RU2547686C2 - Diagnostic technique for small pelvis tumours - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly to diagnostics. A method involves placing the patient and defining the range of interest for a percutaneous needle biopsy followed by sampling and analysing a histological material. A magnetic resonance tomography is followed by determining the parameters of biopsy needle insertion, including potential injuries of vital organs, vascular and neural structures. A needle insertion point is defined on a traverse line marked on the patient's skin and topically corresponding to the range of interest taking into account a placed fatty capsule. A needle insertion angle is specified according to an angle between a vertical line passing through the centre of the range of interest, and a line connecting the biopsy needle insertion point and the centre of the range of interest. Required needle penetration and inclination are controlled.

EFFECT: method prevents organ injuries by increasing the biopsy needle insertion accuracy.

2 tbl, 11 dwg, 4 ex

Description

The invention relates to medicine, in particular to oncology using nuclear magnetic resonance (NMR) for imaging, using biopsy sampling tools and their subsequent study.

The complex anatomical location of organs and vessels in the pelvic area creates problems when performing interventions under radiological and ultrasound control (Wells PN Ultrasound imaging // Phys Med Biol, 2006, 51: R83-R98; Feuerbach S., Schreyer A., Schlottmann K Standards in radiographically guided biopsies -indications, techniques, complications // Radiologic Up2date, 2003, 3: 207-223; Haaga JR Interventional CT: 30 years' experience // Eur Radiol, 2005, 15 (Suppl 4): D116-D120 ) The absence of radiation exposure, the high contrast of soft tissues and the ability to obtain images in any plane make magnetic resonance imaging an ideal way to control when performing interventional intervention (Lamb GM, Gedroyc WM Interventional magnetic resonance imaging // Br J Radiol, 1997, 70: S81-S88 ) The possibilities of using magnetic resonance imaging when performing invasive diagnostic procedures in the small pelvis are described (Barentsz JO MR intervention in the pelvis: an overview and first experiences in MR-guided biopsy in nodal metastases in urinary bladder cancer // Abdom Imaging, 1997, 22: 524-530). However, despite the high efficiency of this direction, the use of magnetic resonance imaging in interventional radiology is limited by its low prevalence and technical complexity of the method (Lamb G.M., Gedroyc W.M. Interventional magnetic resonance imaging // Br J Radiol, 1997, 70: S81-S88).

A known method of obtaining biopsy material for the diagnosis of local cancer recurrence after radical prostatectomy (RF Patent No. 2471427), including sampling the material using a biopsy needle under the control of transrectal ultrasound. Previously, an urethral catheter is inserted into the urethra, which is visualized and used as a guide when performing injections of a biopsy needle. Twelve samples are taken from the zones of the prostatic bed proper adjacent to the urethra, in a certain sequence. At first, two samples are taken from the neck of the bladder on each side of the catheter relative to the catheter, then one sample from the area of the vesicourethral anastomosis on each side of the urethra, one sample from the projection zones of the neurovascular bundles and one from the external sphincter urethra - two samples.

The disadvantages of the method is the small field of view and localized collection of biopsy material from the bed of the removed prostate gland, which does not allow to detect changes outside the biopsy area, for example, at the wall of the pelvis. In addition, the use of ultrasound examination consists in the "blind" pointing of a biopsy needle to a pre-planned area, and is not based on the differential diagnostic capabilities of the method, which may lead to the taking of biopsy material from areas of benign Scar changes in a priori with a local recurrence.

A known method of puncture aspiration biopsy, involving the percutaneous puncture of focal lesions with puncture needles under ultrasound control (RF Patent No. 2085121), including visual monitoring of the passage of the needle, performing aspiration with a syringe attached to the needle in order to obtain material for research and the possibility of repeated puncture of the focal education.

The disadvantage of this method is the limitation of diagnostic capabilities due to the fact that the resulting material is subjected to cytological rather than histological examination; nearby structures such as bones (ribs) or gas-filled intestines limit the visualization of the target organ, which makes it difficult or impossible to perform a biopsy.

A known method for diagnosing the stage of invasion of bladder cancer (RF Patent No. 2332168) and is intended for tissue biopsy of a tumor of the bladder for subsequent morphological diagnosis of the stage of bladder cancer. The method provides a more reliable establishment of a histological diagnosis and stage of invasion of bladder cancer at the preoperative stage. Histological material is obtained using transrectal ultrasound using an ultrasound transducer with a biopsy attachment mounted on it. An ultrasound probe is inserted into the rectal ampoule and the tumor is visualized on the surface of the bladder wall, then the image of the base of the tumor of the bladder is combined with the image of the biopsy channel formed by the ultrasound probe and the biopsy nozzle. Immerse the biopsy needle in the biopsy channel and strengthen the outer part of the needle in the alignment of the biopsy gun and produce a “shot”. After the shot, a biopsy needle is removed and histological material containing tissue of the wall of the bladder and the base of the tumor is obtained.

The disadvantages of this method is that the method is limited to the location of the tumor and can be effectively performed only in cases where the tumor is located closer to the posterior wall of the bladder, which ensures the optimal location of the biopsy needle and taking the tissue column transverse to the base of the tumor. Also, this method cannot be performed in patients with a removed rectum.

A known method of myometrial biopsy (RF Patent No. 2225169) which is used to assess the condition of the uterus in the scar area after cesarean section. A puncture needle is performed in the area of the postoperative scar on the uterus. At the same time, they retreat from the bosom by 2-3 cm. They pierce the skin, subcutaneous fat, ananeurosis, rectus abdominis, peritoneum, and walls of the filled bladder. Pierce 2/3 of the myometrium in the projection of the scar. Carry out a transabdominal biopsy of the myometrium. The method allows to exclude the introduction of infection from the genital tract, endometrial cells during a myometrial biopsy.

The disadvantages of the method is the restriction of visualization of the uterus with a gas-filled intestine, in addition, there is the possibility of urogenic infection of the uterus when the needle passes through a filled bladder.

The prototype of the proposed technical solution is a method of percutaneous puncture biopsy (RF Patent No. 2362490), which consists in the fact that prior to the biopsy, preliminary assess the localization, size, structure of the focal formation using computed tomography. Then, the optimal puncture points are selected and, using a biopsy needle and a biopsy gun, a puncture biopsy of the focal lesion is performed. In this case, the puncture needle should be no more than 20 cm, with a mandrin diameter equal to the diameter of the biopsy needle, to the border of the focal formation.

After holding the needle to the border of the focal formation, the patient is removed from the aperture of the tomograph, the mandrin is removed from the needle. Using a biopsy gun, the needle is inserted to a depth equal to the length of the mandrel and histological material is collected.

The disadvantage of the prototype is the low tissue contrast when using computed tomography, which makes it limited to use in complex anatomical cases and increases the risk of complications during the introduction of the needle in the area of interest and possible damage to adjacent organs, vascular and neural structures. In addition, the use of computed tomography to control the immersion of the needle increases the radiation load on the patient. It should be noted that bone structures and artifacts from a metal needle can also impede the visualization of the target organ, which makes it difficult to conduct an intervention.

The technical result of the invention is to improve the accuracy of diagnosis of pelvic tumors and reduce the risk of complications during a biopsy.

The previously accumulated experience in the diagnosis of cancer in the pelvic area allows us to draw conclusions about the insufficient effectiveness of the diagnosis of primary and secondary changes, especially in cases of deep location of pathological changes and the inability to perform a biopsy using conventional methods. Such a diagnostic process usually ends with the data of ultrasound, computed and magnetic resonance imaging without obtaining histological material for the necessary verification of the diagnosis. This can lead to a false judgment about the presence or absence of the oncological process, as well as to overstatement or underestimation of its prevalence. Thus, it becomes necessary to further study the revealed pathological changes by obtaining histological material for subsequent morphological studies in order to increase the accuracy of the differential diagnosis of benign and malignant changes. For this, it is necessary to develop a method for accurately guiding the biopsy needle with the best visualization method by eliminating damage to critical organs, vascular and neural structures.

The essence of the proposed technical solution includes patient positioning and centralization of the study area on a magnetic resonance imager in accordance with the desired area of interest for percutaneous puncture biopsy. MR images are obtained in the sagittal and axial planes, along which fat capsules are placed on the patient’s skin and, with respect to them, the biopsy needle is planned for re-acquired MR images. The biopsy needle is phased under MR control immersed to a predetermined depth to the area of interest. Moreover, at each stage, MP images are obtained, which specify the angle of inclination and the penetration lip of the biopsy needle. At the same time, histological material is taken in the necessary areas.

List of figures:

Figure 1. The appearance of the fat capsule.

Figure 2. MP visualization of fat capsule on transverse T2 video

Figure 3. Axial MP image at the lesion level with measurements necessary for planning the introduction of a biopsy needle: A is the distance between the fat capsule and the entry point of the biopsy needle, α is the angle of inclination between the vertical line and the line connecting the entry point of the biopsy needle and the center of the lesion area, B is the distance from skin to the peritoneum / muscle fascia / periosteum, B is the distance from the skin but the beginning of the lesion, G is the distance from the skin to the edge of the lesion.

Figure 4. Biopsy needles for magnetic resonance imaging: 1 - semi-automatic biopsy needle for soft tissues, 2 - aspiration needle, 3 - needle for trepan biopsy.

Figure 5. On the transverse MP tomogram, the boundaries of the infiltrative zone near the right pelvic wall (dashed line) are visualized, involving the large vessels of the small pelvis (eia - external iliac artery, oa - obturator artery, iia - internal iliac artery), sciatic nerve (ni), intestinal loops (I) and uterus (M).

6. On the transverse (6a) and sagittal (6b) MP tomograms during the biopsy, the boundaries of the infiltrative zone of changes (dashed line) and the tip of the conducting needle (arrow) are visualized.

7. On the transverse (7a) and sagittal (7b) MP-tomograms during the biopsy, the cutting part of the semi-automatic biopsy needle is visualized

Fig. 8. Microscopic examination illustrates a fragment of fibrous connective tissue with scattered groups of sharply dystrophic squamous cell cancer cells.

Fig.9. On the transverse (9a) and sagittal (9b) MP tomograms during the biopsy, the cutting part of the semi-automatic biopsy needle is visualized

Figure 10. On the transverse (10a) and sagittal (10b) MP-tomograms, a conductive needle (arrow) and the area of presacral tissue infiltration (*) were visualized during the biopsy.

11. On the transverse (11a) and sagittal (11b) MP-tomograms, a trepan biopsy needle (arrow) located in the modified vertebral arch L5 (*) is visualized.

The procedure for implementing the method

Preliminary preparation of the patient for a biopsy is the necessary emptying of the intestines and bladder, as well as the use of sedatives and bacterial prophylaxis preparations. The patient is dressed in a surgical suit of cotton fabric, thereby eliminating the undesirable decrease in the information content of the resulting image. Given the known localization of the patient’s area of interest, they are positioned on the table of a magnetic resonance imager in one of four positions: 1) with the head in the aperture of the magnet lying on its back; 2) legs in the aperture lying on the stomach; 3) head into the aperture of a magnet lying on his stomach; 4) feet in the aperture of a magnet lying on his back. The patient should be maximally shifted to the right with left-sided localization of the affected area and, accordingly, should be shifted to the left with right-handed localization of the affected area. Laser centralization of the survey field and the location of the surface radio frequency (RF) coil is carried out taking into account the localization of a previously known region of interest. Two main pulsed sequences of the fast spin echo TSE (Turbo spin echo) are used to obtain weighted images (TI) by the relaxation time T2 in the sagittal and axial planes with the following parameters: repetition time (TR) - 2130 ms, echo time (TE) - 105 ms , the number of image collection is 1, the number of slices is 10, the thickness of the obtained slice is 5 mm, without gaps, the duration of one pulse sequence is 38 seconds.

The MP images in the sagittal and axial planes determine the region of interest and its center. Using a laser mark built into the apparatus, a transverse line is drawn on the patient’s skin with respect to the tomograph table using a special marker, which topically corresponds to the middle zone of interest in the longitudinal axis Z of the magnet aperture. On this transverse line, closer to the center of the region of interest, the fat capsule is randomly stirred (Fig. 1) and fixed with a medical plaster.

Impose a surface RF coil and repeat the examination to obtain T2 VI MP images in the axial plane (Fig. 2). According to these images, the parameters necessary for the safe conduct of a biopsy needle are calculated (Fig. 3), excluding the possibility of damage to critical organs, vascular and neural structures. To determine the point of injection of the biopsy needle in the images, the distance between the fat capsule and the point connecting the center of the region of interest and the intersection of the safe path of the needle with the skin (pos. A in Fig. 3) is measured. This distance and, accordingly, the point of injection of the biopsy needle is determined on the transverse line previously applied to the patient’s skin, marking their intersection with a longitudinal mark by a special marker. The angle of injection is set — and the angle between the vertical line passing through the center of the region of interest and the line connecting the point of injection of the biopsy needle and the center of the region of interest, which corresponds to the safe trajectory of the biopsy needle. Measure the distance from the surface of the skin, depending on the location of the region of interest, either to the peritoneum, or to the muscular fascia, or to the periosteum (item B in Fig. 3); the distance from the skin surface but the beginning of the region of interest (pos. B in Fig. 3) and the distance from the skin to the edge of the region of interest (pos. G in Fig. 3).

The intervention field is treated on the skin surface in the area of intervention, surrounded by sterile material. Then, skin and soft tissues are anesthetized with a local anesthetic, taking into account a certain entry point of the biopsy needle (pos. A in Fig. 3). and the calculated distance from the skin surface to the peritoneum / muscle fascia / periosteum (pos. B in Fig. 3). To the depth of anesthesia, either a conductor needle (for biopsy of soft tissues), or an aspiration needle (for aspiration of fluid contents), or a needle for trepan biopsy (for biopsy of bone structures) is inserted (Fig. 4). Next, a control study is performed to obtain T2 VI MP images in the sagittal and axial planes, along which the inclination and depth of the needle are controlled. The depth of gradual immersion of the biopsy needle is determined by the calculated distance from the skin surface to the beginning of the region of interest (pos. B in Fig. 3) and is monitored on MP images in two planes. Upon reaching the required depth of immersion, in the case of a soft tissue biopsy, a semi-automatic needle is immersed in the conductor needle and, taking into account the calculated distance from the skin surface to the edge of the region of interest (pos. G in Fig. 3), the depth is selected and histological material is collected. In cases of aspiration biopsy, when the required depth of immersion of the aspiration needle is reached, its additional immersion is performed to take the necessary material. When the required depth of immersion of the needle for trepan biopsy is reached, the stylet of the needle is extracted and the needle is further immersed by rotational movements based on the distance from the skin surface to the edge of the region of interest. Histological material is obtained, placed in a vial of formalin and sent for subsequent morphological examination.

            Examples of the method.

     Example 1

Patient B.L.K. case history No. 5728, 53 years old, with a diagnosis of cervical cancer T2NxM0 in 2008, received combined radiation therapy for the pelvic area with remote radiation therapy (DLT) from 2 opposite tangential fields: single total dose (ROD) of 2 g, total total dose (SOD) of 40 Gy and iv cavity radiation therapy: ROD 7 g, SOD 49 Gy, as well as a course of chemotherapy.

After the end of treatment, pain along the intestines, abundant discharge of blood and mucus from the rectum appeared. Since 2010, she has been observed in the department of radiation injuries of the Federal State Budget Institution MRRC with a diagnosis of Cervical Cancer T2NxM0. Combined treatment in 2008. Late radiation ulcerative necrotic rectitis, often recurring rectal bleeding. Late radiation hemorrhagic cystitis. Secondary (radiation) atrophic colpitis. Intrathitase radiation fibrosis. Secondary (radiation) p / sacral plexopathy with a primary lesion of the distal sections. In the same 2010, on the basis of a gynecological examination in the right parametrium, a gross volumetric and motionless severity was revealed to the pelvic wall.

The patient was referred to MRI of the pelvic organs, according to which no data were obtained for tumor recurrence in the pelvic region, the MP picture corresponds to postradiation changes in the pelvic cavity. In 2011, an infiltrate was examined and diagnosed in the right parametrium, extending to the walls of the pelvis, moderate hydronephrosis on the right. Conducted 3 courses of polychemotherapy (PCT). At the beginning of 2012, she was re-examined, diagnosed with the formation of a small pelvis, involvement of the iliac vessels, compression of the right ureter.

In March 2012, a nephrureterectomy was performed, as well as an examination of the pelvic organs, on the basis of which no data were found for relapse of the tumor, a marked adhesion process and fibrous tissue in the projection of the external iliac vessels on the right causing obstruction of the right ureter were noted.

In July 2012, the patient performed computed tomography with contrast enhancement, revealed a volumetric formation of the small pelvis on the right, near the uterine wall, of a benign nature and due to the scar-adhesion process.

In August 2012, the patient entered the department of radiation injuries of the Federal State Budgetary Institution MRRC with complaints of pain in the right half of the abdominal cavity. Based on the data of ultrasound and MRI, it is not possible to clearly determine the nature of changes in the pelvis. A targeted biopsy was recommended (Figure 5). With this complex spatial localization and the presence of nearby located (involved) large vascular and neural structures, the method of biopsy control has become magnetic resonance imaging (Fig.6, 7). This patient was positioned and the area of interest was determined by MP images in the sagittal and axial planes. In relation to the placed fat capsule, a biopsy needle was introduced, the tilt angle and depth of which was gradually monitored on MP images. Upon reaching the required depth of introduction of the biopsy needle to the area of interest, histological material was obtained, which was directed to morphological examination (Fig. 8). A relapse of cervical cancer at the pelvic wall has been confirmed. During and after the biopsy of complications, in the form of internal bleeding and infection of the post-biopsy channel, was not observed.

Thus, in this example with a complex anatomical situation, only thanks to the applied method was obtained informative histological material with minimal trauma and a low risk of complications, which contributed to the establishment of an accurate diagnosis and the appointment of appropriate treatment.

Example 2

Patient M.O.A., medical history No. 6629, 46 years old with a diagnosis of cervical cancer T2N0M0 underwent surgical and radiation treatment. It has been observed for several years with a diagnosis of intra-pelvic radiation fibrosis. Over the past year, pain in the pelvic area has intensified. According to MRI and ultrasound, an infiltration zone was identified in the vaginal stump and right parametrium, which, unambiguously, cannot be judged on the nature of it. A targeted biopsy of this area is recommended. The method we have proposed is performed with positioning and determining the region of interest by MP images in the sagittal and axial planes. In relation to the placed fat capsule, a biopsy needle was introduced, the tilt angle and depth of which was gradually monitored on MP images. Upon reaching the required depth of introduction of the biopsy needle to the area of interest, histological material was obtained, which was directed to morphological examination (Figure 9). A relapse of cervical cancer has been established. No complications were observed.

Example 3

Patient N.V.N., medical history No. 1003, diagnosed with colorectal cancer T3N1M0, received combined radiation treatment for the pelvic area. It is observed with postradiation changes in organs and tissues of the small pelvis. Examination in the persacral region revealed a zone of infiltrative changes. It is not possible to unambiguously determine the nature of the changes. The method we have proposed is performed with positioning and determining the region of interest by MP images in the sagittal and axial planes. In relation to the placed fat capsule, a biopsy needle was introduced, the tilt angle and depth of which was gradually monitored on MP images. Upon reaching the required depth of introduction of the biopsy needle to the area of interest, histological material was obtained, which was directed to morphological examination (Figure 10). The diagnosis of intra-pelvic post-radiation fibrosis is established. No complications were observed.

Example 4

Patient L.E.N., medical history No. 5790, 45 years old, with a diagnosis of bladder cancer T36N1M0, received appropriate chemoradiation treatment. When conducting MRI in the right arch and the transverse process of the L5 vertebra, the zone of infiltrative changes was visualized, which was not reflected during CT and skeletal osteoscintigraphy. The discrepancy between the results of these research methods required targeted biopsy of this area. The method we have proposed is performed with positioning and determining the region of interest by MP images in the sagittal and axial planes. In relation to the placed fat capsule, a needle was introduced for a tepan biopsy of bone tissue, the tilt angle and depth of which was gradually monitored on MP images. Upon reaching the required depth of introduction of the biopsy needle to the area of interest, histological material was obtained, which was directed to morphological examination (Figure 11). A metastatic lesion of the L5 vertebra was established. No complications were observed.

Confirmation of the achievement of a technical result.

This method was performed in 10 patients, of which 8 patients at the time of the study already had verified cancer and the purpose of the biopsy in these cases was the exclusion of metastasis or recurrence of the process in the organs and tissues of the pelvis. In 2 patients with ambiguously diagnosed pathological changes according to ultrasound, CT, and MRI, the goal was to exclude the oncological process in the organs and tissues of the pelvis.

Table 1. General characteristics of patients are presented in table. one. Primary Floor Age (years): tumor localization Male Female median Prostate cancer one 0 61 glands Bladder cancer one 0 54 Cervical cancer 0 four 45 Uterine cancer 0 one 48 Rectal cancer one 0 58 No primary tumor detected one one 47 Total four 6 -

In 4 cases, bone structures were the object of intervention, and in 6 cases, soft tissues of the pelvic area.

Localization of the biopsy area is presented in table 2.

table 2 Characterization of the localization of the biopsy object in 10 patients Primary tumor location Localization of the biopsy area Bone structures Ovaries Large oil seal Soft tissue of the pelvic wall Presacral soft tissue Prostate cancer one Bladder cancer one Cervical cancer one 3 Uterine cancer one Rectal cancer one No primary tumor detected one one Total four one one 3 one

In all 100% of cases, informative histological material was obtained, which made it possible to accurately establish the nature of changes in the pelvic area and to adjust the tactics of maintaining these patients.

In 80% of cases, the presence of a primary or recurrent oncological process in the organs and tissues of the pelvis was confirmed, which changed the treatment tactics and prognosis in these patients. In all cases, after the results of the biopsy, chemotherapy or targeted radiation therapy initiated in a timely manner could reduce the severity of the pain syndrome and reduce the size of the revealed pathological changes.

In 20% of cases, the changes were benign, which saved patients from unnecessary antitumor treatment.

Claims (1)

A method for the diagnosis of pelvic tumors, including positioning the patient and determining the area of interest for percutaneous puncture biopsy followed by taking and examining the histological material, characterized in that they carry out MRI, calculating the parameters of the biopsy needle insertion, excluding the possibility of damage to critical organs, vascular and neural structures, the point of injection of the needle is determined on a transverse line drawn on the patient’s skin and topically corresponding to the zone of interest, taking into account the placement constant thereon adipose capsule puncture needle set angle by the angle between a vertical line passing through the center of the region of interest, and a line connecting the biopsy needle puncture point and the center of the region of interest, with the subsequent control of the required depth of immersion and inclination of the needle.

Images