1657 Resected Gastric Adenocarcinomas at a Single Institution: Outcomes and Trends over 17 Years.

BACKGROUND: Outside of clinical trials, real-world data of advanced gastric cancers (AGCs) managed with perioperative or adjuvant chemotherapy with a backbone of D2 lymphadenectomy is limited. PATIENTS AND METHODS: Curative resections for gastric adenocarcinoma between January 2003 and January 2020 at the Tata Memorial Centre were analyzed, comparing three time periods marking major increments in annual gastric resections (GRs). RESULTS: 1657 radical gastric resections were performed with a morbidity and mortality rate of 34.9% and 1.4%, respectively. Over three consecutive periods, the number of annual GRs increased from 56/year to 97/year to 156/year (P < 0.001) with a significant escalation in surgical magnitude and complexity. Improvement in surgical quality indicators (median lymph node yield from 15 to 25, P < 0.001 and margin negativity from 8.2 to 5.5%, P = 0.002) was observed with no corresponding increase in severe complications (6.9%) or mortality (1.4%). The proportion of distal and signet ring cancers was found to decrease over time, with an increase in proximal cancers and younger age at presentation. Overall, 90% of GRs were for AGCs with a median overall survival (OS) of 4.4 years (± 6 months), and 5-year OS rate of 47.6% (± 1.9%). CONCLUSIONS: Change in pattern of tumor characteristics was observed. Aggressive treatment options for AGC were employed progressively with excellent survival. With increase in volumes, improvements in surgical quality indicators, and a relative improvement in postoperative mortality was observed. These results provide a roadmap for developing dedicated gastric cancer centers.

Long-Term Follow-Up Data of Tumor-Induced Osteomalacia Managed with Surgery and/or Radiofrequency Ablation from a Single Center.

Data on radiofrequency ablation (RFA) in tumor-induced osteomalacia (TIO) are restricted to case reports (~ 11 patients) and long-term follow-up data are further scarce. We describe our experience on managing TIO from a tertiary care center in India. Retrospective study of patients with localized TIO was performed and clinical, biochemical, treatment and follow-up details were retrieved. Normalization of serum phosphorus in absence of phosphate supplementation was defined as remission. Of 33 patients (23 males), 24 patients underwent surgery as first-line treatment, and early remission, delayed remission (> 1 month for phosphorus normalization) and persistence were observed 12, 3, and 9 patients at a median follow-up of 5 (4-9) years. The gender, age, tumor size, location of tumors and FGF23 levels were not statistically different in patients who were in remission after surgery versus those with persistent disease. Second/third line treatment included conventional medical treatment and/or repeat surgery (n = 3), radiotherapy (n = 3), peptide receptor radionuclide therapy (n = 1), RFA (n = 1). Two patients had transient worsening (weeks) of weakness post-surgery. 10 patients underwent RFA (first-line n = 9); at the last follow-up 5 (4-10) years, 7 are in remission. Two of three persistent disease patients had large tumors (5.6 and 3.6 cm). There were no RFA-related complications except local ulcer in one. Although persistent disease was present in a few patients in both arms, there was no recurrence in either RFA or surgical cohort. RFA provide durable response similar to surgery, persistence requires multi-modality treatment.

Accuracy of contrast-enhanced CT in liver neoplasms in children under 2 years age.

BACKGROUND: Multiple differentials exist for pediatric liver tumors under 2 years. Accurate imaging diagnosis may obviate the need for tissue sampling in most cases. OBJECTIVE: To evaluate the imaging features and diagnostic accuracy of computed tomography (CT) in liver tumors in children under 2 years. METHODS: Eighty-eight children under 2 years with treatment naive liver neoplasms and baseline contrast-enhanced CT were included in this institutional review board approved retrospective study. Two blinded onco-radiologists assessed these tumors in consensus. Findings assessed included enhancement pattern, lobulated appearance, cystic change, calcifications, central scar-like appearance, and metastases. The radiologists classified the lesion as hepatoblastoma, infantile hemangioma, mesenchymal hamartoma, rhabdoid tumor, or indeterminate, first based purely on imaging and then after alpha-fetoprotein (AFP) correlation. Multivariate analysis and methods of comparing means and frequencies were used for statistical analysis wherever applicable. Diagnostic accuracy, sensitivity, and positive predictive values were analyzed. RESULTS: The mean age of the sample was 11.4 months (95% CI, 10.9-11.8) with 50/88 (57%) boys. The study included 72 hepatoblastomas, 6 hemangiomas, 4 mesenchymal hamartomas, and 6 rhabdoid tumors. Presence of calcifications, multilobular pattern of arterial enhancement, lobulated morphology, and central scar-like appearance was significantly associated with hepatoblastomas (P-value < 0.05). Fourteen out of eighty-eight lesions were called indeterminate based on imaging alone; six lesions remained indeterminate after AFP correlation. Pure radiology-based diagnostic accuracy was 81.8% (95% CI, 72.2-89.2%), which increased to 92.1% (95% CI, 84.3-96.7%) (P-value > 0.05) after AFP correlation, with one hepatoblastoma misdiagnosed as a rhabdoid tumor. If indeterminate lesions were excluded for biopsy, the accuracy would be 98.8% (95% CI, 93.4-99.9%). CONCLUSION: CT had high accuracy for diagnosing liver neoplasms in the under 2-year age population after AFP correlation. Certain imaging features were significantly associated with the diagnosis of hepatoblastoma. A policy of biopsying only indeterminate lesions after CT and AFP correlation would avoid sampling in the majority of patients.

Cross-sectional imaging review of common to uncommon lung cancer mimickers in a tertiary care oncology center.

Lung cancer is the most diagnosed cancer worldwide. Many non-malignant pulmonary lesions, such as tuberculosis, fungal infection, organizing pneumonia, inflammatory myofibroblastic tumor, and IgG4 disease, can mimic lung cancer due to their overlapping morphological appearance on imaging. These benign entities with minor differentiating imaging clues may go unnoticed in a high-volume cancer institution, leading to over-investigation that may result in repeated biopsies, pointless wedge resections, and related morbidities. However, with a thorough medical history, laboratory diagnostic work-up, and careful analysis of imaging findings, one can occasionally restrict the range of possible diagnoses or arrive at a definitive conclusion. When imaging features overlap, image-guided lung sampling is crucial since histopathological analysis is the gold standard.

Imaging of central nervous system emergencies in oncology.

Central nervous system (CNS) may be predisposed to devastating complications in cancer patients which may add to morbidity and mortality in this group. Majority of the complications are vascular in nature due to the altered coagulation profile and pro-inflammatory state in these patients. However, there are a host of other conditions which may affect the clinical course of these patients including metabolic and toxic encephalopathies, infections, and paraneoplastic syndromes. Moreover, multimodality management of these patients, which is often used in majority of the cancers, exposes them to treatment related complications. This pictorial review aims to enlighten the reader regarding the various complications affecting the CNS as seen at our tertiary cancer care institute. We aim to highlight the emergent nature of these complications and the need to identify them quickly and accurately on imaging which helps to institute early appropriate management and prevents further morbidity and mortality.

Leiomyosarcoma of inferior vena cava (IVC): do we really need to reconstruct IVC post resection? Single institution experience.

BACKGROUND: Inferior vena cava (IVC) leiomyosarcomas (LMS) are a rare group of retroperitoneal tumors. R0 surgical resection is the only curative modality of treatment. IVC resection for retroperitoneal sarcoma is a complex surgery with no definitive guidelines for reconstruction. METHODS: Retrospective review of all patients who underwent surgical resection of primary leiomyosarcoma of the IVC requiring resection from 2010 to 2020 at our tertiary care center was performed. RESULTS: Among 24 patients who required IVC resection for LMS, only 7 (29%) required reconstruction of IVC. According to Clavien-Dindo classification, there was one grade 3 or more morbidity and 1 post-operative mortality. Seventeen patients underwent R0 resection whereas 7 patients had R1 resection on final histopathology. At a median follow-up of 25 months (range 8-91 months), the median OS was 40 months with median DFS of 28 months. Two patients presented with local recurrence while 13 patients developed systemic recurrence on follow-up. CONCLUSION: Careful preoperative multidisciplinary planning can make IVC resection without reconstruction feasible with acceptable perioperative morbidity, mortality, and oncological outcomes for IVC LMS.

Percutaneous Radiofrequency Ablation of Appendicular Skeleton Chondroblastoma-an Experience from a Tertiary Care Cancer Center.

PURPOSE: To evaluate safety and long-term efficacy of radiofrequency (RF) ablation in treatment of chondroblastoma. MATERIALS AND METHODS: This retrospective analysis comprised 27 consecutive patients with histopathologically proven chondroblastoma treated by RF ablation. The tumors were located in the proximal humerus (n = 6), proximal tibia (n = 8), proximal femur (n = 6), distal femur (n = 5), acromion process (n = 1), and lunate (n = 1). In 19 patients (70.3%), the tumor was in the weight-bearing area of the bone. Clinical response was assessed by comparing pain scores and functional assessment by Musculoskeletal Tumor Society (MSTS) score before and after ablation. Patients were followed for a minimum of 1 year to rule out complications and recurrence. RESULTS: Technical success rate was 100%. Mean pain score before the procedure was 7.34 (range, 7-9); all patients experienced a reduction in pain, with 25 (92.6%) patients reporting complete pain relief at 6 weeks. Mean MSTS score before the procedure was 15.4, whereas mean MSTS score at 6 weeks after the procedure was 28.6, suggesting significant functional improvement (P < .0001). Two patients developed osteonecrosis and collapse of the treated bone. There were no recurrences. CONCLUSIONS: Percutaneous RF ablation is a safe and effective option for treating chondroblastoma of the appendicular skeleton.

Towards standardization of management of gallbladder carcinoma with obstructive jaundice: Analysis of 113 cases over 10 years at a single institution.

BACKGROUND: Presence of jaundice in gallbladder carcinoma (GBC) is considered a sign of inoperability with no defined treatment pathways. METHODS: Retrospective analysis of all surgically treated GBC patients from January 2010 to December 2019 was performed for evaluating etiology of obstructive jaundice, resectability, postoperative morbidity, mortality, disease-free survival (DFS) and overall survival (OS). RESULTS: Out of 954 patients, 521 patients (54.61%) were locally advanced gallbladder carcinoma (LAGBC: Stage III and IV) and 113 patients (11.84%) had jaundice at presentation. Thirty-four (30%) patients had benign cause of obstructive jaundice. Median OS of the whole cohort (n=113) was 22 months (16.5-27.49 months) with resectability rate of 62% (70/113). Median OS of curative resection group (n=70) was 32 months and DFS was 25 months. Treatment completion was achieved in 30% (n= 21/70) patients with median OS of 46 months and median DFS of 27 months. Isolated bile duct infiltration subgroup fared the best with median OS of 74 months with a 5-year survival of 66.7%. CONCLUSION: Surgical resection as a part of multimodality treatment improves survival in carefully selected locally advanced gallbladder cancer patients with jaundice. Early introduction of systemic therapy is the key in the management of this disease with aggressive tumor biology.

Do palliative embolization in unresectable, unsalvageable recurrent and metastatic head and neck cancer patients help?

BACKGROUND: Bleeding from the unsalvageable recurrent and metastatic head and neck cancer is not an uncommon occurrence. It is extremely distressing for the patients and their family members and also to the treating doctors. One of the ways to manage this crisis is by selective embolization of the bleeding vessel. METHODOLOGY: In this retrospective study, we audited the patients with unresectable, unsalvageable recurrent and/or metastatic head and neck cancer who underwent selective (palliative) embolization for bleeding at our institute between Jan 2015 and Nov 2019, and assessed its possible benefit in terms of bleeding free interval achieved. RESULTS: Twenty-six palliative embolization was done during the above mentioned period. The majority were male patients (n = 23, 88.4%) with a median age of 54.5 years. The performance status (PS) of most patients was 2 (n = 15, 57.6%). The most common bleeding vessel was the external carotid artery or one of its branches, most commonly lingual artery (n = 5). The bleeding vessel was identified and embolized with PVA/gel foam/coil/glue. All the procedures were uneventful. Out of 26 patients, 3 patients had another bleeding episode subsequently. Most patients had 20 days to 21 months of bleeding free interval. The cost involved in the procedure was between 400 and 2100 US dollars. CONCLUSIONS: Selective embolization is an option to be considered in certain patients with unresectable, unsalvageable recurrent and/or metastatic head and neck cancer, when they present with sudden and massive bleeding to the emergency department, at centres where the facility and expertise for this procedure might be available.

Interventional Radiology in Obstetric Emergencies.

Postpartum hemorrhage (PPH) is one of the common causes of morbidity as well as mortality among pregnant women. Obstetric hemorrhage embolization (OHE)/uterine artery embolization (UAE) is the preferred treatment for PPH which has failed medical therapy. In cases of placental accreta spectrum (PAS), balloon catheter can be prophylactically placed in internal iliac arteries (IIAs) bilaterally before delivery to enable postpartum control of bleeding. An inferior vena cava (IVC) filter can be placed under fluoroscopy for a pregnant woman with deep vein thrombosis (DVT) for whom anticoagulation is contraindicated or needs to be stopped at the time of labor. Injection of chemical into the gestational sac can be performed under ultrasonography (USG) guidance to treat ectopic pregnancy. Percutaneous or transvaginal drainage of a collection can be done by ultrasound or computed tomography (CT) guidance for puerperal sepsis. Percutaneous nephrostomy (PCN) is performed for obstructive ureterolithiasis in case of urosepsis or significant stone burden. Sonography should be used for the guidance of interventional radiology (IR) procedures whenever possible. Fluoroscopy must be used only if necessary, giving special attention to radiation-sparing maneuvers. How to cite this article: Kulkarni S, Shetty NS, Gupta A, Rao S, Bansal H. Interventional Radiology in Obstetric Emergencies. Indian J Crit Care Med 2021;25(Suppl 3):S273-S278.

Indian Council of Medical Research consensus document on hepatocellular carcinoma.

This document aims to assist oncologists in making clinical decisions encountered while managing their patients with hepatocellular carcinoma (HCC), specific to Indian practice, based on consensus among experts. Most patients are staged by Barcelona Clinic Liver Cancer (BCLC) staging system which comprises patient performance status, Child-Pugh status, number and size of nodules, portal vein invasion and metastasis. Patients should receive multidisciplinary care. Surgical resection and transplant forms the mainstay of curative treatment. Ablative techniques are used for small tumours (<3 cm) in patients who are not candidates for surgical resection (Child B and C). Patients with advanced (HCC should be assessed on an individual basis to determine whether targeted therapy, interventional radiology procedures or best supportive care should be provided. In advanced HCC, immunotherapy, newer targeted therapies and modern radiation therapy have shown promising results. Patients should be offered regular surveillance after completion of curative resection or treatment of advanced disease.

Liver resection for HCC outside the BCLC criteria.

PURPOSE: Surgical resection still remains the mainstay of management of hepatocellular carcinoma (HCC). At present, Barcelona clinic liver cancer (BCLC) staging is the most widely used tool to guide treatment; however, criteria for offering surgery as curative treatment are restrictive. We aimed to evaluate short-term and long-term outcomes of HCC after resection, even for patients outside BCLC criteria for resection. METHODS: Data was collected from a prospective database from GI and HPB Department, Tata Memorial Hospital, Mumbai. Study period was from June 2010 to June 2015. RESULTS: One hundred three patients of HCC were operated during this period, of which 100 underwent complete resection. Patients were staged according to the BCLC classification (BCLC stage A-25, B-64, C-11). Preoperative therapy was administered in 36 (36%) patients. At median follow-up of 21 months, overall 3-year survival for BCLC stages A, B, and C was 55.2, 62.7, and 37.5%, respectively. CONCLUSION: In today's era of liver transplantation, resection (especially for larger tumors) may still be the preferred treatment option, considering problems and difficulties in donor availability, cost, and long waiting list for liver transplant. With evolving modern surgical technique, long-term survival benefit can be achieved with acceptable safety in most BCLC stage B and selected BCLC stage C patients and those who either do not fit into the transplant criteria or cannot afford transplant. Carefully designed trials are required to further elucidate these results.

Neoadjuvant chemotherapy in patients with locally advanced gallbladder cancer.

AIM: Surgery is the only curative option for patients with gallbladder cancer (GBC). This study looks at the outcome of patients treated with neoadjuvant chemotherapy (NACT). PATIENTS & METHODS: This is retrospective analysis of the prospectively maintained database of patients with locally advanced GBC treated between February 2009 and September 2013 with NACT. Patients received gemcitabine-platinum based regimen. RESULTS: A total of 37 patients (median age: 54 years, 64.9% females) received NACT. Overall response rate was 67.5%. In total, 17 patients (46%) underwent R0 resection. Median overall survival/progression-free survival of the whole group was 13.4/8.1 months, respectively. Patients who underwent surgery had a significantly better overall survival (median not reached vs 9.5 months) and progression-free survival (25.8 vs 5.6 months), respectively. CONCLUSION: NACT increases resectability and survival in patients with locally advanced GBC.

Use of gemcitabine-platinum in Indian patients with advanced gall bladder cancer.

BACKGROUND: Gemcitabine-platinum (Gem-P) is the current standard for patients with advanced gall bladder cancer. MATERIALS & METHODS: This is retrospective analysis of a prospectively maintained database of 210 patients with advanced gall bladder cancer treated with Gem-P between January 2012 and September 2013. RESULTS: Median age was 53 years, 65.2% females. In total,158 patients had metastatic and 52 had locoregional disease. Median number of cycles was 5 (1-12). At a median follow-up of 10 months, median overall survival/progression-free survival was 10/5 months, respectively. On multivariate analysis, patients who underwent prior surgery for primary and locoregional disease had a significantly better progression-free survival and those with locoregional disease had a significantly better overall survival. A total of 45.7% received second-line chemotherapy. CONCLUSION: Use of Gem-P in Indian patients leads to slightly worse outcomes suggesting an aggressive biology.

The role of squash cytology in rapid on-site adequacy checking and rapid diagnosis in image-guided gun biopsy at a tertiary cancer center.

OBJECTIVE: To evaluate the role of squash cytology in rapid on-site adequacy checking (ROSAC) of image-guided gun biopsy and to determine its diagnostic accuracy at a tertiary cancer center. STUDY DESIGN: This was a prospective study on 183 patients undergoing image-guided biopsy. Squash smears were prepared from biopsy cores and checked for adequacy by cytotechnologists. When adequate, more cores were sampled from the same area for histopathology. If inadequate, the procedure was repeated at the same sitting on a different area. The squash smears were reported by cytopathologists within 4 h after staining with conventional Papanicoloau stain. The results were compared with the final histopathology report. RESULTS: The sampling was representative in 95.6% cases with concordance for adequacy in 97.3% cases. The sensitivity, specificity, positive predictive value and negative predictive value of squash cytology for diagnosis of the lesion were 99.4, 92.7, 97.7 and 97.4%, respectively. CONCLUSIONS: Squash cytology is an ideal and cost-effective technique for ROSAC of image-guided biopsies, which ensures adequacy, avoids repeat procedures and prevents delay in diagnosis. It can be effectively performed by trained cytotechnologists in radiology clinics. Squash cytology is also a cost-effective tool offering rapid diagnosis which expedites planning of treatment.

Impact of post-hepatectomy biliary leaks on long-term survival in different liver tumors: A single institute experience.

Backgrounds/Aims: A postoperative biliary leak is one of the most morbid complications occurring after a liver resection, the long-term impact of which remains unknown. Methods: Retrospective analysis of consecutive liver resections performed from 1 January 2011 to 31 December 2021. Primary endpoint of disease-free survival (DFS) was compared between patients with and without a bile leak, stratifying for tumor type. Survival curves were plotted using Kaplan-Meier estimates, and differences between them were analyzed using the log-rank test. Results: In toto, 862 patients were analyzed, and included 306 (35.5%) hepatocellular carcinomas, 212 (24.6%) metastatic colorectal cancers, and 111 (12.9%) cholangiocarcinomas (69 intrahepatic cholangiocarcinomas, 42 hilar cholangiocarcinomas). Occurrence of a bile leak was associated with significantly poorer DFS only in patients with cholangiocarcinoma (median DFS 9.9 months vs. 24.9 months, p = 0.013), and further analysis was restricted to this cohort. A Cox regression performed for factors associated with DFS detriment in patients with cholangiocarcinoma showed that apart from node positivity (hazard ratio [HR]: 2.482, p = 0.033) and margin positivity (HR: 2.65, p = 0.021), development of a bile leak was independently associated with worsening DFS on both univariate and multiple regression analyses (HR: 1.896, p = 0.033). Conclusions: Post-hepatectomy biliary leaks are associated with significantly poorer DFS only in patients with cholangiocarcinoma, but not in patients with hepatocellular carcinoma or metastatic colorectal cancer. Methods to mitigate this survival detriment need to be explored.

Epidemiology, Diagnosis and Genetics of Retinoblastoma: ICMR Consensus Guidelines.

Retinoblastoma (RB) is the most common intraocular tumor in childhood. It is mainly caused by mutations in both alleles of the RB1 tumor suppressor gene that is found on chromosome 13 and regulates the cell cycle. Approximately 8000 children are diagnosed with RB globally each year, with an estimated 1500 cases occurring in India. The survival rate of RB has improved to more than 90% in the developed world. Leukocoria and proptosis are the most common presenting features of RB in Asian Indian populations. Most cases of RB are diagnosed by fundus examination followed by ultrasound. The International Classification of Retinoblastoma is the most used scheme for the staging and classification of intraocular RB in India. Prenatal testing and preimplantation genetic testing for RB may be beneficial in high-risk families. Histopathologic risk factors such as massive choroidal invasion and post-laminar optic nerve help in predicting the occurrence of metastasis in children with RB, while presence of microscopic residual disease requires aggressive adjuvant treatment in eyes enucleated for group E RB. The review provides a consensus document on diagnosis and genetics of RB in India.

[90Y]Yttria Alumino Silicate Glass Microspheres: A Biosimilar Formulation to "TheraSphere" for Cost-Effective Treatment of Liver Cancer.

Background: Selective internal radiation therapy (SIRT) using a suitable ß--emitting radionuclide is a promising treatment modality for unresectable liver carcinoma. Yttrium-90 (90Y) [T1/2 = 64.2 h, Eß(max) = 2.28 MeV, no detectable γ-photon] is the most preferred radioisotope for SIRT owing to its favorable decay characteristics. Objective: The present study describes indigenous development and evaluation of intrinsically radiolabeled [90Y]yttria alumino silicate ([90Y]YAS) glass microsphere, a formulation biosimilar to "TheraSphere" (commercially available, U.S. FDA-approved formulation), for SIRT of unresectable liver carcinoma in human patients. Methods: YAS glass microspheres of composition 40Y2O3-20Al2O3-40SiO2 (w/w) and diameter ranging between 20 and 36 µm were synthesized with almost 100% conversion efficiency and >99% sphericity. Intrinsically labeled [90Y]YAS glass microspheres were produced by thermal neutron irradiation of cold YAS glass microspheres in a research reactor. Subsequent to in vitro evaluations and in vivo studies in healthy Wistar rats, customized doses of [90Y]YAS glass microspheres were administered in human patients. Results: [90Y]YAS glass microspheres were produced with 137.7 ± 8.6 MBq/mg YAS glass (∼6800 Bq per microsphere) specific activity and 99.94% ± 0.02% radionuclidic purity at the end of irradiation. The formulation exhibited excellent in vitro stability in human serum and showed >97% retention in the liver up to 7 d post-administration when biodistribution studies were carried out in healthy Wistar rats. Yttrium-90 positron emission tomography scans recorded at different time points post-administration of customized dose of [90Y]YAS glass microspheres in human patients showed near-quantitative retention of the formulation in the injected lobe. Conclusions: The study confirmed the suitability of indigenously prepared [90Y]YAS glass microspheres for clinical use in the treatment of unresectable hepatocellular carcinoma.

Management of Intraocular Retinoblastoma: ICMR Consensus Guidelines.

Retinoblastoma (RB) is the most common childhood intraocular malignancy. Delayed presentation due to a lack of awareness and advanced intraocular tumors are a common scenario in low-middle income countries (LMICs). Remarkable treatment advances have been made in the past few decades allowing globe salvage in advanced intraocular RB (IORB) including systemic chemotherapy with focal consolidation and targeted treatments like intraarterial chemotherapy and intravitreal chemotherapy. However, a lack of availability and affordability limits the use of such advances in LMICs. External beam radiotherapy, despite risk of second cancers in RB with germline mutations, still remains useful for recalcitrant RB not responding to any other treatment. When choosing conservative treatment for advanced IORB, the cost and long duration of treatment, morbidity from multiple evaluation under anesthesias (EUAs), side effects of treatment and risk of treatment failure need to be taken into account and discussed with the parents. In this article, the authors discuss the ICMR consensus guidelines on the management of IORB.

Evaluation of an Objective MRI-Based Tumor Regression Grade (mrTRG) Score and a Subjective Likert Score for Assessing Treatment Response in Locally Advanced Rectal Cancers-A Retrospective Study.

Purpose: Magnetic resonance imaging (MRI) with the help of MRI-based tumor regression grade (mrTRG) score has been used as a tool to predict pathological tumor regression grade (pTRG) in patients of rectal cancer post-neoadjuvant chemoradiation. Our study aims to evaluate the ability of MRI in assessing treatment response comparing an objective mrTRG score and a subjective Likert score, with a focus on the ability to predict pathologic complete response (pCR). Methods: Post-treatment MRI studies were retrospectively reviewed for 170 consecutive cases of histopathologically proven rectal cancer after receiving neoadjuvant chemoradiation and prior to surgery by two oncoradiologists blinded to the eventual postoperative histopathology findings. An objective (mrTRG) and a subjective Likert score were assigned to all the cases. Receiver operating characteristic curves were constructed to determine the ability of Likert scale and mrTRG to predict pCR, with postoperative histopathology being the gold standard. The optimal cutoff points on the scale of 1 to 5 were obtained for mrTRG and Likert scale with the greatest sum of sensitivity and specificity using the Youden Index. Results: The most accurate cutoff point for the mrTRG to predict complete response was 2.5 (using Youden index), with a sensitivity of 69.2%, specificity of 69.6%, positive predictive value (PPV) of 85.6%, negative predictive value (NPV) of 46.4%, and accuracy of 69.3%. The most accurate cutoff for the Likert scale to predict complete response was 3.5, with a sensitivity of 47.5%, specificity of 89.1%, PPV of 91.9%, NPV of 39.4%, and accuracy of 59%. mrTRG had a lower cutoff and was more accurate in predicting pCR compared to Likert score. Conclusion: An objective mrTRG was more accurate than a subjective Likert scale to predict complete response in our study.