Radiation therapy for cervical cancer (hereinafter referred to as radiotherapy), which started with intracavitary radium therapy more than a century ago, is still one of the basic treatment methods for cervical cancer. According to FIGO International Annual Report, between 1982 and 1993, more than 80% of cases of cervical cancer were treated with radiotherapy worldwide. Radiotherapy can be used for all stages of cervical invasive cancer and for patients with in situ cancer who are not suitable for surgery; for patients with advanced stage and not suitable for radical radiotherapy, radiotherapy can also be used for palliative treatment to improve symptoms and prolong life. In recent decades, there have been many advances in radiotherapy for cervical cancer. The current situation and progress of radiotherapy for cervical cancer are briefly described below.
1.Development of intracavitary radiotherapy technology
Intracavitary radium therapy has opened up a new era of cervical cancer treatment, but the problem of staff intake has not been solved for a long time. Since the 1960s, the intracavitary reloading technology has solved the problem of staff protection. The postloading treatment has evolved from manual postloading to mechanical control to today’s computer-controlled, multifunctional postloading machines with treatment planning systems. These multifunctional afterloaders are now widely used in radiotherapy for cervical cancer.
Traditional intracavitary therapy is applied with low dose rate intracavitary therapy, which has accumulated more experience due to longer application time. Along with the emergence of afterloading technology, high-dose rate intracavitary therapy began to be applied in radiotherapy of cervical cancer. High-dose rate treatment is particularly popular in developing countries due to its short duration, convenience to patients and increased number of patients treated. In China, high-dose-rate therapy is now mostly used, and the radiation sources are mostly 192Ir sources with easy protection and short half-life. In addition, the miniaturization of radiation sources makes brachytherapy, especially tissue interposition treatment more convenient.
Among the radiation sources, the clinical application of 252 californium has been a progress in recent years. 252 californium as a neutron source for intracavitary radiotherapy has been clinically applied in several countries, and has been used for post-mounted intracavitary radiotherapy. China also has 252 californium rear-loading machine and used for cervical cancer radiotherapy clinical reports.
2.Improvement of external irradiation technology
Extracorporeal irradiation for cervical cancer can make up for the shortage of intracavitary treatment by increasing the dose in the parametrial infiltration area and lymphatic metastasis area beyond the A spot. Over the past century, extracorporeal irradiation treatment machines have gone through three stages from conventional X-ray treatment machines to 60 cobalt treatment machines to the current application of multiple gas pedals. The continuous increase in energy has increased the deep dose and decreased the skin dose, improving the efficacy and reducing the side effects. In terms of clinical use techniques, in addition to vertical irradiation, there are also reports of rotational, pendulum and isocentric techniques applied in cervical cancer radiotherapy. Moreover, with the development of computer technology and imaging technology, new techniques such as γ-knife, χ-knife, 3D conformal irradiation and intensity modulation therapy have emerged in recent years. These new technologies are still in the exploratory stage and cannot replace the current conventional radiotherapy combining external and intracavitary irradiation.
3.Several issues to be noted in simple radiotherapy for cervical cancer
Different radiotherapy units use different machines and different radiotherapy methods, and they have accumulated their own experience, but there are some common principles and issues that should be noted in simple radiotherapy for cervical cancer.
3.1. Elimination amount The elimination amount refers to the dose of exophytic and large tumor to restore it to the normal cervical shape roughly. Generally, when starting radiotherapy, vaginal treatment or tissue insertion is performed. It should be noted that it takes time to eliminate the tumor, so when the treatment is started, the elimination amount is given at the beginning of the whole pelvic irradiation, and when the whole pelvic irradiation is finished, the cervical shape can be restored.
Nogachi et al. reported that the invasion of uterine cavity was 7.8% in stage Ib, 25.5% in stage IIa, 38.2% in stage IIb, and the total involvement rate was 21.6%, and the involvement of uterine body was often accompanied by lymphatic and surrounding tissue metastasis. Therefore, the uterine body should not be ignored, and the amount of uterine body involvement should be noted. If only the cervical and parametrial doses are considered and the uterine body is neglected, it may easily lead to recurrence of the uterine body.
3.3. Uterine displacement It is common that for some reasons, such as inflammation, tumor, pelvic surgery, etc., the uterus is often displaced laterally instead of in the pelvis. In this case, the effect on the parametrial dose should be considered when the uterine cavity is treated (the dose on the away side is reduced and the dose on the displaced side is increased). The cause of the displacement should be carefully analyzed and the in vitro dose should be adjusted to compensate for the effect on the parametrial dose.
3.4. Pay attention to the anatomical position of the uterine cavity and vagina The normal uterine body is tilted forward and the uterus is at a certain angle to the vagina. Separate treatment of the uterus and vagina can reduce this effect and reduce the dose rate at the level of the uterine orifice, rectum and bladder area, which is beneficial to reduce complications.
3.5. Individual treatment A certain protocol may not be suitable for each specific case, and should be adjusted on the basis of the above principles according to the patient’s specific situation and treatment equipment and experience, e.g.: early infiltrating carcinoma of the cervix, pure intracavitary radiotherapy is sufficient; with multiple and narrow vaginal invasion and a cavernous cervix combined with inflammation, treatment starts with total pelvic irradiation, and the dose of total pelvic irradiation can be increased and the dose of intracavitary treatment reduced accordingly. For cervical stump cancer, the extracorporeal dose should be increased appropriately, and the intracavitary dose should be reduced due to the absence of uterine volume. The specific dose should be considered according to the length of the cervical canal at the stump, vaginal elasticity, lesion condition and extracorporeal irradiation mode and dose. In case of combined ovarian tumor or inflammatory mass, surgical resection can be considered.
4. Combined treatment of radiotherapy and surgery
The combined treatment of radiotherapy and surgery includes preoperative irradiation and postoperative irradiation.
The value of radiotherapy after radical surgery for cervical cancer is still controversial. Some scholars believe that postoperative irradiation can improve the survival rate; however, some scholars hold the opposite view that postoperative irradiation not only cannot improve the survival rate, but also increases the incidence of serious complications. In our opinion, we should strictly control the indications of surgery for cervical cancer, and should not perform inappropriate surgery for cases that are not suitable for surgery, and use radiotherapy to “fill the hole”. Of course, for some cases with poor prognostic factors such as lymphatic metastasis in pelvis or abdominal aorta or tumor thrombus in blood vessels and lymphatic vessels, and cases with unclear or suspected unclear cut edges, postoperative radiotherapy can be considered as an adjunct. Most of the postoperative radiotherapy is based on external irradiation, while intracavitary treatment is given to those with cancer in the vaginal stump. It should be noted that the occurrence and severity of postoperative radiation complications are related to the extensiveness of the surgery, the area of the radiation field and the dose.
Preoperative radiotherapy has received attention in recent years, mainly because of the poor outcome of surgery alone in cases with poor prognostic factors, such as stage Ib2 cases with large localized tumors. Preoperative intracavitary radiotherapy has been found to improve local conditions, reduce tumor size, and improve surgical resection rates. Since radical pelvic radiotherapy followed by extensive hysterectomy and pelvic lymphatic dissection has many complications, in most units, preoperative radiotherapy is usually given only intracavitary treatment with 1/3 to 1/2 of the full amount of intracavitary radiotherapy, and since tumor elimination requires a certain amount of time, it is important not to lose the significance of preoperative radiotherapy by premature surgery after radiotherapy. If the half amount of intracavitary radiotherapy is given before surgery, the surgery can be performed after two weeks.
5.The combination of radiotherapy and chemotherapy
In the combination of radiotherapy and chemotherapy, chemotherapy followed by radiotherapy (so-called neoadjuvant chemotherapy) and concurrent radiotherapy and chemotherapy have been studied more in recent years. Since cervical cancer lesions are more limited and cervical cancer is more sensitive to radiotherapy, and some clinical trials have not confirmed that neoadjuvant chemotherapy can improve the efficacy of radiotherapy for cervical cancer, neoadjuvant chemotherapy for cervical cancer is not advocated to be routinely used for radiotherapy patients with cervical cancer. On the other hand, regarding the use of chemotherapy and radiotherapy for cervical cancer treatment at the same time, many clinical trials abroad have shown encouraging conclusions, and many units in China are currently conducting clinical observation of this treatment plan.
Current status of prevention and care of cervical cancer
I. Precancerous lesions of cervical cancer: CIN
l 1.Cervical intraepithelial neoplasia (CIN)
l 2.Cervical atypical hyperplasia (Dysplasia)
l 3, Squamous intraepithelial lesion (SIL): including
Low grade squamous intraepithelial lesion (LSIL) and high grade squamous intraepithelial lesion (HSIL).
Precancerous lesions of the cervix are diagnosed by
A combination of cytology + colposcopy + cervical canal scraping, and cervical conization if necessary.
Attachment: cytological advances
TBS return modality
Computer-assisted cell detection system i.e. CCT (Cellular Computer Topography)
Neoplattice thin-layer liquid-based cytology smear i.e. TCT (Thinprep Pap)
TBS report content
Includes three parts
1. Total diagnostic range: in the normal range or otherwise.
2. Assessment of the specimen taken: satisfactory, satisfactory but limited to…
Unsatisfactory specimens.
3. Specific description of what is seen microscopically.
Specific description of TBS in the form of
Benign cellular changes
Infection.
Reactive cellular changes
Epithelial cell changes.
Squamous epithelial cells
Atypical squamous epithelial cells without deterministic significance
Low grade squamous intraepithelial lesions
High grade squamous intraepithelial lesions
Squamous epithelial cell carcinoma
Glandular epithelial cells
Endometrial cells (benign, in postmenopause)
Atypical glandular epithelial cells of undefined diagnostic significance
Adenocarcinoma of the uterine cervix
Endometrial adenocarcinoma
Ectopic adenocarcinoma
CIN is managed as follows.
CIN grade I: with follow-up conditions → regular examination and close follow-up, physiotherapy may also be used.
CIN grade II: physical therapy is preferred, if the lesion is extensive and extends into the cervical canal → conization (e.g. LEEP), if combined with uterine fibroids or ovarian cysts, voluntary total hysterectomy at older age can also be considered.
CIN grade Ⅲ: Preferred surgical treatment, young people with fertility requirements or those requiring improved quality of life, lesions are more limited → conization (e.g. LEEP). Extra-fascial hysterectomy is usually required.
Pregnancy combined with CIN: Since 75% of CIN lesions during pregnancy regress within six months after delivery, follow-up observation is more preferable.
Several questions about HPV and cervical cancer
1.What is HPV? How does it lead to cervical cancer?
2.Can HPV infections be treated?
3.If I tested positive for HPV, what does this mean for me?
4.If I tested positive for HPV, what does this mean for me?
Diagnosis of cervical cancer.
In addition to tumor site, tissue type, stage and cell grading, the diagnosis of cervical cancer should also include the general type of tumor.
The general pathological types are
l 1. celiac type.
l 2. exophytic type also known as cauliflower type.
l 3. endophytic type, also known as nodular type.
l 4. ulcerated type also known as cavernous type.
Changes in the staging of cervical cancer
Treatment of cervical cancer
(I) Surgery
(2) Radiotherapy
External irradiation
Intracavitary treatment
(C) Chemotherapy: improved status
1. Chemoradiotherapy
2.Neoadjuvant chemotherapy
(I) Surgical treatment
About the name and scope of uterine surgery.
1, cervical conization: including Loop electrosurgical excision procedure (LEEP) and cold knife conization.
Features of Loop electrosurgical excision procedure (LEEP): 1) simple and easy to operate; 2) small and easy to use instruments; 3) painless for the patient, little bleeding, no anesthesia required, can be performed on an outpatient basis; 4) little thermal damage to the tissue due to the high frequency current used by the machine, which does not affect the histopathological observation, It is worth popularizing in the diagnosis and treatment of CIN.
2.Total hysterectomy
3.Extra-fascia hysterectomy
4.Subextensive hysterectomy
5.Extensive hysterectomy
6.Radical hysterectomy for cervical cancer
Post-surgical treatment routine for cervical cancer
1. Removal of catheter 5-7 days after secondary extensive hysterectomy.
2. Treatment of catheter after extensive hysterectomy with pelvic lymph node dissection: open continuously for 3 days after surgery; open regularly from day 3-4, open once every 2-4 hours, and start bladder irrigation once a day with 1:10,000ml of potassium permanganate solution and warm up to 37-38oC, keep for 20-30 minutes after irrigation and then discharge; remove catheter on day 7-9 as appropriate On the 7th-9th day, the catheter was removed at the discretion of the patient, and the patient was exercised to urinate by himself. If the residual urine is >100ml or cannot be discharged after catheter removal, the urinary catheter should be kept open regularly and bladder irrigation should be continued, together with acupuncture and Chinese medicine.
3. Treatment of drainage tube after extensive hysterectomy with pelvic lymph node dissection: the vaginal drainage tube was removed 1 cm outward 24 hours after surgery, and the head was elevated to facilitate drainage, and it was removed 48-72 hours after surgery. Drainage of abdominal drainage tube 48-72 hours after surgery