Avoiding Unnecessary Major Rectal Cancer Surgery by Implementing Structural Restaging and a Watch-and-Wait Strategy After Neoadjuvant Radiochemotherapy.

BACKGROUND: Pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) is found in 15-20% of patients with locally advanced rectal cancer. A watch-and-wait (W&W) strategy has been introduced as an alternative strategy to avoid surgery for selected patients with a clinical complete response at multidisciplinary response evaluation. The primary aim of this study was to evaluate the efficacy of the multidisciplinary response evaluation by comparing the proportion of patients with pCR since the introduction of the structural response evaluation with the period before response evaluation. METHODS: This retrospective cohort study enrolled patients with locally advanced rectal cancer who underwent nCRT between January 2009 and May 2018, categorizing them into cohort A (period 2009-2015) and cohort B (period 2015-2018). The patients in cohort B underwent structural multidisciplinary response evaluation with the option of the W&W strategy. Proportion of pCR (ypT0N0), time-to-event (pCR) analysis, and stoma-free survival were evaluated in both cohorts. RESULTS: Of the 259 patients in the study, 21 (18.4%) in cohort A and in 8 (8.7%) in cohort B had pCR (p = 0.043). Time-to-event analysis demonstrated a significant pCR decline in cohort B (p < 0.001). The stoma-free patient rate was 24% higher in cohort B (p < 0.001). CONCLUSION: Multidisciplinary clinical response evaluation after nCRT for locally advanced rectal cancer led to a significant decrease in unnecessary surgery for the patients with a complete response.

MRI cT1-2 rectal cancer staging accuracy: a population-based study.

BACKGROUND: Adequate MRI-based staging of early rectal cancers is essential for decision-making in an era of organ-conserving treatment approaches. The aim of this population-based study was to determine the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography (ERUS). METHODS: Patients with cT1-2 rectal cancer who underwent local excision or total mesorectal excision (TME) without downsizing (chemo)radiotherapy between 1 January 2011 and 31 December 2018 were selected from the Dutch ColoRectal Audit. The accuracy of imaging was expressed as sensitivity, specificity, and positive predictive value (PPV) and negative predictive value. RESULTS: Of 7382 registered patients with cT1-2 rectal cancer, 5539 were included (5288 MRI alone, 251 MRI and ERUS; 1059 cT1 and 4480 cT2). Among patients with pT1 tumours, 54·7 per cent (792 of 1448) were overstaged by MRI alone, and 31·0 per cent (36 of 116) by MRI and ERUS. Understaging of pT2 disease occurred in 8·2 per cent (197 of 2388) and 27·9 per cent (31 of 111) respectively. MRI alone overstaged pN0 in 17·3 per cent (570 of 3303) and the PPV for assignment of cN0 category was 76·3 per cent (2733 of 3583). Of 834 patients with pT1 N0 disease, potentially suitable for local excision, tumours in 253 patients (30·3 per cent) were staged correctly as cT1 N0, whereas 484 (58·0 per cent) and 97 (11·6 per cent) were overstaged as cT2 N0 and cT1-2 N1 respectively. CONCLUSION: This Dutch population-based analysis of patients who underwent local excision or TME surgery for cT1-2 rectal cancer based on preoperative MRI staging revealed substantial overstaging, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.

ANTECEDENTES: Una adecuada estadificación mediante resonancia magnética nuclear (RMN) de los cánceres de recto en estadios precoces es esencial para la toma de decisiones en una era en la existen diferentes opciones de tratamiento preservadoras del recto. El objetivo de este estudio de base poblacional fue determinar la precisión de la estadificación mediante RMN del cáncer de recto precoz en la práctica diaria, ya sea combinada o no con la ecografía endorectal (endorectal ultrasound, ERUS). MÉTODOS: Los pacientes con cáncer de recto en estadio cT1-2 que se sometieron a resección local o resección total del mesorrecto (total mesorectal excision, TME) sin (quimio) radioterapia neoadyuvante fueron seleccionados a partir del registro auditado ColoRectal holandés, entre el 1 de enero de 2011 y el 31 de diciembre de 2018. La precisión de las imágenes se expresó como sensibilidad, especificidad y valores predictivos positivo y negativo (positive- and negative predicting value, PPV / NPV). RESULTADOS: De un total de 7.382 pacientes registrados con cáncer de recto en estadio cT1-2, se incluyeron 5.539 pacientes (5.288 solamente RMN, 251 RMN + ERUS; 1.059 cT1 y 4.480 cT2). Los pacientes pT1 fueron sobreestadificados cuando se utilizó únicamente la RMN en un 54,7% de los casos (792/1.448) y cuando se combinó RMN y ERUS en un 31,0% (36/116). La infraestadificación de pT2 ocurrió en un 8,2% (197/2.388) y en un 27,9% (31/111), respectivamente. La RMN utilizada como única prueba sobreestadificó los casos pN0 en el 17,3% (570/3.303) y el VPP del estadio cN0 fue del 76,3% (2.733/3.583). De los 834 pacientes con estadio pT1N0, potencialmente adecuado para la resección local, 253 pacientes (30,3%) se clasificaron correctamente como cT1N0, y 484 (58,8%) y 97 (11,6%) pacientes se sobreestadificaron como cT2N0 y cT1-2N1, respectivamente. CONCLUSIÓN: Este estudio de base poblacional holandés en pacientes que se sometieron a una resección local o a cirugía TME por cáncer de recto cT1-2 con estadificación preoperatoria mediante RMN, muestra una considerable sobreestadificación, lo que indica las debilidades y oportunidades en las estrategias de preservación del recto.

Population-based study of morbidity risk associated with pathological complete response after chemoradiotherapy for rectal cancer.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer may induce a pathological complete response (pCR) but increase surgical morbidity due to radiation-induced fibrosis. In this study the association between pCR and postoperative surgical morbidity was investigated. METHODS: Patients in the Netherlands with rectal cancer who underwent nCRT followed by total mesorectal excision between 2009 and 2017 were included. Data were stratified into patients who underwent resection with creation of a primary anastomosis and those who had a permanent stoma procedure. The association between pCR and postoperative morbidity was investigated in univariable and multivariable logistic regression analyses. RESULTS: pCR was observed in 976 (12·2 per cent) of 8003 patients. In 3472 patients who had a primary anastomosis, the presence of pCR was significantly associated with surgical complications (122 of 443 (27·5 per cent) versus 598 of 3029 (19·7 per cent) in those without pCR) and anastomotic leak (35 of 443 (7·9 per cent) versus 173 of 3029 (5·7 per cent) respectively). Multivariable analysis also showed associations between pCR and surgical complications (adjusted odds ratio (OR) 1·53, 95 per cent c.i. 1·22 to 1·92) and pCR and anastomotic leak (adjusted OR 1·41, 1·03 to 2·05). Of 4531 patients with a permanent stoma, surgical complications were observed in 120 (22·5 per cent) of 533 patients with a pCR, compared with 798 (20·0 per cent) of 3998 patients with no pCR (adjusted OR 1·17, 0·94 to 1·46). CONCLUSION: Patients with a pCR in whom an anastomosis was created were at increased risk of developing an anastomotic leak.

ANTECEDENTES: La quimiorradioterapia neoadyuvante (neoadjuvant chemoradiotherapy, nCRT) para el cáncer de recto localmente avanzado puede inducir una respuesta patológica completa (pathological complete response, pCR), pero también puede aumentar la morbilidad quirúrgica debido a la fibrosis inducida por la radiación. En este estudio se investigó la asociación entre pCR y morbilidad quirúrgica postoperatoria. MÉTODOS: Se incluyeron los pacientes con cáncer de recto que recibieron nCRT seguida de resección total del mesorrecto entre 2009 y 2017 en los Países Bajos. Los datos se estratificaron en pacientes en los que se realizó una resección con anastomosis primaria y en los que se realizó una resección con estoma permanente. La asociación entre pCR y morbilidad postoperatoria se investigó mediante análisis de regresión logística univariable y multivariable. RESULTADOS: Se observó una pCR en 976 (12,2%) de 8.003 pacientes. En el grupo de pacientes con anastomosis primaria (n = 3472), la presencia de pCR se asoció significativamente con complicaciones quirúrgicas (n = 122; 27,5% versus n = 598; 19,7% sin pCR) y fuga anastomótica (n = 35; 7,9 % versus n = 173; 5,7% sin pCR). Las asociaciones entre la pCR y las complicaciones quirúrgicas y la pCR y la fuga anastomótica también se confirmaron en los análisis multivariables (razón de oportunidades ajustada, odds ratio, OR ajustado: 1,53; i.c. del 95%: 1,22-1,92; OR ajustado: 1,41; i.c. del 95%: 1,03-2,05, respectivamente). En el grupo con estoma permanente (n = 4.531), se observaron complicaciones quirúrgicas en 120 pacientes (22,5%) en los casos con presencia de pCR en comparación con 798 pacientes (20%) en ausencia de pCR (OR ajustado: 1,17; i.c. del 95%: 0,94-1,46). CONCLUSIÓN: Los pacientes con pCR en los que se realizó una anastomosis tenían mayor riesgo de presentar una fuga anastomótica.

2D radially compensating excitation pulse in combination with an internal transceiver antenna for 3D MRI of the rectum at 7 T.

PURPOSE: The high precession frequency in ultrahigh field MRI coincides with reduced RF penetration, increased RF power deposition and consequently can lead to reduced scan efficiency. However, the shorter wavelength enables the use of efficient antennas rather than loop coils. In fact, ultrathin monopole antennas have been demonstrated at 7 T, which fit in natural cavities like the rectum in the human body. As the RF field generated by the antenna provides an extremely nonuniform B1 field, the use of conventional RF pulses will lead to severe image distortions and highly nonuniform contrast. However, using the two predominant dimensions (orthogonal to the antenna), 2D RF pulses can be designed that counteract the nonuniform B1 into uniform flip angles. In this study the authors investigate the use of an ultrathin antenna not only for reception, but also for transmission in 7 T MRI of the rectum. METHODS: The 2D radially compensating excitation (2D RACE) pulse was designed in matlab. SAR calculations between the 2D RACE pulse and an adiabatic RF pulse (BIR-4) have been obtained, to visualize the gain in decreasing the SAR when using the 2D RACE pulse instead of an adiabatic RF pulse. The authors used the 7 T whole body MR system in combination with an internally placed monopole antenna used for transceiving and obtained 3D gradient echo images with a conventional sinc pulse and with the 2D RACE pulse. For extra clarity, they also reconstructed an image where the receive field of the antenna was removed. RESULTS: Comparing the results of the SAR simulations of the 2D RACE pulse with a BIR-4 pulse shows that for low flip angles (θ < 41°) the SAR can be decreased with a factor of 4.8 or even more, when using the 2D RACE pulse. Relative to a conventional sinc excitation, the 2D RACE pulse achieves more uniform flip angle distributions than a BIR-4 pulse with a smaller SAR increase (16 × versus 64 ×). CONCLUSIONS: The authors have shown that the 2D RACE pulse provides more homogeneous flip angles for gradient echo sequences when compared to a conventional sinc pulse albeit at increased SAR. However, when compared to adiabatic RF pulses, as shown by simulations, the SAR of the 2D RACE pulse can be an order of magnitude less. Phantom and in vivo human rectum images are obtained to demonstrate that the 2D RACE pulse can provide a uniform excitation while transmitting with a single ultrathin endorectal antenna at 7 T. The combination of thin rectal antennas with efficient uniform transmit can open up new possibilities in high resolution imaging of rectal cancer.

Imaging of oesophageal cancer with FDG-PET/CT and MRI.

Integrated 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) PET/CT and magnetic resonance imaging (MRI) with functional features of diffusion-weighted imaging (DWI) are advancing imaging technologies that have current and future potential to overcome important limitations of conventional staging methods in the management of patients with oesophageal cancer. PET/CT has emerged as an important part of the standard work-up of patients with oesophageal cancer. Besides its important ability to detect unsuspected metastatic disease, PET/CT may be useful in the assessment of treatment response, radiation treatment planning, and detection of recurrent disease. In addition, high-resolution T2-weighted MRI and DWI have potential complementary roles. Recent improvements in MRI protocols and techniques have resulted in better imaging quality with the potential to bring improvement in staging, radiation treatment planning, and the assessment of treatment response. Optimal use and understanding of PET/CT and MRI in oesophageal cancer will contribute to the impact of these advancing technologies in tailoring treatment to the individual patient and achieving best possible outcomes. In this article, we graphically outline the current and potential future roles of PET/CT and MRI in the multidisciplinary management of oesophageal cancer.

Diffusion-weighted MRI in locally advanced rectal cancer : pathological response prediction after neo-adjuvant radiochemotherapy.

BACKGROUND AND PURPOSE: The aim of this study was to assess the predictive potential of diffusion-weighted magnetic resonance imaging (MRI) for the selection of favorable pathological responders after radiochemotherapy for locally advanced rectal cancer. PATIENTS AND METHODS: In 59 patients with locally advanced rectal cancer, the apparent diffusion coefficient (ADC) in the tumor was obtained at 3 Tesla before radiochemotherapy and surgery. The predictive potential for pathological complete response (pCR) and good response (GR) was assessed. GR was defined as pCR and near-pCR based on the tumor regression grade. RESULTS: The GR group consisted of 13 patients (22%) with 9 complete responders. Both the preradiochemotherapy ADC values and relative change in ADC (ΔADC) were predictive for pathological response. Preradiochemotherapy ADC values showed a positive predictive value of 42% for pCR and 67% for GR using a similar cut-off value of 0.97(*)10(-3) mm(2)/s. For ΔADC, the optimal threshold for predicting GR or pCR was a 41% increase of the ADC. With this threshold, positive predictive values of 64% and 91% were found for pCR and GR, respectively. CONCLUSION: Low preradiochemotherapy ADC values and high ΔADC correspond to pathological good response. Diffusion-weighted MRI may be used as an additional tool for selecting good treatment responders after radiochemotherapy.

SU-E-J-57: MRI-Linac (MRL) Guided Treatment for Esophageal Cancer.

For radiotherapy, oesophageal cancer is located in a difficult area. Spatial control of the dose distribution is difficult to achieve with current CT-based radiation techniques, as on CT, soft-tissue contrast is too low. Furthermore, the oesophagus moves and organs at risk (e.g. lung, heart, liver, spinal cord) are in close proximity. An 1.5 T MRI-accelerator (MRL) has sufficient soft-tissue tumour visualization possibilities to allow for precise real-time, online, position verification and for dose escalation without organ at riskoverdose. Our research consists of the preparatory work for the first clinical study on the MRL for patients with oesophageal cancer. To improve image quality and reduce the motion artefacts, the benefit of cardiac triggering and breath holds is evaluated on fifteen oesophageal patients. Results show the superb image quality of these MRI sequences. The use of this high quality MRI gives the possibility for non-invasive real-time visualization andtracking of the tumour. We quantify oesophageal tumour motion on cineMRI. The tumour is tracked on sequential mixed T1/T2w images (acquisition time: 60s, temporal resolution: 0.5s, slice thickness: 7mm) of a single coronal and sagittal slice using a Minimum Output Sum of Squared Error (MOSSE) adaptive correlation filter. Tumour registration within the individual images can typically be done at a millisecond time scale. Motion of oesophageal tumours can well be tracked and is highly variable between patients. The greatest mobility is seen in cranio-caudal direction, with amaximum peak-to-peak amplitude of tumour movement of 24.5mm followed by the dorso-ventral and the medio-lateral direction. Movement seems greatest in tumours located in the lower part of the oesophagus. This study shows both the superb image quality for GTV localisation and the possibility for on-line and real time tumour tracking. The study opens thepossibility for tracked radiation delivery with a 1.5T MRI accelerator. Partial funding has been obtained by Elekta and Philips.

Developments in treatment of primary irresectable rectal cancer.

Abstract The treatment options for primary irresectable rectal cancers are discussed. Assessment of tumour stage is the first step for an appropriate choice of treatment. Following a diagnosis of rectal cancer, a vast array of diagnostic procedures is available to determine its stage, and thereby its best treatment options. From the many (new) diagnostic options the merits and drawbacks are discussed. If a diagnosis of irresectability is made, further treatment options should include radiotherapy in most cases, some aspects of timing and application, i.e. intra-operative treatment are discussed. Chemotherapy options are manifold, the results are discussed and some new options are explored.

Treatment of locally recurrent rectal cancer, results and prognostic factors.

PURPOSE: Assessment of the results and prognostic factors in patients with locally recurrent rectal cancer treated with curative intent. PATIENTS AND METHODS: Forty patients with an isolated pelvic recurrence of rectal cancer were studied retrospectively. The treatment consisted of radiotherapy alone or combined with chemotherapy and/or surgery performed between January 1992 and July 2001. Radiotherapy was given with a 3-4 fields technique (6-15 MV), five times a week. The median radiation dose was 50 Gy (range 25-66.6 Gy). Twenty-five patients underwent salvage surgery. Five patients were treated with concomitant chemotherapy (5-fluoro-uracil/leucovorin) (5FU/LV) during the 1st and 5th week of radiotherapy. RESULTS: Twenty-two of the 40 patients were male. The local recurrence free survival after 3 and 5 years, respectively, was 49 and 39%. Male gender was the only independent factor associated with failure of local control. The 3 and 5-year overall survival of the total group was 36 and 19%, respectively, with a median survival of 26 months. CONCLUSION: In a selection of patients in the treatment of locally recurrent rectal cancer valuable local palliation if not cure, can be reached. A multimodality approach seems to offer the best chances in this threatening situation.

5FU and oxaliplatin-containing chemotherapy in two dihydropyrimidine dehydrogenase-deficient patients.

Patients with a germline mutation leading to a deficiency of the dihydropyrimidine dehydrogenase (DPD) enzyme are at risk from developing severe toxicity on the administration of 5FU-containing chemotherapy. We report on the implications of this inborn genetic error in two patients who received 5FU and oxaliplatin. A possible co-medication effect of oxaliplatin is considered, as are the consequences of screening for DPD deficiency.

A favourable pathological stage after neoadjuvant radiochemotherapy in patients with initially irresectable rectal cancer correlates with a favourable prognosis.

Initial treatments of locally advanced rectal cancers focus on local control, as local relapse of a rectal cancer is correlated with a high morbidity and mortality. We studied the effect of neoadjuvant radiochemotherapy on advanced rectal cancer patients in relation to downstaging, local relapse and survival. Post-treatment pathological staging, local relapse and survival were analysed in 66 patients from a single institution. 43 patients had irresectable cancer as determined by laparatomy (n=42) or rectal examination (n=1). These 43 patients received 45-56 Gy preoperatively with 5-fluorouracil (5-FU) and leucovorin (350/20 mg/m(2)x5 day (d)) in weeks 1 and 5 during the radiation therapy. 23 patients had primary resectable tumours with a T1-2 stage. Of the initially irresectable tumours 79% became macroscopically resectable, in 74% a R0 resection was performed. In 6 of 34 (18%) surgical specimens, no tumour was found (pT0), 7 patients had small tumour remnants (pT1-2). In these pT0-2 tumours, no local relapses occurred (observation period of median 4.5 years, range 18-87 months). In the 21 patients with pT3-4 tumours 3 local relapses were seen. In the 23 patients with primary resectable T1-2 tumours the relapse rate was 4%. Downstaging of an initially irresectable rectal tumour to pT2 or less results in a local relapse rate and overall survival that correspond with the rates in primary resectable cancer with the same T classification.

[Laparoscopic pelvic lymph node dissection for clinical staging of prostate cancer: encouraging preliminary results]. / Laparoscopische bekkenklierdissectie voor klinische stadiëring bij prostaatcarcinoom: gunstige eerste ervaringen.

OBJECTIVE: To evaluate the results of the first 72 laparoscopic pelvic lymph node dissections in patients with prostate cancer. DESIGN: Retrospective study of records. SETTING: Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands. METHOD: A retrospective study of records provided data on 72 patients with prostate cancer staged by laparoscopic lymph node dissection in the period 1993-1997. Per- and postoperative complications, operation time, number of removed lymph nodes, pathology result and duration of hospital stay were assessed. A comparison was made between the first series of 36 patients and the second series. RESULTS: In 9 patients the laparoscopic approach was converted to a laparotomy. This occurred six times in the first series of 36 patients and three times in the second series. The postoperative course was complicated six times in the first and four times in the second series. With increasing experience the mean operation time decreased from 140 min to 114 min in the second series (p < 0.0001). The mean number of nodes removed was equal in both series (7.5). Lymph node metastases were found in 20 patients (28%). Hospital stay was 2.9 days in the first series and 2.2 days in the second series (not significant). CONCLUSION: Laparoscopic pelvic lymph node dissection is a minimally invasive method for staging patients with prostate cancer. This staging procedure is of great benefit in patients scheduled for treatment with curative intent because of its accuracy and low morbidity. With increasing experience operation time, hospital stay and number of complications decrease.