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Papers by Gagan Prakash

Indian Journal of Urology

Malignant penile neoplasms are commonly squamous etiology, with the inguinal nodes being the firs... more Malignant penile neoplasms are commonly squamous etiology, with the inguinal nodes being the first echelon of spread. The disease spreads to the pelvic lymph nodes only after metastases to the groin nodes, and this is the most important prognostic factor in penile carcinoma. While treatment of penile carcinoma with proven metastases to the inguinal lymph nodes mandates ilioinguinal lymph node dissection, the treatment of patients with impalpable nodes is more controversial. Overtreatment leads to excessive treatment-related morbidity in these patients, while a wait-and-see policy runs the risk of patients presenting with inguinal and distant metastases, which would have been curable at presentation. Unfortunately, no single imaging modality has been proved to be convincingly superior in the staging, and hence, management of the clinically negative groin has been subject to debate. While some high volume centers have promoted the use of dynamic sentinel lymph node biopsy, others advocate the use of the modified inguinal lymph node template to stage the groin adequately. Newer techniques such as video endoscopic inguinal lymph node dissection have been introduced as an alternative to the original radical inguinal lymphadenectomy to reduce morbidity.

Indian Journal of Cancer

To gain insights on the diverse practice patterns and treatment pathways for prostate cancer (PC)... more To gain insights on the diverse practice patterns and treatment pathways for prostate cancer (PC) in India, the Urological Cancer Foundation convened the first Indian survey to discuss all aspects of PC, with the objective of guiding clinicians on optimizing management in PC. A modified Delphi method was used, wherein a multidisciplinary panel of oncologists treating PC across India developed a questionnaire related to screening, diagnosis and management of early, locally advanced and metastatic PC and participated in a web–based survey (WBS) (n = 62). An expert committee meeting (CM) (n = 48, subset from WBS) reviewed the ambiguous questions for better comprehension and reanalyzed the evidence to establish a revote for specific questions. The threshold for strong agreement and agreement was ≥90% and ≥75% agreement, respectively. Sixty-two questions were answered in the WBS; in the CM 31 questions were revoted and 4 questions were added. The panelists selected answers based on their best opinion and closest to their practice strategy, not considering financial constraints and access challenges. Of the 66 questions, strong agreement was reached for 17 questions and agreement was achieved for 22 questions. There were heterogeneous responses for 27 questions indicative of variegated management approaches. This is one of the first Indian survey, documenting the diverse clinical practice patterns in the management of PC in India. It aims to provide guidance in the face of technological advances, resource constraints and sparse high-level evidence..

Clinical Genitourinary Cancer

Cancer Medicine

BackgroundTo assess urinary symptoms and urine cytology as screening tools for cystoscopic detect... more BackgroundTo assess urinary symptoms and urine cytology as screening tools for cystoscopic detection of local recurrence after bladder‐preserving trimodality treatment (TMT).MethodsPatients with muscle‐invasive bladder cancer receiving definitive TMT follow‐up three monthly for 2 years, six monthly for the next 3 years and then yearly, with a clinical review, urine cytology and cystoscopy at each visit (triple assessment, TA). Grade 2+ cystitis/haematuria absent/present was scored 0/1, and urine cytology reported negative/suspicious or positive was scored 0/1, respectively. The performance of these two parameters for predicting local recurrence in cystoscopic biopsy was tested. Other hypothetical surveillance schedules included cystoscopy on alternate visits (COAV), or suspected recurrence (COSR), six‐monthly COSR and six‐monthly TA.ResultsA total of 630 follow‐up visits in 112 patients with 19 recurrences (7 muscle invasive, 12 non‐muscle invasive) at a median follow‐up of 19 month...

Practical Radiation Oncology

Indian Journal of Urology, 2021

Introduction: The grading system of chromophobe renal cell carcinoma (ChRCC) is not well establis... more Introduction: The grading system of chromophobe renal cell carcinoma (ChRCC) is not well established. In this study, we aimed to compare the application of Fuhrman nuclear grade (FNG) with the novel chromophobe tumor grade (CTG). We also evaluated the correlation of these two grading systems with the clinical outcome. Materials and Methods: Consecutive cases of ChRCC diagnosed on nephrectomy during 2005–2014 were identified. The clinical details of the patients were retrieved. Histopathology slides were reviewed and the nuclear grading was assigned using standard FNG and the CTG system. The CTG and FNG gradings were correlated with clinical outcome. Results: A total of 80 cases were retrieved. Distribution of FNG was as follows: FNG-1, 1 (1.3%); FNG-2, 23 (28.3%); FNG-3, 44 (55.0%); and FNG-4, 12 (15%). CTG distribution was as follows: CTG-1, 48 (60.0%); CTG-2, 20 (25.0%); and CTG-3 12 (15.0%). Follow-up data was available in 46 cases; the median follow-up was 23.9 months (range 1–96.4 months). The median time to recurrence/metastasis was 17.2 months (range 3.2–31.2 months). Mean disease-free survival (DFS) was 68.5 months. Both CTG (P < 0.001) and FNG (P = 0.001) correlated with DFS; however, only CTG retained this significance when only the nonsarcomatous cases were analyzed. On receiver operating characteristics curve analysis, CTG had higher predictive accuracy for DFS for the entire group, while FNG lost the statistical significance when the nonsarcomatous cases were analyzed. CTG (P = 0.001) but not FNG (P = 0.106) correlated with the disease-specific adverse events in non-sarcomatous cases. Conclusions: It is possible to apply CTG in ChRCC. It is a better predictor of DFS and disease-specific adverse events. CTG is more appropriate and applicable than the FNG in grading ChRCC.

Cancer Research, Statistics, and Treatment, 2020

Journal of Clinical Oncology, 2021

PURPOSE We report the clinical outcomes of a randomized trial comparing prophylactic whole-pelvic... more PURPOSE We report the clinical outcomes of a randomized trial comparing prophylactic whole-pelvic nodal radiotherapy to prostate-only radiotherapy (PORT) in high-risk prostate cancer. METHODS This phase III, single center, randomized controlled trial enrolled eligible patients undergoing radical radiotherapy for node-negative prostate adenocarcinoma, with estimated nodal risk ≥ 20%. Randomization was 1:1 to PORT (68 Gy/25# to prostate) or whole-pelvic radiotherapy (WPRT, 68 Gy/25# to prostate, 50 Gy/25# to pelvic nodes, including common iliac) using computerized stratified block randomization, stratified by Gleason score, type of androgen deprivation, prostate-specific antigen at diagnosis, and prior transurethral resection of the prostate. All patients received image-guided, intensity-modulated radiotherapy and minimum 2 years of androgen deprivation therapy. The primary end point was 5-year biochemical failure-free survival (BFFS), and secondary end points were disease-free surviv...

Radiotherapy and Oncology, 2020

Aim: To report toxicity and quality of life (QOL) outcomes from a randomised trial of prostate on... more Aim: To report toxicity and quality of life (QOL) outcomes from a randomised trial of prostate only versus whole pelvic radiotherapy in high risk, node negative prostate cancer. Materials/methods: Patients with localised prostate adenocarcinoma and nodal involvement risk > 20%, were randomised to prostate only (PORT, 68 Gy/25# to prostate) and whole pelvis (WPRT, 68 Gy/25# to prostate and 50 Gy/25# to pelvis) arms with stratification for TURP, Gleason score, baseline PSA, and type of androgen deprivation therapy (ADT). Image guided intensity modulated radiotherapy (IG-IMRT) and two years of ADT were mandatory. Acute and late genitourinary (GU) and gastrointestinal (GI) toxicities were graded using RTOG grading. QOL was assessed using EORTC QLQ-C30 and PR-25 questionnaire pre-treatment and every 3-6 months post RT. Results: Total 224 patients were randomised (PORT 114, WPRT 110) from November 2011 to August 2017. Median follow up was 44.5 months. No RTOG grade IV toxicity was observed. Acute GI and GU toxicities were similar between both the arms. Cumulative ! grade II late GI toxicity was similar for WPRT and PORT (6.5% vs. 3.8%, p = 0.39) but GU toxicity was higher (17.7% vs. 7.5%, p = 0.03). Dosimetric analysis showed higher bladder volume receiving 30-40 Gy in the WPRT arm (V30, 60% vs. 36%, p < 0.001; V40, 41% vs. 25%, p < 0.001). There was no difference in QOL scores of any domain between both arms. Conclusion: Pelvic irradiation using hypofractionated IG-IMRT resulted in increased grade II or higher late genitourinary toxicity as compared to prostate only RT, but the difference was not reflected in patient reported QOL. Clinicaltrials.gov NCT02302105: Prostate Only or Whole Pelvic Radiation Therapy in High Risk Prostate Cancer (POP-RT).

Frontiers in Oncology, 2019

Practical Radiation Oncology, 2019

To determine the genitourinary (GU) toxicity outcomes in prostate cancer patients treated with st... more To determine the genitourinary (GU) toxicity outcomes in prostate cancer patients treated with stereotactic body radiation therapy (SBRT) who have undergone a prior transurethral resection of prostate (TURP) and compare it to a similar non-TURP cohort. Materials and Methods: Fifty prostate cancer patients who had undergone a single TURP, had a good baseline urinary function, and had been subsequently treated with SBRT were chosen from a prospectively maintained database. These were propensity score matched to a similar non-TURP cohort treated during the same period. Matching was done for diabetes mellitus and volume of radiation therapy. Acute GU and late GU toxicity were scored using the Radiation Therapy Oncology Group (RTOG) criteria. Stricture and incontinence were scored using Common Terminology for Common Adverse Events version 4.0. Results: Median follow-up for the entire cohort was 26 months (non-TURP vs TURP, 30 months vs 22 months, P Z .34). The median duration between TURP and start of SBRT was 10 months. There was no significant difference between non-TURP versus TURP cohort in terms of RTOG acute GU toxicities grade !2 (8% vs 6%, P Z .45), RTOG late GU toxicities grade !2 (8% vs 12%, P Z .10), stricture rates (4% vs 6%, P Z .64), and incontinence rates (0% vs 4%, P Z .15). The median duration of time to late toxicity was 16 months vs 10 months (P Z .12) in non-TURP and TURP cohort, respectively.

The Journal of Urology, 2018

, we selected those who performed an early scan for the detection of prostate fossae recurrences ... more , we selected those who performed an early scan for the detection of prostate fossae recurrences and had a PSA levels <2 ng/mL at PET time. 75 subjects met the inclusion criteria. All these patients underwent an early static (after 2 minutes from the FCH injection; 1 bed; 5 minutes/bed) and late whole-body (after 60 minutes from FCH injection; 7 beds; 3 minutes/ bed) PET/CT acquisition. A correlation among terapeutic factors, Gleason Score, PSA levels, PSA doubling time (PSAdt), PSA velocity (PSA vel) and early PET/CT findings were assessed by using the chisquare test and Mann-Whitney test. The agreement between early and late PET/CT acquisitions was studied by K-statistic. ROC analysis was used to evaluate the optimal cutoff point for PSA able to distinguish positive and negative PET/CT finding. A p<0.05 was considered statistically significant. RESULTS: PET/CT showed a pathological tracer uptake in 25 patients (33.3%); in 15 cases confined to the prostatic bed, in 4 to lymph nodes, in 4 to the bone, in 2 to both prostatic fossae and lymph nodes and in 3 to both bone and lymph nodes. Therefore, the detection rate of PET/CT was higher for local recurrences (18/25; 72%). PSA values increased in patients with a positive PET/CT finding compared to subjects with a negative scan. Similarly, PSAdt and PSAvel values were different between patients with a positive and a negative PET/CT scan (6.9 versus 10.2 mo and 0.6 versus 0.4 ng/mL/year, respectively). 15 patients had positive early scans and only 4/15 were positive for both early and late PET/CT acquisition (Kappa value ¼ 0.368; p< 0.001). No correlation was found between the PSAdt or PSAvel and positive or negative early PET/CT images. At ROC analysis a PSA value of 0.67 ng/mL showed a sensitivity and specificity of 69% and 64%, respectively, to distinguish patients with positive or negative PET findings. Using this cutoff value, FCH PET/CT was positive in 23% of patients with PSA < 0.67 ng/mL; 12% of patients had a positive early PET/CT and therefore 88% had negative early scans. CONCLUSIONS: From this study emerges that, in patients with PSA < 2 ng/mL, local recurrence is more often detect by FCH PET/CT finding. An early PET acquisition is able to improve the detection rate, expecially in prostatic fossae, and we reported in this study that local findings were increased to 70%. Our results suggest that the selection of patients ungergoing a "dual phase" PET/CT should be based not only on PSA value but also on PSA kinetic.

Indian journal of cancer

The stage at diagnosis of renal cell cancer (RCC) in developed countries is lower due to increase... more The stage at diagnosis of renal cell cancer (RCC) in developed countries is lower due to increased utilization of routine health checkups by patients compared to developed countries. This study aims to determine the sociodemographic and clinical distribution of RCC in patients presenting to Tata Memorial Hospital (TMH). We performed a retrospective audit of all patients presenting to TMH with a diagnosis of RCC. Data were retrieved from our electronic medical record system from January 1, 2013 to December 31, 2013. The survival analysis was done by Kaplan-Meir analysis method of estimating survival. Log-rank test of comparison was applied to estimate the difference in the survival among the different stages of renal cancer. Of the 35,197 new registered patients at TMH, 338 were diagnosed with RCC. Most patients were in the 50-60 years age group, with 56.6 years being the median age at presentation. Among patients treated at TMH, 84 underwent surgery and tyrosine kinase inhibitor was...

Journal of medical imaging and radiation oncology, Jan 5, 2017

Although few studies have demonstrated utility of (18) F- fluoro-2-deoxy-d-glucose positron emiss... more Although few studies have demonstrated utility of (18) F- fluoro-2-deoxy-d-glucose positron emission tomography/computerised tomography ((18) F-FDG PET/CT) in benign pheochromocytoma/paragangliomas (PCC/PGLs), there limited data on factors predicting the FDG uptake in PCC/PGL. The study was conducted at a tertiary health care centre. In addition to the routine investigations, all patients (n = 96) with PCC/PGL were evaluated with (18) F-FDGPET/CT and majority (n = 78) underwent (131) I-metaiodobenzyl guanidine ((131) I-MIBG) scintigraphy. Forty-three patients also underwent testing for germline mutations in five PCC/PGL susceptibility genes (VHL, RET, SDHB, SDHC and SDHD) and all patients were evaluated clinically for neurofibromatosis-1. The study included 96 patients with PCC/PGL(82 benign and 14 malignant). FDGSUVmax was significantly higher for malignant than benign PCC/PGL(P = 0.009) and for extra-adrenal PGL than adrenal PCC (P = 0.017). In subgroup analysis, metanephrine-secr...

South Asian Journal of Cancer, 2016

Tumors of the genitourinary system are one of the most common tumors encountered in clinical prac... more Tumors of the genitourinary system are one of the most common tumors encountered in clinical practice. The associated morbidity and mortality and the significant proportion of affected middle-age individuals have a major bearing on the death-adjusted life years compared to other malignancies. Genitourinary system tumors encompass a very broad spectrum with regard to age, location, histology, and clinical outcomes. Advances in diagnostic imaging, surgical techniques, radiotherapy equipment, and generation of newer chemotherapeutic and targeted agents over the past few years have helped improving treatment outcome. Several focused groups within India have been working on a range of topics related to genitourinary system tumors, and a significant body of work from India in the recent years is being increasingly recognized throughout the world. The present article summarizes the key published work related to the epidemiology of genitourinary system tumors in the Indian setting. A PubMed...

Indian Journal of Urology, 2015

Radical cystectomy is the standard treatment for muscle invasive bladder cancer. Lymphocele is a ... more Radical cystectomy is the standard treatment for muscle invasive bladder cancer. Lymphocele is a common sequalae of pelvic lymphadenectomy. We report an unusual presentation of pelvic lymphocele developing after radical cystectomy reconstructed with an ileal conduit where the patient developed obstruction of the ileal conduit loop due to external pressure of the lymphocele. Catheter drainage of the conduit relieved the symptoms and a computerized tomography scan showed a large lymphocele causing acute angulation and resultant obstruction of the ileal conduit. The patient was treated with percutaneous drainage of the lymphocele and remains symptom-free on follow-up at 1 year.

Indian journal of urology : IJU : journal of the Urological Society of India, 2008

Indian Journal of Urology, 2013

Bone health is affected in patients with prostate cancer, both by the disease and its treatment. ... more Bone health is affected in patients with prostate cancer, both by the disease and its treatment. Metastases to bone leads to pain, fractures, and spinal cord compression; bone loss due to androgen deprivation therapy (ADT) leads to osteoporosis and its complications. Both these scenarios are a major cause of morbidity and adversely affect the quality of life of these patients. Maintaining an optimum bone health throughout the natural course of prostate cancer is an important aspect in the management of this disease. An understanding of the complex interplay between osteoclasts, osteoblasts, receptor activator of nuclear factor B (RANK), and various other tyrosine kinases involved in the pathophysiology of bone metastases is essential. Zoledronic acid (ZA), an intravenously administered bisphosphonate, and Denosumab, a subcutaneously administered inhibitor of nuclear factor B ligand (RANKL), have already been approved by Food and Drug Administration (FDA) for their use in treatment of bone metastases. This article discusses the pathophysiology of bone metastases and bone loss due to ADT in prostate cancer, role of biomarkers, newer modalities of imaging, World Health Organization (WHO)/FRAX nomogram in evaluation of these patients, utility of currently available drugs and evidence supporting their use, and newer therapeutic agents like alpha-emitting Radium-223, endothelin-A receptor antagonists (Atrasentan and Zibotentan) and the proto-oncogene tyrosine-protein kinase (SRC) inhibitor, Dasatinib.