Neutron therapy in cervical cancer: results of a phase III RTOG Study

Fast and Furious: Fast Neutron Therapy in Cancer Treatment

Fast neutron therapy has been used for decades. In conjunction with recent advances in photonic techniques, fast neutrons are no longer of much oncologic interest, which is not unequivocally positive, given their undoubted therapeutic value. This mini-review recalls the history of medical research on fast neutrons, considers their physical and radiobiological properties alongside their benefits for cancer treatment, and discusses their place in modern radiation oncology.

A prospective randomized trial comparing accelerated concurrent chemoradiotherapy with conventional concurrent chemoradiotherapy in locally advanced carcinoma cervix (IIA-IVA)

Introduction

Cervical cancer ranks fourth in women worldwide. The management requires a multidisciplinary approach. Concomitant chemoradiotherapy with cisplatin, followed by brachytherapy, is the standard approach. Accelerated radiotherapy (ART) can be used to decrease the treatment duration which can further lead to better outcomes.

Materials and Methods

Stages II, III, and IVA of carcinoma cervix were studied for 1 year. Ninety patients were randomized in control and study arms, 45 patients in each arm. The total dose of radiation was 50 Gy/25#/5 weeks from Monday to Friday in the control arm and 50 Gy/25#/4 weeks from Monday to Saturday in the study arm, with injection cisplatin 40 mg/m ² intravenous infusion weekly in both the arms.

Results

The response was similar in both the arms at the first follow-up as well as at median follow-up. However, acute toxicities in the ART arm were more, but they were managed conservatively.

Conclusion

ART can be used in patients of cervical cancers to decrease the total treatment time. The results were similar in both the groups but need to be studied over more number of patients.

Radiation therapy oncology group gynecologic oncology working group: comprehensive results

The purpose of this report was to comprehensively describe the activities of the Gynecologic Oncology Working Group within the Radiation Therapy Oncology Group (RTOG). Clinical trials will be reviewed as well as translational science and ancillary activities. During the past 40 years, a myriad of clinical trials have been performed within the RTOG with the aim of improving overall survival (OS) and decreasing morbidity in women with cervical or endometrial cancer. Major study questions have included hyperbaric oxygen, neutron radiotherapy, altered fractionation, hypoxic cell sensitization, chemosensitization, and volume-directed radiotherapy.RTOG 7920 demonstrated improvement in OS in patients with stages IB through IIB cervical carcinoma receiving prophylactic para-aortic irradiation compared to pelvic radiation alone. RTOG 9001 demonstrated that cisplatin and 5-FU chemoradiotherapy to the pelvis for advanced cervix cancer markedly improved OS compared to extended field radiotherapy alone. More recent trials have used radioprotectors, molecular-targeted therapy, and intensity-modulated radiation therapy. Ancillary studies have developed clinical target volume atlases for research protocols and routine clinical use. Worldwide practice patterns have been investigated in cervix, endometrial, and vulvar cancer through the Gynecologic Cancer Intergroup. Translational studies have focused on immunohistochemical markers, changes in gene expression, and miRNA patterns impacting prognosis.The RTOG gynecologic working group has performed clinical trials that have defined the standard of care, improved survival, and added to our understanding of the biology of cervical and endometrial cancers.

Basics of particle therapy II biologic and dosimetric aspects of clinical hadron therapy

Besides photons and electrons, high-energy particles like protons, neutrons, ⁴He ions or heavier ions (C, Ne, etc) have been finding increasing applications in the treatment of radioresistant tumors and tumors located near critical structures. The main difference between photons and hadrons is their different biologic effect and depth-dose distribution. Generally speaking, protons are superior in dosimetric aspects whereas neutrons have advantages in biologic effectiveness because of the high linear energy transfer. In 1946 Robert Wilson first published the physical advantages in dose distribution of ion particles for cancer therapy. Since that time hadronic radiotherapy has been intensively studied in physics laboratories worldwide and clinical application have gradually come to fruition. Hadron therapy was made possible by the advances in accelerator technology, which increases the particles' energy high enough to place them at any depth within the patient's body. As a follow-up to the previous article Introduction to Hadrons, this review discusses certain biologic and dosimetric aspects of using protons, neutrons, and heavy charged particles for radiation therapy.

The efficacy of concurrent cisplatin and 5-flurouracil chemotherapy and radiation therapy for locally advanced cancer of the uterine cervix

OBJECTIVE

To evaluate the efficacy of concurrent chemoradiation (CCRT) using 5-flurouracil (5-FU) and cisplatin for locally advanced cervical cancer.

METHODS

We reviewed the medical records of 57 patients with locally advanced cervical cancer (stage IIB-IVA and bulky IB2-IIA tumor) who underwent the CCRT at Dong-A University Hospital from January 1997 to June 2007. The CCRT consisted of 5-FU, cisplatin and pelvic radiation. Every three weeks, 75 mg/m(2) cisplatin was administered on the first day of each cycle and 5-FU was infused at the dose of 1,000 mg/m(2)/d from the second day to the fifth day of each cycle. Radiation was administered to the pelvis at a daily dose of 1.8 Gy for five days per week until a medium accumulated dose reached to 50.4 Gy. If necessary, the radiation field was extended to include paraaortic lymph nodes. Consolidation chemotherapy was performed using 5-FU and cisplatin.

RESULTS

Fifty-seven patients were enrolled and the median follow-up duration was 53 months (range 7-120 months). The overall response rate was 91.5% (74% complete response and 17.5% partial response). The 5-year overall survival and 3-year progression free survival rates were 69.4% and 74.9%, respectively. During the follow-up period (median 23 months, range 7-60 months), fourteen patients were diagnosed as recurrent disease.

CONCLUSION

CCRT with 5-FU and cisplatin which is the primary treatment for patients with locally advanced cervical cancer was effective and well tolerated.

Chemotherapy in the primary treatment of cervical carcinoma

Two major treatment modalities in cervical cancer include radiotherapy and surgery. In an attempt to improve the outcome, these modalities have been increasingly supplemented by chemotherapy. Chemotherapy can be combined with local therapies in various sequences. Of the two possible strategies using chemotherapy and radiotherapy (sequential or concomitant), the latter seems to be more effective. Platinum-based regimens applied concurrently with both definitive and post-operative radiation therapy were demonstrated to provide survival benefit in five of the six recently published randomised trials. The positive impact of chemotherapy added to radiotherapy has also been shown in a meta-analysis including 1894 patients in 19 randomised studies. This strategy, however, is accompanied by increased early toxicity. The benefit of chemotherapy applied prior to surgery remains debatable. The role of new cytotoxic and biological substances, as well as agents combating tumour hypoxia, warrants further clinical investigation.

Concurrent weekly cisplatin and radiotherapy in routine management of cervical cancer: a report on patient compliance and acute toxicity

PURPOSE

To evaluate patient compliance and acute toxicity accompanying concurrent weekly cisplatin and radiotherapy (RT) in the routine management of cervical cancer.

METHODS AND MATERIALS

Locally advanced or high-risk early-stage cervical cancer patients treated with RT and concurrent weekly cisplatin at a dose of 40 mg/m(2) i.v. (maximum dose, 70 mg) for five cycles. Definitive RT included whole pelvis external beam RT to the International Commission on Radiation Units and Measurements reference dose of 40 Gy plus a 10-Gy boost to the parametrium and two brachytherapy applications of 20 Gy to point A each. Postoperative RT consisted of pelvic external beam RT to the International Commission on Radiation Units and Measurements reference dose of 50 Gy and one brachytherapy application of 30 Gy at a depth of 0.5 cm from the applicator surface.

RESULTS

Included in this analysis were 112 consecutive cervical cancer patients treated at one institution with concurrent cisplatin and RT between May 1999 and September 2002. The median age was 48 years (range, 28-79 years). Definitive RT was administered to 57 International Federation of Gynecology and Obstetrics "bulky" Stage IB or IIB-IVA patients, and 53 patients underwent postoperative RT; 2 patients underwent RT for stump carcinoma. All but 2 patients (both administered definitive RT) completed RT. A total of 454 cisplatin cycles were administered (median 4 cycles/patient, range 1-6). Overall, 74% of patients received at least four cycles of cisplatin. The planned five cisplatin cycles were administered to 50 patients (45%); 42% were irradiated definitively and 47% postoperatively. The full and timely planned cisplatin dose was administered to 29 patients (26%). For 29% of patients, the interval between cycles was prolonged because of toxicity (n = 11; 10%) or for reasons not related to toxicity (n = 10; 9%). Of the 112 patients, 62 (55%) did not undergo the planned five cycles of cisplatin because of treatment toxicity (n = 35; 31%) or noncompliance with the treatment schedule because of delayed administration of the first cycle or omission of a cycle for reasons other than toxicity (n = 23; 21%). The most common side effects resulting in chemotherapy discontinuation included GI complications (n = 7) and impaired renal function (n = 5). Of the 112 patients, 49 (44%) experienced Grade 1 or 2 leukopenia and 6 (5%) Grade 3 or 4 leukopenia.

CONCLUSION

Our results show that pelvic RT combined with weekly cisplatin in cervical cancer patients is accompanied by considerable acute toxicity. Furthermore, a number of patients were unable to comply with the treatment schedule owing to reasons unrelated to treatment toxicity. Thus, administration of the full chemotherapy dose may be difficult, although the delivery of planned RT was generally not compromised. Additional follow-up is needed to assess the late toxicity of combined modality treatment.

Adding concurrent low dose continuous infusion of cisplatin to radiotherapy in locally advanced cervical carcinoma: a prospective randomized pilot study

The tolerability and efficacy of the continuous infusion of cisplatin during radiotherapy was studied by tumour response, survival and pelvic control, in carcinoma of the cervix. 44 patients with stage IIB-IIIB cervical carcinoma were prospectively randomized into two groups: radiation alone (control group) versus radiation plus cisplatin (study group). While there was no significant difference in diarrhoea and urinary complication scores, emesis and appetite changes were significantly greater in the study group. Tumour responses were no different at the end of the treatment and 3 months after completion of treatment. After 40 months median follow-up, 40/44 patients were assessed (one had a second primary tumour and three were lost to follow-up). Persistent disease was found in 3 patients: one in the study arm and two in the control arm. Recurrence was seen in 10 patients in the first 2 years. 5-year pelvic control rates were; 69.4% and 63.9% (p=0.7), survival rates were 52.0% and 48.9% (p=0.7) and disease-free survival rates were 67.5% and 58.7% (p=0.3) for the control and the study groups, respectively. Although the continuous infusion of cisplatin during radiotherapy was well tolerated, this additional treatment did not appear to show an improvement in pelvic control, survival, or disease-free survival.

Le traitement par neutrons : hadronthérapie partie II : bases physiques et expérience clinique

Neutrons have radiobiological characteristics, which differ from those of conventional radiotherapy beams (photons) and which offer a theoretical advantage over photons to fight radioresistance by the differential relative biological effect of them between normal and tumour tissues. Neutron therapy beneficed of great interest between 1975 and 1985. Many of phase III trials were conducted and indications have been definitively deducted of them. After briefly describing the properties of neutron beams, this review discusses the indication of neutron therapy on the basis of the clinical results. Salivary, prostate tumours and sarcomas are the main indications of neutron therapy. In concern to the prostate cancers, other alternative treatments reduce the neutron therapy field. For sarcomas, the lack of randomised trials limits the impact of the interest of neutrons. For other tumours, the ratio benefice/risk of neutron therapy is inferior to these obtained with photons and they could not be considered like classical indications.

Concurrent mitomycin C, 5-fluorouracil, and radiotherapy in the treatment of locally advanced carcinoma of the cervix: a randomized trial

PURPOSE

This is a prospective, Phase III multicenter randomized trial to assess the effectiveness of concurrent intravenous mitomycin C, oral 5-fluorouracil (5-FU), and radiotherapy (RT) in locally advanced carcinoma of the cervix.

METHODS AND MATERIALS

Between January 1988 and November 1994, 926 patients with locally advanced carcinoma of the cervix, FIGO Stage IIB-IVA, were entered into this study. The patients were randomized into four arms, as follows: Arm 1: conventional RT; Arm 2: conventional RT and adjuvant chemotherapy; Arm 3: conventional RT plus concurrent chemotherapy; Arm 4: conventional RT plus concurrent chemotherapy and adjuvant chemotherapy. Concurrent chemotherapy consisting of intravenous mitomycin C at 10 mg/m(2) was given on Days 1 and 29, and oral 5-FU at 300 mg/day was administered on Days 1-14 and 29-42 during RT. Adjuvant chemotherapy of 5-FU orally at 200 mg/day was given for three courses of 4 weeks, with a 2-week rest every 6 weeks. Six centers participated in the trial.

RESULTS

The median follow-up time was 89 months. Acute side effects were generally higher in concurrent arms, but most of the patients tolerated the treatment well. Bone marrow toxicity was also higher in concurrent arms. The 5-year actuarial disease-free survival (DFS) was 48.2%, 54.1%, 64.5%, and 59.7% for arms 1, 2, 3, and 4, respectively. The pattern of failure revealed a significant increase in locoregional recurrence in the nonconcurrent chemoradiotherapy arm. The local recurrence was 25.5%, 20.6%, 14.3%, and 17.6% for arms 1, 2, 3, and 4, respectively. The metastatic rates were not significantly different in all four arms. At the time of analysis, there were no increases in late side effects, especially in gastrointestinal and genitourinary systems.

CONCLUSIONS

Concurrent chemotherapy, mitomycin C, and 5-FU together with conventional RT showed an improved DFS rate when compared with conventional RT alone in patients with locally advanced carcinoma of the cervix.

Chemoradiotherapy for cervical cancer

Cervical cancer remains a major health problem worldwide, despite advances in screening. For patients with locally advanced stage disease, failure to obtain local-regional control usually results in death. In an effort to improve local-regional tumour control, neoadjuvant and concurrent chemoradiation has been tested. Recently, five randomised trials performed by the Gynecologic Oncology Group (GOG), Radiation Therapy Oncology Group (RTOG) and the SouthWest Oncology Group (SWOG) studying cisplatin-based chemoradiation have demonstrated a significant survival advantage. Three of the trials compared cisplatin-based concurrent chemotherapy and radiation to radiation alone and two trials compared cisplatin-based concurrent chemotherapy and radiation to radiation with hydroxyurea. In all of the trials, cisplatin-based chemotherapy administered concurrently with radiation therapy was more effective at reducing the risk of death by 30-50%. Acute toxicities, principally neutropenia and gastrointestinal, were more common with chemoradiation, but were transient and the rates of late complications (complications that persisted or occurred for more than 60 days after the treatment) were similar. Based on the results of these five randomised trials, the National Cancer Institute (NCI) released a Clinical Announcement stating that cisplatin-based chemotherapy, as used in these trials (i.e. concurrently with radiation therapy), as the new standard of therapy for cervical cancer.

Interim results of a randomized trial of mitomycin C as an adjunct to radical radiotherapy in the treatment of locally advanced squamous-cell carcinoma of the cervix

The purpose of this study was to determine the efficacy of mitomycin C as an adjunct to radiotherapy for the treatment of locally advanced cervix cancer. Patients with squamous-cell carcinoma of the cervix, stages IB2-IVA, were randomized to receive radiotherapy alone or radiotherapy with concomitant mitomycin C. An initial cohort of 160 patients, having a mean follow-up of 46 months, is analyzed. Intravenous mitomycin C, 15 mg/M(2), was given on the first and sixth week of radiotherapy. The 78 patients in the radiotherapy with mitomycin C group and 82 patients in the radiotherapy alone group have a comparable distribution by age and stage (mean age 47 years; stage IB 3%, IIA 11%, IIB 48%, IIIA 1%, IIIB 36%, IVA 3%). The four-year actuarial survival rates for radiotherapy with mitomycin C and radiotherapy alone were 72% and 56%, respectively (P = 0.13). The four-year actuarial disease-free survival rates for radiotherapy with mitomycin C and radiotherapy alone were 71% and 44%, respectively, a statistically significant difference (P = 0.01). The four-year actuarial local recurrence-free survival rates for patients receiving radiotherapy with mitomycin C and radiotherapy alone were 78% and 63%, respectively (P = 0.11). Differences in four-year distant recurrence-free survival between radiotherapy plus mitomycin C and radiotherapy alone were significantly different at 85% vs. 61% (P = 0.01); this analysis is not adjusted for local failure. On subgroup analysis, stage III-IVA patients had a four-year actuarial disease-free survival of 75% for radiotherapy plus mitomycin C compared with 35% for radiotherapy alone (P = 0.03). There were no treatment- related deaths. Mild hematologic toxicity was seen only in the group treated with mitomycin C. No excess in non-hematologic toxicity has been observed thus far with combined mitomycin C and radiotherapy. In this open phase III trial of mitomycin C as an adjunct to radical radiotherapy for squamous-cell carcinoma of the cervix, there were minimal hematologic effects and no increase in acute radiation reactions. A statistically significant difference in favor of patients receiving mitomycin C is shown for disease-free survival. Thus far, there are trends in favor of those patients receiving mitomycin C for survival and local control. Patients with more advanced stage disease, predominantly stage IIIB, appear to have the most benefit. These preliminary results support the hypothesis that targeting hypoxic cells may lead to a therapeutic enhancement in the radiotherapy of cervix cancer. This trial continues to accrue patients and follow-up data. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 206-223 (2000).

Radiation Therapy Oncology Group clinical trials for carcinoma of the cervix

Grigsby PW. Radiation Therapy Oncology Group clinical trials for carcinoma of the cervix. The purpose of this paper is to review the primary data of the clinical trials performed by the Radiation Therapy Oncology Group (RTOG) for patients with carcinoma of the uterine cervix. The trials, their strengths, limitations, and the implications of the results are discussed. During the past 25 years there have been several clinical trials performed by the RTOG to test various hypotheses for improving local control and survival for patients with carcinoma of the uterine cervix. The major research themes that have been appraised are the use of hyperbaric oxygen, altered fractionation radiotherapy, hypoxic cell sensitization, chemo-sensitization, prophylactic paraaortic irradiation, and neutron radiotherapy. There are two general research themes. The initial RTOG trials for cervical cancer attempted to address the issues of tumor volume and hypoxic cells while the latter studies addressed these issues and the issue of micrometastatic disease. The phase III clinical trials performed by the RTOG have not demonstrated a local control or survival advantage in the experimental arm with the use of hyperbaric oxygen, split-course radiotherapy, hypoxic cell sensitization, or neutron radiotherapy. Acceptable toxicity and efficacy results were shown in phase II studies evaluating twice-daily irradiation and chemo-sensitization. The positive phase III trials were RTOG 79-20 which evaluated prophylactic paraaortic irradiation in patients with bulky stages IB, IIA, and IIB disease, and RTOG 90-01 which evaluated concurrent chemotherapy. Results of more recent clinical trials are pending their completion.

Figo IIIB squamous cell carcinoma of the cervix: an analysis of prognostic factors emphasizing the balance between external beam and intracavitary radiation therapy

PURPOSE

To define patient, tumor, and treatment factors that influence the outcome of patients with FIGO Stage IIIB squamous cell carcinoma of the intact uterine cervix.

METHODS AND MATERIALS

The records of 1,096 patients treated with radiation therapy between 1960 and 1993 for FIGO Stage IIIB squamous cell carcinoma of the intact uterine cervix were reviewed retrospectively. Of these, 983 (90%) were treated with curative intent and 113 were treated only to achieve palliation of symptoms. Of 907 patients who completed the intended curative treatment, 641 (71%) were treated with a combination of external beam irradiation (EBRT) and intracavitary irradiation (ICRT) and 266 (29%) were treated with EBRT only. The median duration of treatment for these 907 patients was 51 days. Between 1966 and 1980, only 52% of patients who completed treatment with curative intent received ICRT, compared with 92% of patients treated during 1981-1993, an increase that reflects an evolution in the philosophy of treatment for advanced tumors. In general, the intensity of ICRT correlated inversely with the dose of EBRT to the,central pelvis. Median follow-up of surviving patients was 134 months.

RESULTS

For 983 patients treated with initial curative intent, disease-specific survival (DSS) was significantly worse for those who were < 40 years old, had experienced more than a 10% weight loss, or had a hemoglobin level < 10 g/dl before or during radiation therapy. Tumor factors that correlated with a relatively poor DSS were bilateral pelvic wall involvement, clinical tumor diameter > or = 8 cm, hydronephrosis, lower vaginal involvement, and evidence of lymph node metastases on lymphangiogram (p < 0.01 in all cases). For the 907 patients who completed treatment with curative intent, 641 who had ICRT had a DSS of 45% at 5 years, compared with 24% for those treated with EBRT alone (p < 0.0001). Those who received > 52 Gy of EBRT to the central pelvis had DSS rates of 27-34%, compared with 53% for patients treated with lower doses of EBRT to the central pelvis and more intensive ICRT (p < 0.0001). At 5 years, the actuarial risk of major complications was also greater for patients treated with > 52 Gy of EBRT to the central pelvis (57-68%), compared with those who had 48-52 Gy (28%) and those who had < or = 47 Gy of EBRT to the central pelvis (15%) (p < 0.0001). Outcome was also compared for four time periods during which different treatment policies were in place for patients with Stage IIIB disease. The highest DSS (51%) and lowest actuarial complication rate (17%) were achieved during the most recent period (1981-1993) when modest doses of EBRT were combined with relatively intensive ICRT (p < 0.01 for both comparisons).

CONCLUSION

Aggressive use of ICRT, carefully balanced with pelvic EBRT, is necessary to achieve the best ratio between tumor control and complications for patients with FIGO Stage IIIB carcinoma of the cervix. In our experience, the highest DSS rates and the lowest complication rates were achieved with a combination of 40-45 Gy of EBRT combined with ICRT.

Particle beam therapy (hadrontherapy): basis for interest and clinical experience

The particle or hadron beams deployed in radiotherapy (protons, neutrons and helium, carbon, oxygen and neon ions) have physical and radiobiological characteristics which differ from those of conventional radiotherapy beams (photons) and which offer a number of theoretical advantages over conventional radiotherapy. After briefly describing the properties of hadron beams in comparison to photons, this review discusses the indications for hadrontherapy and analyses accumulated experience on the use of this modality to treat mainly neoplastic lesions, as published by the relatively few hadrontherapy centres operating around the world. The analysis indicates that for selected patients and tumours (particularly uveal melanomas and base of skull/spinal chordomas and chondrosarcomas), hadrontherapy produces greater disease-free survival. The advantages of hadrontherapy are most promisingly realised when used in conjunction with modern patient positioning, radiation delivery and focusing techniques (e.g. on-line imaging, three-dimensional conformal radiotherapy) developed to improve the efficacy of photon therapy. Although the construction and running costs of hadrontherapy units are considerably greater than those of conventional facilities, a comprehensive analysis that considers all the costs, particularly those resulting from the failure of less effective conventional radiotherapy, might indicate that hadrontherapy could be cost effective. In conclusion, the growing interest in this form of treatment seems to be fully justified by the results obtained to date, although more efficacy and dosing studies are required.

Treatment of carcinoma of the uterine cervix with concomitant cisplatin, 5-fluorouracil and split course hyperfractionated radiotherapy

To improve local and systemic control of bulky (>4 cm) and/or advanced primary cancer of the uterine cervix, 35 patients were treated with concomitant cisplatin (CDDP), 5-fluorouracil (5-FU) and split course hyperfractionated radiotherapy. Radiation was administered to the pelvis in five-day courses at a dose of 1.5 Gy twice daily every 21 days until a median dose of 45 Gy was reached. 15 Gy more were administered to involved parametrium or central tumor by external radiotherapy or brachytherapy. The irradiated zone was extended to include paraaortic lymph nodes if necessary. CDDP was administered at a dose of 20 mg m(-2) and 5 FU at a dose of 500 mg m(-2) from day one to day five of each course. The median number of combined treatment courses per patient was four (1-6). Local responses were obtained in 19 out of 24 patients in whom evaluation was feasible (i.e. who did not undergo surgery prior to combined therapy). Median survival was not attained with a median follow up of 33 months, three year overall survival was 62% and 52% in patients with local control and in the whole population respectively. Several patients with stage III and IV tumors achieved a very long survival. Acute toxicity was manageable but three patients required surgical repair of late radiation complications. This combined chemotherapy and radiotherapy resulted in good local control and did not rule out surgery.

Concurrent 5-fluorouracil, mitomycin C and irradiation in locally advanced cervix cancer

We reviewed 177 patients treated with radical radiotherapy for locally advanced (FIGO stages IIB, IIIA, IIIB) cervix cancer between January 1979 and December 1989. The radiotherapy was given by external beam treatment to the pelvis and by an intracavitary caesium insertion. Ninety-three patients also received chemotherapy which consisted of infusional 5-fluorouracil during the first and last weeks of the external beam component of the radiotherapy, combined with bolus mitomycin C (group A, 64 patients) or without mitomycin C (group B, 29 patients). These groups were compared with patients treated by radiotherapy alone (group C, 84 patients). The median follow-up was 7.2 years. The median survival time for all patients was 47 months, but was significantly higher (87 months, p = 0.004) for group A. Rates of relapse-free survival and local control were also higher in group A. Toxicity was assessed in detail using the Franco-Italian glossary. There was a relatively high rate of complications, particularly in group A, with 36% of patients having grade 3 or 4 complications. This increase in toxicity persisted through all follow-up time intervals. Patients in group B also demonstrated a higher rate of toxicity than group C, but this increase was limited to the first 6 months of follow-up. The use of mitomycin C in addition to radiotherapy and 5-fluorouracil should be regarded with caution, as other studies have also shown that toxicity is increased, but without improvements in survival.

Twice-daily fractionation of external irradiation with brachytherapy in bulky carcinoma of the cervix. Phase I/II study of the Radiation Therapy Oncology Group 88-05

BACKGROUND

Hyperfractionated radiation therapy (HFX), which may permit higher total doses of radiation therapy without increased toxic effects to normal tissues, has been used with pelvic tumors, but its combination with brachytherapy has not been well studied.

METHODS

A prospective Phase I/II trial was designed to study HFX with brachytherapy in patients with bulky Stage IB and IIA, IIB, III, and IVA carcinomas of the cervix. HFX doses of 1.2 Gy were administered to the whole pelvis twice daily at 4-6 hour intervals, 5 days per week; the total dose to the whole pelvis was 24-48 Gy. External pelvic irradiation was followed by one or two intracavitary applications to deliver the total minimum dose of 85 Gy at point A and 65 Gy to the lateral pelvic nodes.

RESULTS

Eighty-one patients were enrolled in this protocol; 14% had Stage IB, 43% stage II, 38% stage III, and 4% stage IVA carcinomas. Seventy-one patients were evaluable for HFX and brachytherapy; 38 patients received one intracavitary application, and 33 received two applications. Four patients had Grade 3 acute reactions. The cumulative rates of Grade 3-4 late toxicities were 1.9% at 1 year, and 6.3% at 2 and 3 years. Of 80 patients evaluated for response, 80% had complete disappearance of disease. Comparisons with historical rates of late toxicity with standard fractionation (STD) revealed similar results in spite of higher total doses with HFX. Comparisons between historical STD and HFX also revealed equivalent rates of pelvic tumor control, Grade 3-4 toxicity, and survival at 3 years.

CONCLUSIONS

Results suggest that combined with brachytherapy, HFX at total parametrial doses 10% above those used with STD was tolerated and at least as effective as STD. Further study with higher doses and extended fields is indicated. Comparisons of long term (5-plus years) survival and late-effects rates with STD versus HFX are planned.

Development of fast neutron therapy worldwide. Radiobiological, clinical and technical aspects

Radiobiological data indicate that fast neutrons could bring a benefit in the treatment of some tumour types, and suggest mechanisms through which this benefit could be achieved. However, radiobiology also clearly indicates that there is a need for patient selection as well as for a high-physical selectivity. The main difficulty when interpreting the results of neutron therapy are the poor technical conditions in which the first treatments were applied. This explains why the value and the place of neutron therapy are not universally recognized, although more than 15,000 patients have been treated so far worldwide. There are, however, clinical indications of fast neutrons bringing a benefit for the following tumour sites: salivary glands, paranasal sinuses, soft tissue sarcomas, prostatic adenocarcinomas, palliative treatment of melanoma and rectum. These tumours represent about 10-15% of all patients currently referred to the radiation therapy departments.

An evaluation of the results of neutron therapy trials

Twenty-five randomised clinical trials have been completed which have investigated the value of fast neutron therapy. The results of these trials are reviewed in terms of the reported rates of local tumour control and late morbidity. The trials have included patients with cancers of the head and neck region, brain, lung, pancreas, cervix, bladder and rectum. None has demonstrated neutrons to be advantageous compared with photons. Two trials of locally advanced prostate cancer have given conflicting results. A trial of mixed schedule therapy has demonstrated improved local tumour control and survival. A trial of neutrons alone for similar stage disease has not shown any therapeutic advantages. It is still claimed that salivary gland tumours may be more effectively treated by neutrons but the clinical trial results are not definitive. Late morbidity after neutron therapy is a persistent cause for concern and often has been unacceptably high. There is no convincing evidence that fast neutrons are either as safe or as effective in cancer control as photon therapy.

Weekly cisplatin plus external beam radiotherapy and high dose rate brachytherapy in patients with locally advanced carcinoma of the cervix

PURPOSE

Prospective, single arm, Phase I/II trial performed to assess the efficacy and toxicity of the concomitant use of weekly cisplatin and pelvic radiotherapy in patients with locally advanced carcinoma of the cervix.

METHODS AND MATERIALS

Between December 1988 and April 1991, 50 previously untreated patients with bulky, locally advanced, squamous cell carcinoma entered the study. All patients were evaluated by a gynecologist and a radiation oncologist and were submitted to standard pre-treatment staging procedures. The International Federation of Gynecology and Obstetrics stage distribution was as follows: IIA three patients, IIB seventeen, IIIA two, IIIB 25, and IVA three. Radiotherapy consisted of 46 Gy external beam irradiation plus three high dose rate intracavitary treatments given on a weekly basis to a total dose of 30 Gy to point A. Cisplatin 30 mg/m2 was also given weekly starting on day 1 of radiotherapy.

RESULTS

With a median follow-up time of 27 months, complete response was seen in 88% (44/50) of the patients. The actuarial survival rate at 44 months was 65%. Total pelvic failure rate was 26% (13/50). Of the 44 patients who achieved a complete remission, only seven have failed in the pelvis. Distant disease was observed in 24% of the cases. Treatments were well tolerated with no patient requiring an interruption in the radiotherapy. However, the incidence of late gastrointestinal toxicity was high, with 10 patients developing a rectal ulcer (four colostomies for severe bleeding), two patients a small bowel obstruction, and two patients a recto-vaginal fistula. Moreover, gastrointestinal complications appeared sooner than expected, at a median follow-up time of 11 months after completion of treatment.

CONCLUSION

The combination of weekly cisplatin and radiotherapy appears to be a very effective regimen for patients with locally advanced carcinoma of the cervix, but resulted in a relatively high frequency of late gastrointestinal complications.

The potential for proton beam therapy in locally advanced carcinoma of the cervix

Advanced cervix cancer has a local failure rate of 40-45% when treated with a combination of external beam irradiation and intracavitary implants, and approximately 60-65% when treated by external beam irradiation alone. Because of the absorption characteristics of protons, there is the potential for improved dose distributions and delivery of greater total doses to cervical neoplasms. Using computer-modelled examples, this theoretical advantage has been tested and the results have been extrapolated to show a therapeutic advantage in local control and morbidity. The first example shows the use of protons and intracavitary implants in advanced cervix tumors. Larger tumor doses are possible with protons than with photons, while the dose-volume to normal structures is decreased. In the second example, external proton beam treatment alone also reveals significantly higher tumor doses and lower normal tissue doses, compared to photon irradiation. With new proton therapy facilities being designed and built in the United States and overseas, protocols are being designed to evaluate the therapeutic potential of proton therapy in locally advanced cervix cancer.

High energy neutron treatment for pelvic cancers: study stopped because of increased mortality

OBJECTIVE

To compare high energy fast neutron treatment with conventional megavoltage x ray treatment in the management of locally advanced pelvic carcinomas (of the cervix, bladder, prostate, and rectum).

DESIGN

Randomised study from February 1986; randomisation to neutron treatment or photon treatment was unstratified and in the ratio of 3 to 1 until January 1988, when randomisation was in the ratio 1 to 1 and stratified by site of tumour.

SETTING

Mersey regional radiotherapy centre at Clatterbridge Hospital, Wirral.

PATIENTS

151 patients with locally advanced, non-metastatic pelvic cancer (27 cervical, 69 of the bladder, seven prostatic, and 48 of the rectum).

INTERVENTION

Randomisation to neutron treatment was stopped in February 1990.

MAIN OUTCOME MEASURES

Patient survival and causes of death in relation to the development of metastatic disease and treatment related morbidity.

RESULTS

In the first phase of the trial 42 patients were randomised to neutron treatment and 14 to photon treatment, and in the second phase 48 to neutron treatment and 47 to photon treatment. The relative risk of mortality for photons compared with neutrons was 0.66 (95% confidence interval 0.40 to 1.10) after adjustment for site of tumour and other important prognostic factors. Short term and long term complications were similar in both groups.

CONCLUSIONS

The trial was stopped because of the increased mortality in patients with cancer of the cervix, bladder, or rectum treated with neutrons.

Preliminary results of concurrent radiotherapy and chemotherapy in advanced cervical carcinoma: a phase I-II prospective intergroup NCOG-RTOG Study

Thirty-eight patients with advanced carcinoma of the cervix were prospectively treated with a concurrent combination of radiotherapy (RT) and chemotherapy (CT) using the drugs 5-fluorouracil (5FU), mitomycin C and cis-platinum as part of a Northern California Oncology Group (NCOG) and Radiation Therapy Oncology Group (RTOG) intergroup study. RT consisted of 36.00 Gy to the pelvis in 4 weeks followed by a 9.00-Gy parametrial boost. This was followed by two intracavitary applications for a total of 4000 mg hr of radium equivalent when possible. 5FU (1000 mg/m2/24 hr for 96 hr by iv infusion) and mitomycin C (10 mg/m2/iv bolus) were given during the second week of external RT. 5FU (dose as above) and cis-platinum (75 mg/m2/iv over 6 hr) were given during the first intracavitary application. Of 36 patients evaluable for toxicity, 11% had grade 3 nonhematological toxicity and 11% had reversible grade 4 hematological toxicity. There were no toxic deaths. A complete response rate of 62.5% was obtained overall (median survival not reached). This study suggests that this particular combination of RT and CT in advanced cervical carcinoma is effective and well tolerated.

Review of the clinical results of fast neutron therapy

The clinical results reported from the different neutron therapy centres are reviewed. Fast neutrons were shown to be useful in the treatment of locally extended inoperable salivary gland tumours (average local control rates 67% for neutrons compared to 28% for photons). For paranasal sinuses and some tumours of the head and neck area, especially extended tumours with large fixed lymph nodes, neutrons could also be of interest. By contrast, the results obtained for brain tumours were, in general, disappointing. Neutrons were shown to be beneficial in the treatment of well differentiated soft tissue sarcomas, as well as to bone- and chondrosarcomas. For locally extended prostatic adenocarcinoma, a RTOG randomized trial gave local control rates of 77% for mixed schedule compared to 31% for photons. Neutrons could be useful also for palliative treatment of melanomas. Further studies are needed in order to evaluate the benefit of fast neutrons for other localizations such as uterine cervix, bladder and rectum. It can be concluded that fast neutrons could be of interest for about 10% of the radiotherapy patients, but it is likely that the new high-energy hospital-based cyclotrons will further extend the indications of neutron therapy. However, patient selection remains one of the main problems and there is a need for development of individual predictive tests.