM, whereas those whose TI received <45 Gy had only mild to moderate BAM. CONCLUSIONS: Radiation delivered to the TI during IMRT may cause BAM. Identification of the TI from unenhanced RT planning computed tomography scans is difficult and may impede accurate dosimetric evaluation. Thorough toxicity assessment and close liaison between oncologist and gastroenterologist allow timely diagnosis and treatment.
    International journal of radiation oncology, biology, physics 09/2012; · 4.59 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVES: To assess the morphological and enhancement features of histologically proven cystadenofibromas (CAFs) on magnetic resonance imaging (MRI). METHODS: Forty-seven histologically proven CAFs (42 benign, five borderline) were retrospectively reviewed. One benign CAF had a synchronous adenocarcinoma in the same ovary. The morphological, signal and enhancement characteristics on MRI were recorded. RESULTS: The mean long axis diameter of the CAFs was 80 mm. The contralateral ovary was abnormal in 45 % of cases. A solid component was seen in 85 %, which returned low T2-weighted signal in 75 % of CAFs. Septa were seen in 74 % and one CAF was purely cystic. The majority of solid components and septa demonstrated enhancement that was less than the myometrium. Wash-in rates (WIR) of the solid tissue were available for measurement in nine patients with an average WIR of 3.2 l/s. CONCLUSION: This is the largest series describing MRI appearances of histologically proven CAFs. They are typically complex adnexal lesions containing septa, cystic components and solid tissue. The majority of solid components demonstrate low T2 signal and minimal enhancement. Almost half of the cases have an abnormal contralateral ovary. KEY POINTS : • Cystadenofibromas are complex adnexal lesions containing septa, cystic, and solid components. • Some MRI features of cystadenofibromas overlap with those of malignant ovarian lesions. • Almost 50 % of patients with a cystadenofibroma have an abnormal contralateral ovary. • Most contralateral lesions are benign, but we found four borderline tumours.
    European Radiology 07/2012; · 4.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Multiparametric magnetic resonance imaging (mpMRI) is increasingly being used earlier in the prostate cancer diagnostic pathway in order to detect and localize disease. Its results can be used to help decide on the indication, type, and localization of a prostate biopsy for cancer diagnosis. In addition, mpMRI has the potential to contribute information on the characterization, or aggressiveness, of detected cancers including tumor progression over time. There is considerable variation in the way results of different MRI sequences are reported. We conducted a review of scoring systems that have been used in the detection and characterization of prostate cancer. This revealed that existing scoring and reporting systems differ in purpose, scale, and range. We evaluate these differences in this review. This first step in collating all methods of scoring and reporting mpMRI will ultimately lead to consensus approaches to develop a standardized reporting scheme that can be widely adopted and validated to ensure comparability of research outputs and optimal clinical practice.
    Journal of Magnetic Resonance Imaging 05/2012; · 2.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This retrospective study compares dynamic contrast-enhanced (DCE) MRI with the serial prostate-specific antigen (PSA) measurement for detection of residual disease following whole-gland high-intensity focused ultrasound (HIFU) therapy of prostate cancer. Patients in whom post-HIFU DCE-MRI was followed within 3 months by ultrasound-guided transrectal biopsy were selected from a local database. 26 patients met the study inclusion criteria. Serial PSA levels following HIFU and post-HIFU follow-up MRI were retrieved for each patient. Three radiologists unaware of other investigative results independently assessed post-HIFU MRI studies for the presence of cancer, scoring on a four-point scale (1, no disease; 2, probably no disease; 3, probably residual disease; and 4, residual disease). Sensitivity, specificity and receiver operating characteristic (ROC) analysis were performed for each reader, post-HIFU PSA nadir and pre-biopsy PSA level thresholds of >0.2 and >0.5 ng ml(-1). The sensitivity of DCE-MRI for detection of residual disease for the three readers ranged between 73% and 87%, and the specificity between 73% and 82%. There was good agreement between readers (κ = 0.69-0.77). The sensitivity and specificity of PSA thresholds was 60-87% and 73-100%, respectively. The area under the ROC curve was greatest for pre-biopsy PSA (0.95). DCE-MRI performed following whole-gland HIFU has similar sensitivity and specificity and ROC performance to serial PSA measurements for detection of residual or recurrent disease.
    The British journal of radiology 01/2012; 85(1014):720-8. · 2.11 Impact Factor
  • European Journal of Cancer 09/2011; 47. · 5.06 Impact Factor
  • European Urology Supplements 03/2011; 185(4). · 3.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Bone scintigraphy (BS) lacks sensitivity for detecting very early skeletal metastases (SM) in prostate cancer (PC) and is often limited by poor specificity. Also scintigraphic flare of SM can occur following effective treatment and mislead an early response assessment. We hypothesised that a flare reaction might amplify the signal from subclinical SM, increasing the sensitivity of BS and that the phenomenon may be specific for metastases. We conducted a prospective study to determine the frequency of the flare phenomenon in patients with metastatic PC starting hormone therapy and to explore its utility in patients with negative staging scans but considered at high risk of SM and in those with equivocal baseline BS abnormalities. Ninety-nine patients commencing first-line hormone therapy had repeat BS at 6 weeks to score a flare reaction. Of 22 patients with unequivocal SM on the baseline scan, a flare occurred in 9 (41%). Of 36 high-risk localised prostate cancer patients with normal BS pre-treatment, the scan became positive for metastases at 6 weeks in 4 (11%). Of 41 patients with pre-treatment scintigraphic abnormalities of uncertain aetiology, a flare occurred in 8 cases (20%). All eight were confirmed to have SM by follow-up and imaging. Of the 33 remaining patients without a flare, 2 developed SM at 14 months and the remainder did not develop SM in a median follow-up period of 36 months. The flare phenomenon following initial hormone therapy can be used to improve both sensitivity and specificity of BS in PC.
    European Journal of Nuclear Medicine 01/2011; 38(1):7-13. · 4.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Multiparametric magnetic resonance imaging (mpMRI) may have a role in detecting clinically significant prostate cancer in men with raised serum prostate-specific antigen levels. Variations in technique and the interpretation of images have contributed to inconsistency in its reported performance characteristics. Our aim was to make recommendations on a standardised method for the conduct, interpretation, and reporting of prostate mpMRI for prostate cancer detection and localisation. A consensus meeting of 16 European prostate cancer experts was held that followed the UCLA-RAND Appropriateness Method and facilitated by an independent chair. Before the meeting, 520 items were scored for "appropriateness" by panel members, discussed face to face, and rescored. Agreement was reached in 67% of 260 items related to imaging sequence parameters. T2-weighted, dynamic contrast-enhanced, and diffusion-weighted MRI were the key sequences incorporated into the minimum requirements. Consensus was also reached on 54% of 260 items related to image interpretation and reporting, including features of malignancy on individual sequences. A 5-point scale was agreed on for communicating the probability of malignancy, with a minimum of 16 prostatic regions of interest, to include a pictorial representation of suspicious foci. Limitations relate to consensus methodology. Dominant personalities are known to affect the opinions of the group and were countered by a neutral chairperson. Consensus was reached on a number of areas related to the conduct, interpretation, and reporting of mpMRI for the detection, localisation, and characterisation of prostate cancer. Before optimal dissemination of this technology, these outcomes will require formal validation in prospective trials.
    European Urology 12/2010; 59(4):477-94. · 10.48 Impact Factor
  • Gynecologic Oncology. 03/2010; 116(3):S94-S95.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Magnetic resonance imaging (MRI) provides superior diagnostic accuracy over computed tomography (CT) in oropharyngeal tumours. Precise delineation of the gross tumour volume (GTV) is mandatory in radiotherapy planning when a GTV boost is required. CT volume definition in this regard is poor. We studied the feasibility of using flexible surface (flex-L) coils to obtain MR images for MR-CT fusion to assess the benefit of MRI over CT alone in planning base of tongue tumours. Eight patients underwent CT and MRI radiotherapy planning scans with an immobilisation device. Distortion-corrected T1-weighted post-contrast MR scans were fused to contrast-enhanced planning CT scans. GTV, clinical target and planning target volumes (CTV, PTV) and organs at risk (OAR) were delineated on CT, then on MRI with blinding to the CT images. The volumetric and spatial differences between MRI and CT volumes for GTV, CTV, PTV and OAR were compared. MR image distortions due to field inhomogeneity and non-linear gradients were corrected and the need for such correction was evaluated. The mean primary GTV was larger on MRI (22.2 vs. 9.5 cm(3), p=0.05) than CT. The mean primary and nodal GTV (i.e. BOT and macroscopic nodes) was significantly larger on MRI (27.2 vs. 14.4 cm(3), p=0.05). The volume overlap index (VOI) between MRI and CT for the primary was 0.34 suggesting that MRI depicts parts of the primary tumour not detected by CT. There was no significant difference in volume delineation between MR and CT for CTV, PTV, nodal CTV and nodal PTV. MRI volumes for brainstem and spinal cord were significantly smaller due to improved organ definition (p=0.002). Susceptibility and gradient-related distortions were not found to be clinically significant. MRI improves the definition of tongue base tumours and neurological structures. The use of MRI is recommended for GTV dose-escalation techniques to provide precise depiction of GTV and improved sparing of spinal cord and brainstem.
    Radiotherapy and Oncology 02/2010; 94(2):161-7. · 4.52 Impact Factor
  • Source
    Liam Welsh, Aslam Sohaib, Nicholas van As
    [Show abstract] [Hide abstract]
    ABSTRACT: Prostate cancer is the commonest non-cutaneous cancer in men, and is increasingly being diagnosed at earlier stages due to the routine use of PSA testing. This poses the dilemma of which men with early stage prostate cancer require radical treatments with their attendant morbidities, as many of these cancers will be clinically insignificant. MRI techniques for imaging prostate cancer are now in routine clinical use, yet the optimum use of prostate MRI has yet to be clearly defined. MRI techniques for imaging the prostate continue to evolve and in addition to the detailed anatomical information available from classical MRI sequences, newer functional MRI methods are now available which may be able to provide additional valuable clinical information on the location and nature of localised prostate cancers. MRI techniques offer the possibility of being able to help select those men with localised prostate cancer that require radical treatments, and also to help in the delivery of these treatments. The current status of MRI techniques in the management of prostate cancer is reviewed, with an emphasis on the potential future contribution of functional MRI methods to clinical practice.
    Urological Cancer Abstracts. 01/2010;
  • [Show abstract] [Hide abstract]
    ABSTRACT: To assess the surgical anatomy knowledge of gynaecological oncology (GO) trainees and to evaluate the impact of a cadaveric dissection course on postgraduate surgical training. An intensive 3-day cadaveric dissection course with illustrated lectures and supervised dissection, with a multiple-choice questionnaire (MCQ) on surgical anatomy at the beginning and end of the course was organised in the Anatomy Facility of a London Medical School. Each cadaver was embalmed with a mixture of alcohol, phenol and glycerol ("soft-preserved") rather than fixed in formalin, to more closely preserve in vivo conditions of the body. There were ten dissecting delegates, two per cadaver. The delegates dissected the abdomen and pelvis with the emphasis on surgical approaches rather than the classical descriptive anatomy approaches. Delegates also completed a course evaluation. Without negative marking, the mean initial MCQ score was 57%, and final mean score 64%. With negative marking, the mean initial score was 43%, and mean final score 53%. Delegates rated the course highly, would recommend it to other trainees and considered that such a course should be incorporated into subspecialty training. The surgical anatomy knowledge of subspecialty trainees was weak but improved as a result of the dissection course. The most positive finding was the course evaluation. Postgraduate surgical training in GO would likely be enhanced by, and arguably requires, cadaveric dissection. "Soft-preserved" rather than formalin-fixed cadavers should be used.
    Gynecologic Oncology 04/2009; 113(3):352-6. · 3.93 Impact Factor
  • European Urology Supplements - EUR UROL SUPPL. 01/2009; 8(4):322-322.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hypoxia in patients with head-and-neck cancer (HNC) is well established and known to cause radiation resistance and treatment failure in the management of HNC. This study examines the role of parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perfusion computed tomography (CT) as surrogate markers of intratumoral hypoxia, defined by using the exogenous marker of hypoxia pimonidazole and the endogenous marker carbonic anhydrase 9 (CA9). Patients with HNC underwent preoperative DCE-MRI, perfusion CT, and pimonidazole infusion. Imaging parameters were correlated with pimonidazole and CA9 staining. The strength of correlations was tested by using a two-tailed Spearman's rank correlation coefficient. Twenty-three regions of interest were analyzed from the 7 patients who completed the DCE-MRI studies. A number of statistically significant correlations were seen between DCE-MRI parameters (volume transfer between blood plasma and extracellular extravascular space [EES], volume of EES, rate constant between EES and blood plasma, time at arrival of contrast inflow, time to peak, average gradient, and time to onset) and areas with a pimonidazole score of 4. In the case of CA9 staining, only a weak correlation was shown with wash-in rate. There were no significant correlations between perfusion CT parameters and pimonidazole staining or CA9 expression. Intratumoral hypoxia in patients with HNC may be predicted by using DCE-MRI; however, perfusion CT requires further investigation.
    International journal of radiation oncology, biology, physics 12/2008; 74(1):29-37. · 4.59 Impact Factor

Publication Stats

298 Citations
77.47 Total Impact Points

Institutions

  • 2012
    • The Royal Marsden NHS Foundation Trust
      Londinium, England, United Kingdom
    • Royal College of Surgeons of England
      Londinium, England, United Kingdom
  • 2010
    • University College London
      • Division of Surgery and Interventional Science
      London, ENG, United Kingdom