Cervical cancer is currently the most common gynecological malignancy in China. Although the screening of this disease has been gradually paid attention to in recent years, few people in rural areas go to hospitals for regular checkups. Meanwhile, the incidence of cervical cancer is gradually increasing, as HPV infection is getting heavier and heavier in recent years, and the trend is getting younger and younger. For the treatment of cervical cancer, surgery, radiotherapy and chemotherapy are the main treatment methods. Surgery is only suitable for early stage cervical cancer patients, while radiotherapy should be the main treatment for most of the patients with middle and late stage cervical cancer. Although radiotherapy can usually achieve better treatment results, local recurrence is still the biggest problem for patients with limited advanced cervical cancer. Therefore, one of the current research priorities for cervical cancer is to improve the effectiveness of various treatment options and reduce local recurrence after radiotherapy. In recent years, many colleagues have tried the combination of radiotherapy and chemotherapy in the treatment of cervical cancer. There are several ways of combined chemotherapy and radiotherapy, namely, sequential chemotherapy and radiotherapy, synchronous chemotherapy and radiotherapy, and adjuvant chemotherapy after radiotherapy. Theoretically, the combination of chemotherapy and radiotherapy should benefit patients with limited advanced cervical cancer in two ways, which include: 1) chemotherapy may control subclinical metastases or undetected metastases outside the radiation area; 2) chemotherapy may enhance the effect of radiotherapy through different mechanisms. The latter may be achieved through the following mechanisms: firstly, chemotherapy enhances the killing power of radiation on cells, secondly, the cell synchronization caused by chemotherapy makes the tumor cells more sensitive to radiation, and finally, chemotherapy may prevent the cells from repairing the radiation damage. Neoadjuvant chemotherapy or Preradiation chemotherapy is given to patients before radiotherapy to reduce the size of the tumor and then start radiotherapy. However, the prognosis of patients treated with sequential chemotherapy and radiotherapy is not better than that of radiotherapy alone, and therefore, many patients do not consider the sequential combination of chemotherapy and radiotherapy to be a good treatment option. However, for those patients who are planned to have surgery, prior chemotherapy can significantly reduce or disappear the size of tumor, and give patients with limited advanced cervical cancer a very valuable opportunity to have surgery, and such patients are currently considered to have an improved prognosis; while for patients who are not satisfied with the effect after prior chemotherapy, the remedy can only be radiotherapy at this time, although the prognosis is not better than radiotherapy alone, but in practical terms Although the prognosis is not better than that of radiotherapy alone, it is no worse than that of radiotherapy alone in practical terms. Adjuvant chemotherapy after radiotherapy is used for patients whose radiotherapy has been completed, but whose lesions are too extensive or have not completely disappeared at the end of radiotherapy. Chemotherapy is an adjuvant treatment to radiation therapy, but it has limited local effect due to some reactions caused by radiation, but it has some value for the control of distant metastases. Comcurrent chemoradiation refers to the simultaneous administration of chemotherapy and radiotherapy, i.e., chemotherapy is given at the same time as radiotherapy. The emphasis is on synchronization, i.e., chemotherapy is given at the beginning of radiation therapy, during radiation therapy, and at the end of radiation therapy. This treatment is more likely to reflect the enhancing and synchronizing effect of chemotherapy on radiotherapy, and there is no delay between the two treatments. The absence of an interval between the two treatments also minimizes adverse interactions between the two treatments, such as the effect of radiotherapy on chemotherapy and the effect of chemotherapy on radiotherapy. However, it should be noted that while chemotherapy increases the sensitivity of the tumor to radiotherapy, the chance of serious injury caused by radiation will also be greatly increased. There are several requirements for the chemotherapy drugs used in radiotherapy. Firstly, chemotherapeutic drugs should be effective for cervical cancer, secondly, the simultaneous application of chemotherapeutic drugs and radiotherapy should not reduce the effect of radiotherapy, and finally, the toxic effects of chemotherapeutic drugs should be limited, or at least should not overlap with the adverse effects caused by radiation. Currently, the main drugs used for radiotherapy include hydroxyurea, cisplatin, 5-fluorouracil and mitomycin. Here we elaborate on the research and application of each drug in radiotherapy separately. 1.Hydroxyurea: As early as the 1960s, some people conducted an in vitro study on the synchronization of chemotherapeutic drugs in radiotherapy and found that hydroxyurea, as an inhibitor of RNA reductase, could enhance the killing of tumors when applied simultaneously with radiotherapy. A large number of studies from the 1970s should confirm the prognostic benefit of hydroxyurea in combination with radiotherapy for limited advanced cervical cancer, and there are some valuable prospective randomized studies. A prospective, multicenter, randomized study by GOG, which included 90 patients with limited advanced cervical cancer, combined hydroxyurea and radiation therapy and found significant differences between the radiotherapy and radiation therapy alone groups, with remission rates of 68% and 48%, tumor-free intervals of 13.6 months and 7.6 months, and median survival times of 19.5 months and 10.7 months, respectively. Therefore, the addition of hydroxyurea to radiation therapy was the standard treatment recommended by the GOG at that time for the treatment of limited advanced cervical cancer, but for some reason this standard has not been widely used in clinical practice. Therefore, the GOG conducted a long-term prospective randomized study in 1993, which found that the administration of hydroxyurea along with radiotherapy may change the prognosis of patients with cervical cancer. 2. Cisplatin: Since the 1980s, a large number of randomized clinical studies have focused on simultaneous treatment with cisplatin-based chemotherapy and radiotherapy to compare the prognosis of radiotherapy with that of radiotherapy alone. Why is cisplatin-based chemotherapy chosen as the radiotherapy regimen? There are several reasons: 1) cisplatin itself is effective as a single drug chemotherapy for recurrent cervical cancer; 2) cisplatin has a very mild effect on bone marrow; 3) in vivo and in vitro studies have found that when cisplatin is combined with radiotherapy, it can enhance the killing of tumor cells by radiation. The latter effect was achieved by inhibiting the repair of sublethal radiation damage and sensitization of hypoxic cells. The results of an animal study showed that cisplatin-based chemotherapy was most effective when given before the start of radiotherapy, and the enhancement of radiation for tumor cell killing was most pronounced when given after radiotherapy. 3.5-Fluorouracil: 5-Fluorouracil is one of the most commonly used chemotherapeutic drugs in synchronous radiotherapy, and it is often used in combination with cisplatin. As far as radiotherapy is concerned, the mechanism of action of 5-fluorouracil may be through its interference with the repair of radiation damage. A series of in vitro trials on the use of 5-fluorouracil in radiotherapy have been conducted by many colleagues, and a study by Byfield et al. found that synchronization was not achieved until cells were exposed to 5-fluorouracil for at least 24 hours after the initiation of radiotherapy, and this result was confirmed in another clinical trial, which further supports this approach to 5-fluorouracil administration. conducted a randomized study of radiotherapy for limited advanced cervical cancer with continuous titration of 5-fluorouracil and found that 5-fluorouracil was more effective in relatively early stage (stages Ib2, IIa, IIb) cervical cancer with unilateral parametrial infiltration, while the results were unclear in more extensive patients. This study also found that the effect of 5-fluorouracil varied with the use of the drug, such as daily dosing with continuous drip was more effective than twice daily, the reason for which seems to be difficult to explain. 4. Combination of drugs: The most common way is the combination of cisplatin and 5-fluorouracil. This is because the combined toxic effects of both are very limited and do not significantly increase the toxic effects of radiotherapy. Although the combination of hydroxyurea and fluorouracil can theoretically enhance the effect of radiotherapy, the combination of the three drugs is rarely used in radiotherapy for cervical cancer because it may significantly increase the toxic effects of radiotherapy to the extent that it cannot be controlled. The effect of radiotherapy on the prognosis of cervical cancer has not been solved for a long time. Until early 1999, due to the conclusion of five large-scale clinical studies, the results confirmed that radiotherapy could significantly improve the prognosis of cervical cancer patients compared with radiotherapy alone or radiotherapy alone combined with hydroxyurea, so the American Cancer Institute (NCI) issued a clinical notice, pointing out that due to the results of these five large-scale clinical trials, it is recommended that radiotherapy be given to cervical cancer patients with cisplatin-based chemotherapy. These five representative clinical trials are described below. 1. The first clinical trial was a randomized study conducted by the Gynecologic Oncology Group (GOG) and the Southwest Oncology Group (SOG) in the United States. The aim was to evaluate the role of radiotherapy combined with hydroxyurea (HU) in combination with fluorouracil (F) and cisplatin (P) in limited advanced cervical cancer, and also to estimate the toxicity. All patients were biopsy-proven with different histological types of cervical cancer and clinical stages IIB, III and IVA of FIGO, respectively, and patients were randomly divided into. Radiotherapy group (PF+RT) and radiotherapy group (RT+HU). 388 patients, of which 368 were evaluable cases, were randomly divided into PF+RT group (177) and RT+HU group (191). Gastrointestinal side effects were found to be similar in both groups, with severe granulocytopenia of 4% and 24%, respectively, while tumor-free survival time was significantly higher in the radiotherapy group (P = 0 .033) and survival was better in the radiotherapy group (P = .018). This study confirms that combining cisplatin and fluorouracil with radiation therapy for patients with limited advanced cervical cancer improves prognosis and results in longer tumor-free survival and higher survival rates. 2. The second clinical trial was a clinical study conducted by the Radiation Therapy Oncology Collaborative Group (RTOG) in the U.S. The authors’ main objective was to compare the effects of radiotherapy alone with those of radiochemotherapy. From 1990 to 1997, 403 patients with stage IIB-IVA cervical cancer with tumor diameter greater than 5 cm or lymph node involvement were admitted and randomized: one group received 45 Gy of pelvic and para-aortic lymph node irradiation, and the other group was given 45 Gy of pelvic irradiation. Two concurrent courses of PF chemotherapy (days 1-5 and 22-26 of radiotherapy) were received, followed by 1-2 sessions of low-dose rate intracavitary therapy, with a third course of chemotherapy given at the time of the second intracavitary treatment. Of the 403 available cases, 193 evaluable cases in each group had a median follow-up of 43 months, with 5-year survival rates of 73% and 58% in the radiotherapy and radiotherapy alone groups, respectively (P=0.004), and 5-year tumor-free survival rates of 67% and 40%, respectively.